si5351: additional functions needed for more advanced and power saving usage scenarios

Signed-off-by: deadprogram <ron@hybridgroup.com>

.github/workflows/build.yml

@@ -11,13 +11,12 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    container: ghcr.io/tinygo-org/tinygo-dev:latest
+    container:
+      image: ghcr.io/tinygo-org/tinygo:latest
+      options: --user root
     steps:
-      - name: Work around CVE-2022-24765
-        # We're not on a multi-user machine, so this is safe.
-        run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
       - name: TinyGo version check
         run: tinygo version
       - name: Enforce Go Formatted Code
@@ -25,4 +24,6 @@ jobs:
       - name: Run unit tests
         run: make unit-test
       - name: Run build and smoke tests
-        run: make smoke-test
+        run: |
+          go env -w GOFLAGS=-buildvcs=false
+          make smoke-test

CHANGELOG.md

@@ -1,3 +1,56 @@
+0.34.0
+---
+- **core**
+    - add regmap package to facilitate heapless driver development
+    - PinInput+PinOutput HAL (#753, reloaded) (#795)
+    - Add Device8I2C/SPI types and their logic (#801)
+
+- **new devices**
+    - **bno8x**
+        - Add support for CEVA BNO08x 9DoF sensor (#809)
+    - **hineyhsc**
+        - Add Honeywell HSC TruStability SPI+I2C pressure sensor driver (#799)
+    - **p25q16h**
+        - added support for P25Q16H flash chip for xiao-ble target
+    - **si5351**
+        - add support for si5351 (#810)
+    - **w25q80dv**
+        - added support for W25Q80DV flash chip for xiao-ble target
+    - **w5500**
+        - initial version the driver (#788)
+
+- **enhancements**
+    - **ds3231**
+        - DS3231 Alarm features (#805)
+    - **general**
+        - add simplest driver ports
+    - **lis3dh**
+        - add Update and Acceleration calls
+        - use correct error handling and make configurable
+    - **lsm9ds1**
+        - avoid unnecessary heap allocations
+    - **pixel**
+        - add Grayscale2bit color (#817)
+    - **scd4x**
+        - add support for SCD41 single-shot measurements
+        - remove dead code
+        - update package to use standard methods
+    - **si5351**
+        - add many missing functions needed for convenient use.
+    - **ssd1xxx**
+        - break dependency from machine package (#812)
+    - **test**
+        - Add TestImageRGB888 and TestImageRGB555
+
+- **bugfixes**
+    - **quadrature**
+        - add RP2350 to quadrature_interrupt.go
+    - **pixel**
+        - correct logic error in image size checks in pixel's tests
+        - correct logic error in image size checks in pixel's tests (Monochrome)
+        - correct RGB555 to RGBA conversion logic
+
+
 0.33.0
 ---
 - **new devices**

README.md

@@ -3,7 +3,7 @@
 [![PkgGoDev](https://pkg.go.dev/badge/tinygo.org/x/drivers)](https://pkg.go.dev/tinygo.org/x/drivers) [![Build](https://github.com/tinygo-org/drivers/actions/workflows/build.yml/badge.svg?branch=dev)](https://github.com/tinygo-org/drivers/actions/workflows/build.yml)
 
 
-This package provides a collection of over 100 different hardware drivers for devices such as sensors, displays, wireless adaptors, and actuators, that can be used together with [TinyGo](https://tinygo.org).
+This package provides a collection of over 130 different hardware drivers for devices such as sensors, displays, wireless adaptors, and actuators, that can be used together with [TinyGo](https://tinygo.org).
 
 For the complete list, please see:
 https://tinygo.org/docs/reference/devices/

apa102/apa102.go

@@ -5,9 +5,10 @@ package apa102 // import "tinygo.org/x/drivers/apa102"
 
 import (
 	"image/color"
-	"machine"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 const (
@@ -37,8 +38,11 @@ func New(b drivers.SPI) *Device {
 
 // NewSoftwareSPI returns a new APA102 driver that will use a software based
 // implementation of the SPI protocol.
-func NewSoftwareSPI(sckPin, sdoPin machine.Pin, delay uint32) *Device {
-	return New(&bbSPI{SCK: sckPin, SDO: sdoPin, Delay: delay})
+func NewSoftwareSPI(sckPin, sdoPin pin.Output, delay uint32) *Device {
+	return New(&bbSPI{SCK: sckPin.Set, SDO: sdoPin.Set, Delay: delay, configurePins: func() {
+		legacy.ConfigurePinOut(sckPin)
+		legacy.ConfigurePinOut(sdoPin)
+	}})
 }
 
 // WriteColors writes the given RGBA color slice out using the APA102 protocol.

apa102/softspi.go

@@ -1,6 +1,9 @@
 package apa102
 
-import "machine"
+import (
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
+)
 
 // bbSPI is a dumb bit-bang implementation of SPI protocol that is hardcoded
 // to mode 0 and ignores trying to receive data. Just enough for the APA102.
@@ -8,15 +11,18 @@ import "machine"
 // most purposes other than the APA102 package. It might be desirable to make
 // this more generic and include it in the TinyGo "machine" package instead.
 type bbSPI struct {
-	SCK   machine.Pin
-	SDO   machine.Pin
-	Delay uint32
+	SCK           pin.OutputFunc
+	SDO           pin.OutputFunc
+	Delay         uint32
+	configurePins func()
 }
 
 // Configure sets up the SCK and SDO pins as outputs and sets them low
 func (s *bbSPI) Configure() {
-	s.SCK.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	s.SDO.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	if s.configurePins == nil {
+		panic(legacy.ErrConfigBeforeInstantiated)
+	}
+	s.configurePins()
 	s.SCK.Low()
 	s.SDO.Low()
 	if s.Delay == 0 {

bmi160/bmi160.go

@@ -1,31 +1,36 @@
 package bmi160
 
 import (
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 // DeviceSPI is the SPI interface to a BMI160 accelerometer/gyroscope. There is
 // also an I2C interface, but it is not yet supported.
 type DeviceSPI struct {
 	// Chip select pin
-	CSB machine.Pin
+	csb pin.OutputFunc
 
 	buf [7]byte
 
 	// SPI bus (requires chip select to be usable).
-	Bus drivers.SPI
+	bus           drivers.SPI
+	configurePins func()
 }
 
 // NewSPI returns a new device driver. The pin and SPI interface are not
 // touched, provide a fully configured SPI object and call Configure to start
 // using this device.
-func NewSPI(csb machine.Pin, spi drivers.SPI) *DeviceSPI {
+func NewSPI(csb pin.Output, spi drivers.SPI) *DeviceSPI {
 	return &DeviceSPI{
-		CSB: csb, // chip select
-		Bus: spi,
+		csb: csb.Set, // chip select
+		bus: spi,
+		configurePins: func() {
+			legacy.ConfigurePinOut(csb)
+		},
 	}
 }
 
@@ -33,9 +38,11 @@ func NewSPI(csb machine.Pin, spi drivers.SPI) *DeviceSPI {
 // configures the BMI160, but it does not configure the SPI interface (it is
 // assumed to be up and running).
 func (d *DeviceSPI) Configure() error {
-	d.CSB.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.CSB.High()
-
+	if d.configurePins == nil {
+		return legacy.ErrConfigBeforeInstantiated
+	}
+	d.configurePins()
+	d.csb.High()
 	// The datasheet recommends doing a register read from address 0x7F to get
 	// SPI communication going:
 	// > If CSB sees a rising edge after power-up, the BMI160 interface switches
@@ -86,9 +93,9 @@ func (d *DeviceSPI) ReadTemperature() (temperature int32, err error) {
 	data[0] = 0x80 | reg_TEMPERATURE_0
 	data[1] = 0
 	data[2] = 0
-	d.CSB.Low()
-	err = d.Bus.Tx(data, data)
-	d.CSB.High()
+	d.csb.Low()
+	err = d.bus.Tx(data, data)
+	d.csb.High()
 	if err != nil {
 		return
 	}
@@ -123,9 +130,9 @@ func (d *DeviceSPI) ReadAcceleration() (x int32, y int32, z int32, err error) {
 	for i := 1; i < len(data); i++ {
 		data[i] = 0
 	}
-	d.CSB.Low()
-	err = d.Bus.Tx(data, data)
-	d.CSB.High()
+	d.csb.Low()
+	err = d.bus.Tx(data, data)
+	d.csb.High()
 	if err != nil {
 		return
 	}
@@ -153,9 +160,9 @@ func (d *DeviceSPI) ReadRotation() (x int32, y int32, z int32, err error) {
 	for i := 1; i < len(data); i++ {
 		data[i] = 0
 	}
-	d.CSB.Low()
-	err = d.Bus.Tx(data, data)
-	d.CSB.High()
+	d.csb.Low()
+	err = d.bus.Tx(data, data)
+	d.csb.High()
 	if err != nil {
 		return
 	}
@@ -201,9 +208,9 @@ func (d *DeviceSPI) readRegister(address uint8) uint8 {
 	data := d.buf[:2]
 	data[0] = 0x80 | address
 	data[1] = 0
-	d.CSB.Low()
-	d.Bus.Tx(data, data)
-	d.CSB.High()
+	d.csb.Low()
+	d.bus.Tx(data, data)
+	d.csb.High()
 	return data[1]
 }
 
@@ -217,7 +224,7 @@ func (d *DeviceSPI) writeRegister(address, data uint8) {
 	buf[0] = address
 	buf[1] = data
 
-	d.CSB.Low()
-	d.Bus.Tx(buf, buf)
-	d.CSB.High()
+	d.csb.Low()
+	d.bus.Tx(buf, buf)
+	d.csb.High()
 }

bno08x/bno08x.go

@@ -0,0 +1,256 @@
+// Package bno08x provides a TinyGo driver for the Adafruit BNO08x 9-DOF IMU sensors.
+//
+// This driver implements the CEVA SH-2 protocol over the SHTP transport layer,
+// providing access to orientation, motion, and environmental sensors.
+//
+// Datasheet: https://www.ceva-ip.com/wp-content/uploads/BNO080_085-Datasheet.pdf
+package bno08x
+
+import (
+	"time"
+
+	"tinygo.org/x/drivers/internal/pin"
+)
+
+// Buser is the interface that wraps I2C or SPI bus operations.
+type Buser interface {
+	configure(address uint16, readChunk int) error
+	read(target []byte) (int, uint32, error)
+	write(data []byte) error
+	softReset() error
+}
+
+// Device represents a BNO08x sensor device.
+type Device struct {
+	bus      Buser
+	resetPin pin.OutputFunc
+
+	hal  *hal
+	shtp *shtp
+	sh2  *sh2Protocol
+
+	queue      [8]SensorValue
+	queueHead  int
+	queueTail  int
+	queueCount int
+
+	productIDs ProductIDs
+	lastReset  bool
+}
+
+// Config holds configuration options for the device.
+type Config struct {
+	// Address is the I2C address (used only for I2C bus).
+	Address uint16
+
+	// ResetPin is the optional hardware reset pin.
+	ResetPin pin.OutputFunc
+
+	// ReadChunk is the I2C read chunk size (used only for I2C bus).
+	ReadChunk int
+
+	// StartupDelay is the delay after reset (default: 100ms).
+	StartupDelay time.Duration
+}
+
+// Configure initializes the sensor and prepares it for use.
+func (d *Device) Configure(cfg Config) error {
+	// Configure bus-specific settings
+	if err := d.bus.configure(cfg.Address, cfg.ReadChunk); err != nil {
+		return err
+	}
+
+	if cfg.ResetPin != nil {
+		d.resetPin = cfg.ResetPin
+	}
+	if cfg.StartupDelay <= 0 {
+		cfg.StartupDelay = 100 * time.Millisecond
+	}
+
+	d.hal = newHAL(d)
+	d.shtp = newSHTP(d.hal)
+	d.sh2 = newSH2Protocol(d)
+
+	d.queueHead = 0
+	d.queueTail = 0
+	d.queueCount = 0
+	d.productIDs = ProductIDs{}
+	d.lastReset = false
+
+	if err := d.hal.open(); err != nil {
+		return err
+	}
+
+	// Now that handlers are registered, perform reset
+	// Try hardware reset first if available
+	if d.resetPin != nil {
+		d.hardwareReset()
+		time.Sleep(cfg.StartupDelay)
+	} else {
+		// No hardware reset pin - try soft reset via bus
+		if err := d.bus.softReset(); err != nil {
+			// If that fails, try soft reset via SHTP protocol
+			_ = d.sh2.softReset()
+			time.Sleep(50 * time.Millisecond)
+		}
+	}
+
+	// Wait for reset notification by actively polling
+	// The sensor should send reset complete message shortly after reset
+	deadline := time.Now().Add(1000 * time.Millisecond)
+	pollCount := 0
+	for time.Now().Before(deadline) {
+		pollCount++
+		if err := d.service(); err != nil {
+			// Ignore errors during initial polling - sensor might not be ready
+			time.Sleep(1 * time.Millisecond)
+			continue
+		}
+		if d.lastReset {
+			break
+		}
+		time.Sleep(1 * time.Millisecond)
+	}
+
+	if !d.lastReset {
+		return errTimeout
+	}
+
+	// NOTE: We intentionally skip the Initialize command (sh2_initialize)
+	// Testing revealed that sending the Initialize command (0xF2 0x00 0x04 0x01...)
+	// prevents the BNO08x from sending sensor reports on channel 3.
+	// The sensor works correctly without this command after a soft reset.
+	// The Arduino library likely works because it does a hardware reset which
+	// may put the sensor in a different state, or their initialization sequence
+	// differs in a way that doesn't trigger this issue.
+
+	// Request product IDs
+	if err := d.sh2.requestProductIDs(); err != nil {
+		return err
+	}
+
+	// Wait for product IDs with polling delay
+	deadline = time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		if err := d.service(); err != nil {
+			time.Sleep(10 * time.Millisecond)
+			continue
+		}
+		if d.productIDs.NumEntries > 0 {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	if d.productIDs.NumEntries == 0 {
+		return errTimeout
+	}
+
+	return nil
+}
+
+// EnableReport enables a specific sensor report at the given interval.
+func (d *Device) EnableReport(id SensorID, intervalUs uint32) error {
+	err := d.sh2.enableReport(id, intervalUs)
+	if err != nil {
+		return err
+	}
+
+	// Poll a few times to let the sensor process the command
+	// and potentially send acknowledgment
+	for i := 0; i < 10; i++ {
+		_ = d.service()
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	return nil
+}
+
+// GetSensorConfig retrieves the current configuration for a sensor.
+func (d *Device) GetSensorConfig(id SensorID) (SensorConfig, error) {
+	return d.sh2.getSensorConfig(id)
+}
+
+// SetSensorConfig sets the configuration for a sensor.
+func (d *Device) SetSensorConfig(id SensorID, config SensorConfig) error {
+	return d.sh2.setSensorConfig(id, config)
+}
+
+// WasReset returns true if the sensor signaled a reset since the last call.
+func (d *Device) WasReset() bool {
+	if d.lastReset {
+		d.lastReset = false
+		return true
+	}
+	return false
+}
+
+// GetSensorEvent retrieves the next available sensor event if present.
+func (d *Device) GetSensorEvent() (SensorValue, bool) {
+	if d.queueCount == 0 {
+		if err := d.service(); err != nil {
+			return SensorValue{}, false
+		}
+		if d.queueCount == 0 {
+			return SensorValue{}, false
+		}
+	}
+
+	value := d.queue[d.queueHead]
+	d.queueHead = (d.queueHead + 1) % len(d.queue)
+	d.queueCount--
+
+	return value, true
+}
+
+// ProductIDs returns the cached product identification information.
+func (d *Device) ProductIDs() ProductIDs {
+	return d.productIDs
+}
+
+// Service processes pending sensor data.
+// This is called automatically by GetSensorEvent but can be called manually
+// for more control over timing.
+func (d *Device) Service() error {
+	return d.service()
+}
+
+func (d *Device) enqueue(value SensorValue) {
+	next := (d.queueTail + 1) % len(d.queue)
+	if d.queueCount == len(d.queue) {
+		// Queue full, drop oldest
+		d.queueHead = (d.queueHead + 1) % len(d.queue)
+		d.queueCount--
+	}
+	d.queue[d.queueTail] = value
+	d.queueTail = next
+	d.queueCount++
+}
+
+func (d *Device) service() error {
+	if d.shtp == nil {
+		return nil
+	}
+	for {
+		processed, err := d.shtp.poll()
+		if err != nil {
+			return err
+		}
+		if !processed {
+			break
+		}
+	}
+	return nil
+}
+
+func (d *Device) hardwareReset() {
+	if d.resetPin == nil {
+		return
+	}
+	d.resetPin.High()
+	time.Sleep(10 * time.Millisecond)
+	d.resetPin.Low()
+	time.Sleep(10 * time.Millisecond)
+	d.resetPin.High()
+	time.Sleep(10 * time.Millisecond)
+}

bno08x/bno08x_i2c.go

@@ -0,0 +1,173 @@
+package bno08x
+
+import (
+	"time"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/pin"
+)
+
+// I2CConfig holds I2C-specific configuration options.
+type I2CConfig struct {
+	// Address is the I2C address (default: 0x4A).
+	Address uint16
+
+	// ResetPin is the optional hardware reset pin.
+	ResetPin pin.OutputFunc
+
+	// ReadChunk is the I2C read chunk size (default: 32 bytes).
+	ReadChunk int
+}
+
+const (
+	// DefaultAddress is the default I2C address.
+	DefaultAddress = 0x4A
+)
+
+// NewI2C creates a new BNO08x device using I2C communication.
+func NewI2C(bus drivers.I2C) *Device {
+	return &Device{
+		bus: &I2CBus{
+			wire:      bus,
+			address:   DefaultAddress,
+			readChunk: i2cDefaultChunk,
+		},
+	}
+}
+
+// I2CBus implements the Buser interface for I2C communication.
+type I2CBus struct {
+	wire      drivers.I2C
+	address   uint16
+	readChunk int
+	scratch   []byte
+	header    [shtpHeaderLength]byte
+}
+
+// configure sets up the I2C bus with the specified address and chunk size.
+func (b *I2CBus) configure(address uint16, readChunk int) error {
+	if address != 0 {
+		b.address = address
+	}
+	if readChunk > 0 {
+		b.readChunk = readChunk
+	}
+
+	chunk := b.readChunk
+	if chunk < shtpHeaderLength {
+		chunk = shtpHeaderLength
+	}
+	b.scratch = make([]byte, chunk)
+
+	return nil
+}
+
+// read reads data from the I2C bus.
+func (b *I2CBus) read(target []byte) (int, uint32, error) {
+	// Read SHTP header (4 bytes) to get packet length
+	// Use pre-allocated header buffer to avoid allocations
+	err := b.wire.Tx(b.address, nil, b.header[:])
+	if err != nil {
+		return 0, 0, err
+	}
+
+	// Parse packet length from header
+	packetLen := uint16(b.header[0]) | (uint16(b.header[1]) << 8)
+
+	// Check if continuation bit is set (0x8000)
+	// This means no data is available yet
+	if packetLen&continueMask != 0 {
+		return 0, 0, nil
+	}
+
+	// No continuation bit, check for actual data
+	if packetLen == 0 {
+		return 0, 0, nil
+	}
+
+	if int(packetLen) > len(target) {
+		return 0, 0, errBufferTooSmall
+	}
+
+	// Now read the full packet in chunks, re-reading the header in first chunk
+	// This follows Arduino's approach: initial header read is just to get size,
+	// actual packet data (including header) is read in the loop
+	cargoRemaining := int(packetLen)
+	offset := 0
+	firstRead := true
+
+	for cargoRemaining > 0 {
+		var request int
+		if firstRead {
+			// First read: get the full packet including header (up to chunkSize)
+			request = b.readChunk
+			if request > cargoRemaining {
+				request = cargoRemaining
+			}
+		} else {
+			// Subsequent reads: each chunk has a 4-byte header we need to skip
+			request = b.readChunk
+			if request > cargoRemaining+shtpHeaderLength {
+				request = cargoRemaining + shtpHeaderLength
+			}
+		}
+
+		// Ensure scratch buffer is large enough
+		if request > len(b.scratch) {
+			b.scratch = make([]byte, request)
+		}
+		buf := b.scratch[:request]
+
+		// Read chunk
+		err = b.wire.Tx(b.address, nil, buf)
+		if err != nil {
+			return 0, 0, err
+		}
+
+		var cargoRead int
+		if firstRead {
+			// First read: copy everything including header
+			cargoRead = request
+			copy(target[offset:], buf[:cargoRead])
+			firstRead = false
+		} else {
+			// Subsequent reads: skip the 4-byte header
+			cargoRead = request - shtpHeaderLength
+			copy(target[offset:], buf[shtpHeaderLength:shtpHeaderLength+cargoRead])
+		}
+
+		offset += cargoRead
+		cargoRemaining -= cargoRead
+	}
+
+	// Extract timestamp from the header in the target buffer
+	timestamp := uint32(target[2]) | (uint32(target[3]) << 8)
+
+	return int(packetLen), timestamp, nil
+}
+
+// write sends data over the I2C bus.
+func (b *I2CBus) write(data []byte) error {
+	return b.wire.Tx(b.address, data, nil)
+}
+
+// softReset sends a soft reset command via I2C.
+func (b *I2CBus) softReset() error {
+	// Send soft reset packet via I2C as per Adafruit implementation
+	// Format: [length_low, length_high, channel, sequence, command]
+	// This is: 5 bytes total, channel 1 (executable), command 1 (reset)
+	softResetPacket := []byte{5, 0, 1, 0, 1}
+
+	// Try up to 5 times
+	var err error
+	for i := 0; i < 5; i++ {
+		err = b.wire.Tx(b.address, softResetPacket, nil)
+		if err == nil {
+			// Success - wait for sensor to process reset
+			time.Sleep(300 * time.Millisecond)
+			return nil
+		}
+		time.Sleep(30 * time.Millisecond)
+	}
+	return err
+}

bno08x/constants.go

@@ -0,0 +1,179 @@
+package bno08x
+
+// I2C and protocol constants
+const (
+	shtpHeaderLength = 4
+	maxTransferOut   = 256
+	maxTransferIn    = 384
+
+	i2cDefaultChunk = 32
+	continueMask    = 0x8000
+)
+
+// SHTP channel numbers
+const (
+	channelCommand      = 0
+	channelExecutable   = 1
+	channelControl      = 2
+	channelSensorReport = 3
+	channelWakeReport   = 4
+	channelGyroRV       = 5
+)
+
+// SH-2 report IDs
+const (
+	reportProdIDReq      = 0xF9
+	reportProdIDResp     = 0xF8
+	reportSetFeature     = 0xFD
+	reportGetFeature     = 0xFE
+	reportGetFeatureResp = 0xFC
+	reportCommandReq     = 0xF2
+	reportCommandResp    = 0xF1
+	reportFRSWriteReq    = 0xF7
+	reportFRSWriteData   = 0xF6
+	reportFRSReadReq     = 0xF4
+	reportFRSReadResp    = 0xF3
+	reportBaseTimestamp  = 0xFB
+	reportTimestampReuse = 0xFA
+	reportForceFlush     = 0xF0
+	reportFlushCompleted = 0xEF
+	reportResetReq       = 0xF1
+	reportResetResp      = 0xF0
+)
+
+// SH-2 commands
+const (
+	cmdErrors         = 0x01
+	cmdCounts         = 0x02
+	cmdTare           = 0x03
+	cmdInitialize     = 0x04
+	cmdFRS            = 0x05
+	cmdDCD            = 0x06
+	cmdMECal          = 0x07
+	cmdProdIDReq      = 0x07
+	cmdDCDSave        = 0x09
+	cmdGetOscType     = 0x0A
+	cmdClearDCDReset  = 0x0B
+	cmdCal            = 0x0C
+	cmdBootloader     = 0x0D
+	cmdInteractiveZRO = 0x0E
+
+	// Command parameters
+	initSystem      = 0x01
+	initUnsolicited = 0x80
+
+	countsClearCounts = 0x01
+	countsGetCounts   = 0x00
+
+	tareTareNow          = 0x00
+	tarePersist          = 0x01
+	tareSetReorientation = 0x02
+
+	calStart  = 0x00
+	calFinish = 0x01
+
+	commandParamCount  = 9
+	responseValueCount = 11
+)
+
+// Feature report flags
+const (
+	featChangeSensitivityRelative = 0x01
+	featChangeSensitivityEnabled  = 0x02
+	featWakeEnabled               = 0x04
+	featAlwaysOnEnabled           = 0x08
+)
+
+// Scaling factors for sensor data
+// These are derived from the Q-point encoding in the SH-2 specification
+const (
+	scaleQuat        = 1.0 / 16384.0   // Q14
+	scaleAccel       = 1.0 / 256.0     // Q8
+	scaleGyro        = 1.0 / 512.0     // Q9
+	scaleMag         = 1.0 / 16.0      // Q4
+	scaleAccuracy    = 1.0 / 4096.0    // Q12
+	scalePressure    = 1.0 / 1048576.0 // Q20
+	scaleLight       = 1.0 / 256.0     // Q8
+	scaleHumidity    = 1.0 / 256.0     // Q8
+	scaleProximity   = 1.0 / 16.0      // Q4
+	scaleTemperature = 1.0 / 128.0     // Q7
+	scaleAngle       = 1.0 / 16.0      // Q4
+	scaleHeartRate   = 1.0 / 16.0      // Q4
+)
+
+// Activity classifier codes (extended beyond standard SH-2)
+const (
+	ActivityUnknown     = 0
+	ActivityInVehicle   = 1
+	ActivityOnBicycle   = 2
+	ActivityOnFoot      = 3
+	ActivityStill       = 4
+	ActivityTilting     = 5
+	ActivityWalking     = 6
+	ActivityRunning     = 7
+	ActivityOnStairs    = 8
+	ActivityOptionCount = 9
+)
+
+// Stability classifier values
+const (
+	StabilityUnknown    = 0
+	StabilityOnTable    = 1
+	StabilityStationary = 2
+	StabilityStable     = 3
+	StabilityMotion     = 4
+)
+
+// Tap detector flags
+const (
+	TapX      = 0x01 // 1 - X axis tapped
+	TapXPos   = 0x02 // 2 - X positive direction
+	TapY      = 0x04 // 4 - Y axis tapped
+	TapYPos   = 0x08 // 8 - Y positive direction
+	TapZ      = 0x10 // 16 - Z axis tapped
+	TapZPos   = 0x20 // 32 - Z positive direction
+	TapDouble = 0x40 // 64 - Double tap occurred
+)
+
+// GUID values for SHTP
+const (
+	guidSHTP       = 0
+	guidExecutable = 1
+	guidSensorHub  = 2
+)
+
+// Advertisement tags
+const (
+	tagNull                = 0
+	tagGUID                = 1
+	tagMaxCargoHeaderWrite = 2
+	tagMaxCargoHeaderRead  = 3
+	tagMaxTransferWrite    = 4
+	tagMaxTransferRead     = 5
+	tagNormalChannel       = 6
+	tagWakeChannel         = 7
+	tagAppName             = 8
+	tagChannelName         = 9
+	tagAdvCount            = 10
+	tagAppSpecific         = 0x80
+	tagSH2Version          = 0x80
+	tagSH2ReportLengths    = 0x81
+)
+
+// Timeouts
+const (
+	advertTimeout  = 200000 // microseconds
+	commandTimeout = 300000 // microseconds
+)
+
+// Executable device commands
+const (
+	execDeviceCmdReset = 1
+	execDeviceCmdOn    = 2
+	execDeviceCmdSleep = 3
+)
+
+// Executable device responses
+const (
+	execDeviceRespResetComplete = 1
+)

bno08x/decode.go

@@ -0,0 +1,316 @@
+package bno08x
+
+import "encoding/binary"
+
+// decodeSensor decodes a sensor report payload into a SensorValue.
+func decodeSensor(payload []byte, timestamp uint32) (SensorValue, bool) {
+	if len(payload) < 4 {
+		return SensorValue{}, false
+	}
+
+	value := SensorValue{
+		id:        SensorID(payload[0]),
+		sequence:  payload[1],
+		status:    payload[2] & 0x03,
+		delay:     payload[3],
+		timestamp: uint64(timestamp),
+	}
+
+	data := payload[4:]
+
+	switch value.id {
+	case SensorRawAccelerometer:
+		if len(data) >= 10 {
+			value.rawAccelerometer = RawVector3{
+				X:         int16(binary.LittleEndian.Uint16(data[0:])),
+				Y:         int16(binary.LittleEndian.Uint16(data[2:])),
+				Z:         int16(binary.LittleEndian.Uint16(data[4:])),
+				Timestamp: binary.LittleEndian.Uint32(data[6:]),
+			}
+		}
+
+	case SensorAccelerometer:
+		if len(data) >= 6 {
+			value.accelerometer = Vector3{
+				X: qToFloat(data[0:], scaleAccel),
+				Y: qToFloat(data[2:], scaleAccel),
+				Z: qToFloat(data[4:], scaleAccel),
+			}
+		}
+
+	case SensorLinearAcceleration:
+		if len(data) >= 6 {
+			value.linearAcceleration = Vector3{
+				X: qToFloat(data[0:], scaleAccel),
+				Y: qToFloat(data[2:], scaleAccel),
+				Z: qToFloat(data[4:], scaleAccel),
+			}
+		}
+
+	case SensorGravity:
+		if len(data) >= 6 {
+			value.gravity = Vector3{
+				X: qToFloat(data[0:], scaleAccel),
+				Y: qToFloat(data[2:], scaleAccel),
+				Z: qToFloat(data[4:], scaleAccel),
+			}
+		}
+
+	case SensorRawGyroscope:
+		if len(data) >= 12 {
+			value.rawGyroscope = RawGyroscope{
+				X:           int16(binary.LittleEndian.Uint16(data[0:])),
+				Y:           int16(binary.LittleEndian.Uint16(data[2:])),
+				Z:           int16(binary.LittleEndian.Uint16(data[4:])),
+				Temperature: int16(binary.LittleEndian.Uint16(data[6:])),
+				Timestamp:   binary.LittleEndian.Uint32(data[8:]),
+			}
+		}
+
+	case SensorGyroscope:
+		if len(data) >= 6 {
+			value.gyroscope = Vector3{
+				X: qToFloat(data[0:], scaleGyro),
+				Y: qToFloat(data[2:], scaleGyro),
+				Z: qToFloat(data[4:], scaleGyro),
+			}
+		}
+
+	case SensorGyroscopeUncalibrated:
+		if len(data) >= 12 {
+			value.gyroscopeUncal = GyroscopeUncalibrated{
+				X:     qToFloat(data[0:], scaleGyro),
+				Y:     qToFloat(data[2:], scaleGyro),
+				Z:     qToFloat(data[4:], scaleGyro),
+				BiasX: qToFloat(data[6:], scaleGyro),
+				BiasY: qToFloat(data[8:], scaleGyro),
+				BiasZ: qToFloat(data[10:], scaleGyro),
+			}
+		}
+
+	case SensorRawMagnetometer:
+		if len(data) >= 10 {
+			value.rawMagnetometer = RawVector3{
+				X:         int16(binary.LittleEndian.Uint16(data[0:])),
+				Y:         int16(binary.LittleEndian.Uint16(data[2:])),
+				Z:         int16(binary.LittleEndian.Uint16(data[4:])),
+				Timestamp: binary.LittleEndian.Uint32(data[6:]),
+			}
+		}
+
+	case SensorMagneticField:
+		if len(data) >= 6 {
+			value.magneticField = Vector3{
+				X: qToFloat(data[0:], scaleMag),
+				Y: qToFloat(data[2:], scaleMag),
+				Z: qToFloat(data[4:], scaleMag),
+			}
+		}
+
+	case SensorMagneticFieldUncalibrated:
+		if len(data) >= 12 {
+			value.magneticFieldUncal = MagneticFieldUncalibrated{
+				X:     qToFloat(data[0:], scaleMag),
+				Y:     qToFloat(data[2:], scaleMag),
+				Z:     qToFloat(data[4:], scaleMag),
+				BiasX: qToFloat(data[6:], scaleMag),
+				BiasY: qToFloat(data[8:], scaleMag),
+				BiasZ: qToFloat(data[10:], scaleMag),
+			}
+		}
+
+	case SensorRotationVector:
+		if len(data) >= 10 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+			value.quaternionAccuracy = qToFloat(data[8:], scaleAccuracy)
+		}
+
+	case SensorGameRotationVector:
+		if len(data) >= 8 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+		}
+
+	case SensorGeomagneticRotationVector:
+		if len(data) >= 10 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+			value.quaternionAccuracy = qToFloat(data[8:], scaleAccuracy)
+		}
+
+	case SensorARVRStabilizedRV:
+		if len(data) >= 10 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+			value.quaternionAccuracy = qToFloat(data[8:], scaleAccuracy)
+		}
+
+	case SensorARVRStabilizedGRV:
+		if len(data) >= 8 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+		}
+
+	case SensorGyroIntegratedRV:
+		if len(data) >= 10 {
+			value.quaternion = Quaternion{
+				I:    qToFloat(data[0:], scaleQuat),
+				J:    qToFloat(data[2:], scaleQuat),
+				K:    qToFloat(data[4:], scaleQuat),
+				Real: qToFloat(data[6:], scaleQuat),
+			}
+			// Angular velocity X at data[8:10]
+		}
+
+	case SensorPressure:
+		if len(data) >= 4 {
+			value.pressure = float32(int32(binary.LittleEndian.Uint32(data[0:]))) * scalePressure
+		}
+
+	case SensorAmbientLight:
+		if len(data) >= 4 {
+			value.ambientLight = float32(int32(binary.LittleEndian.Uint32(data[0:]))) * scaleLight
+		}
+
+	case SensorHumidity:
+		if len(data) >= 2 {
+			value.humidity = qToFloat(data[0:], scaleHumidity)
+		}
+
+	case SensorProximity:
+		if len(data) >= 2 {
+			value.proximity = qToFloat(data[0:], scaleProximity)
+		}
+
+	case SensorTemperature:
+		if len(data) >= 2 {
+			value.temperature = qToFloat(data[0:], scaleTemperature)
+		}
+
+	case SensorTapDetector:
+		if len(data) >= 1 {
+			value.tapDetector = TapDetector{
+				Flags: data[0],
+			}
+		}
+
+	case SensorStepDetector:
+		if len(data) >= 4 {
+			value.stepDetector = StepDetector{
+				Latency: binary.LittleEndian.Uint32(data[0:]),
+			}
+		}
+
+	case SensorStepCounter:
+		if len(data) >= 8 {
+			value.stepCounter = StepCounter{
+				Count:   uint16(binary.LittleEndian.Uint32(data[4:8])),
+				Latency: binary.LittleEndian.Uint32(data[0:4]),
+			}
+		}
+
+	case SensorSignificantMotion:
+		if len(data) >= 2 {
+			value.significantMotion = SignificantMotion{
+				Motion: binary.LittleEndian.Uint16(data[0:]),
+			}
+		}
+
+	case SensorStabilityClassifier:
+		if len(data) >= 1 {
+			value.stabilityClassifier = StabilityClassifier{
+				Classification: data[0],
+			}
+		}
+
+	case SensorStabilityDetector:
+		if len(data) >= 1 {
+			value.stabilityDetector = data[0]
+		}
+
+	case SensorShakeDetector:
+		if len(data) >= 2 {
+			value.shakeDetector = ShakeDetector{
+				Shake: binary.LittleEndian.Uint16(data[0:]),
+			}
+		}
+
+	case SensorFlipDetector:
+		if len(data) >= 2 {
+			value.flipDetector = binary.LittleEndian.Uint16(data[0:2])
+		}
+
+	case SensorPickupDetector:
+		if len(data) >= 2 {
+			// Pickup detected at data[0:2]
+		}
+
+	case SensorPersonalActivityClassifier:
+		if len(data) >= 16 {
+			value.personalActivityClassifier = PersonalActivityClassifier{
+				Page:            data[0],
+				MostLikelyState: data[1],
+				EndOfPage:       data[15],
+			}
+			for i := 0; i < 10 && i+2 < len(data); i++ {
+				value.personalActivityClassifier.Confidence[i] = data[2+i]
+			}
+		}
+
+	case SensorSleepDetector:
+		if len(data) >= 1 {
+			value.sleepDetector = data[0]
+		}
+
+	case SensorTiltDetector:
+		if len(data) >= 1 {
+			value.tiltDetector = data[0]
+		}
+
+	case SensorPocketDetector:
+		if len(data) >= 1 {
+			value.pocketDetector = data[0]
+		}
+
+	case SensorCircleDetector:
+		if len(data) >= 1 {
+			value.circleDetector = data[0]
+		}
+
+	case SensorHeartRateMonitor:
+		if len(data) >= 2 {
+			value.heartRateMonitor = binary.LittleEndian.Uint16(data[0:])
+		}
+	}
+
+	return value, true
+}
+
+// qToFloat converts a Q-point fixed-point value to float32.
+func qToFloat(data []byte, scale float32) float32 {
+	if len(data) < 2 {
+		return 0
+	}
+	return float32(int16(binary.LittleEndian.Uint16(data))) * scale
+}

bno08x/hal.go

@@ -0,0 +1,43 @@
+package bno08x
+
+import (
+	"time"
+)
+
+// hal implements the hardware abstraction layer for bus communication.
+type hal struct {
+	device *Device
+}
+
+func newHAL(dev *Device) *hal {
+	return &hal{
+		device: dev,
+	}
+}
+
+func (h *hal) open() error {
+	// HAL is now open and ready for communication
+	// Soft reset will be sent after handlers are registered
+	return nil
+}
+
+func (h *hal) close() {}
+
+func (h *hal) read(target []byte) (int, uint32, error) {
+	return h.device.bus.read(target)
+}
+
+func (h *hal) write(frame []byte) (int, error) {
+	if len(frame) > maxTransferOut {
+		return 0, errFrameTooLarge
+	}
+	err := h.device.bus.write(frame)
+	if err != nil {
+		return 0, err
+	}
+	return len(frame), nil
+}
+
+func (h *hal) getTimeUs() uint32 {
+	return uint32(time.Now().UnixNano() / 1000)
+}

bno08x/sh2.go

@@ -0,0 +1,387 @@
+// SH-2 specification found at https://www.ceva-ip.com/wp-content/uploads/SH-2-Reference-Manual.pdf
+
+package bno08x
+
+import (
+	"encoding/binary"
+	"time"
+)
+
+// getReportLen returns the length in bytes of a sensor report given its ID.
+// Returns 0 for unknown report IDs.
+func getReportLen(reportID byte) int {
+	switch reportID {
+	case 0xF1: // FLUSH_COMPLETED
+		return 6
+	case 0xFA: // TIMESTAMP_REBASE
+		return 5
+	case 0xFB: // BASE_TIMESTAMP_REF
+		return 5
+	case 0xFC: // GET_FEATURE_RESP
+		return 17
+	case 0x01: // Accelerometer (calibrated)
+		return 10
+	case 0x02: // Gyroscope (calibrated)
+		return 10
+	case 0x03: // Magnetic field (calibrated)
+		return 10
+	case 0x04: // Linear acceleration
+		return 10
+	case 0x05: // Rotation vector
+		return 14
+	case 0x06: // Gravity
+		return 10
+	case 0x07: // Gyroscope uncalibrated
+		return 16
+	case 0x08: // Game rotation vector
+		return 12
+	case 0x09: // Geomagnetic rotation vector
+		return 14
+	case 0x0A: // Pressure
+		return 10
+	case 0x0B: // Ambient light
+		return 10
+	case 0x0C: // Humidity
+		return 10
+	case 0x0D: // Proximity
+		return 10
+	case 0x0E: // Temperature
+		return 10
+	case 0x0F: // Magnetic field uncalibrated
+		return 16
+	case 0x10: // Tap detector
+		return 5
+	case 0x11: // Step counter
+		return 12
+	case 0x12: // Significant motion
+		return 6
+	case 0x13: // Stability classifier
+		return 5
+	case 0x14: // Raw accelerometer
+		return 16
+	case 0x15: // Raw gyroscope
+		return 16
+	case 0x16: // Raw magnetometer
+		return 16
+	case 0x18: // Step detector
+		return 8
+	case 0x19: // Shake detector
+		return 6
+	case 0x1A: // Flip detector
+		return 6
+	case 0x1B: // Pickup detector
+		return 6
+	case 0x1C: // Stability detector
+		return 6
+	case 0x1E: // Personal activity classifier
+		return 16
+	default:
+		// For most sensor reports, they are typically 10-16 bytes
+		// If we don't know the exact length, return a safe default
+		// that covers most cases (the handler will bounds-check)
+		if reportID < 0xF0 {
+			return 10 // Most sensor reports are at least this long
+		}
+		return 0
+	}
+}
+
+// sh2Protocol implements the Sensor Hub 2 (SH-2) application protocol.
+type sh2Protocol struct {
+	device               *Device
+	transport            *shtp
+	cmdSeq               uint8
+	waiting              bool
+	lastCmd              uint8
+	pendingConfigRequest bool
+	pendingConfigSensor  SensorID
+	receivedConfig       SensorConfig
+	configReady          bool
+	configBuf            [17]byte                    // Reusable buffer for setSensorConfig
+	commandBuf           [3 + commandParamCount]byte // Reusable buffer for sendCommand
+}
+
+func newSH2Protocol(device *Device) *sh2Protocol {
+	proto := &sh2Protocol{
+		device:    device,
+		transport: device.shtp,
+	}
+
+	// Register handlers for each channel
+	device.shtp.register(channelControl, proto.handleControl)
+	device.shtp.register(channelSensorReport, proto.handleSensor)
+	device.shtp.register(channelWakeReport, proto.handleSensor)
+	device.shtp.register(channelGyroRV, proto.handleSensor)
+	device.shtp.register(channelExecutable, proto.handleExecutable)
+
+	return proto
+}
+
+// softReset sends a software reset command to the sensor.
+func (s *sh2Protocol) softReset() error {
+	payload := []byte{execDeviceCmdReset}
+	return s.transport.send(channelExecutable, payload)
+}
+
+// initialize sends the initialize command to the sensor.
+func (s *sh2Protocol) initialize() error {
+	return s.sendCommand(cmdInitialize, []byte{initSystem})
+}
+
+// requestProductIDs requests product identification information.
+func (s *sh2Protocol) requestProductIDs() error {
+	payload := []byte{reportProdIDReq, 0x00}
+	return s.transport.send(channelControl, payload)
+}
+
+// enableReport enables a sensor report at the specified interval.
+func (s *sh2Protocol) enableReport(id SensorID, intervalUs uint32) error {
+	config := SensorConfig{
+		ReportInterval: intervalUs,
+	}
+	return s.setSensorConfig(id, config)
+}
+
+// getSensorConfig retrieves the configuration for a sensor.
+// This method sends a GET_FEATURE request and waits for the response
+// by polling the device. It will timeout after approximately 1 second.
+func (s *sh2Protocol) getSensorConfig(id SensorID) (SensorConfig, error) {
+	// Mark that we're waiting for a config response
+	s.pendingConfigRequest = true
+	s.pendingConfigSensor = id
+	s.configReady = false
+
+	payload := []byte{reportGetFeature, byte(id)}
+	err := s.transport.send(channelControl, payload)
+	if err != nil {
+		s.pendingConfigRequest = false
+		return SensorConfig{}, err
+	}
+
+	// Poll for response with timeout
+	maxAttempts := 100 // ~1 second with 10ms delays
+	for i := 0; i < maxAttempts; i++ {
+		// Service the device to process incoming messages
+		s.device.shtp.poll()
+
+		if s.configReady {
+			s.pendingConfigRequest = false
+			s.configReady = false
+			return s.receivedConfig, nil
+		}
+
+		// Small delay between polls
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	s.pendingConfigRequest = false
+	return SensorConfig{}, errTimeout
+}
+
+// setSensorConfig configures a sensor.
+func (s *sh2Protocol) setSensorConfig(id SensorID, config SensorConfig) error {
+	// Use pre-allocated buffer to avoid allocations
+	payload := s.configBuf[:]
+	payload[0] = reportSetFeature
+	payload[1] = byte(id)
+
+	// Build feature flags
+	var flags uint8
+	if config.ChangeSensitivityEnabled {
+		flags |= featChangeSensitivityEnabled
+	}
+	if config.ChangeSensitivityRelative {
+		flags |= featChangeSensitivityRelative
+	}
+	if config.WakeupEnabled {
+		flags |= featWakeEnabled
+	}
+	if config.AlwaysOnEnabled {
+		flags |= featAlwaysOnEnabled
+	}
+	payload[2] = flags
+
+	binary.LittleEndian.PutUint16(payload[3:5], config.ChangeSensitivity)
+	binary.LittleEndian.PutUint32(payload[5:9], config.ReportInterval)
+	binary.LittleEndian.PutUint32(payload[9:13], config.BatchInterval)
+	binary.LittleEndian.PutUint32(payload[13:17], config.SensorSpecific)
+
+	return s.transport.send(channelControl, payload)
+}
+
+// sendCommand sends a command with parameters to the sensor.
+func (s *sh2Protocol) sendCommand(command byte, params []byte) error {
+	// Use pre-allocated buffer to avoid allocations
+	payload := s.commandBuf[:]
+	payload[0] = reportCommandReq
+	payload[1] = s.cmdSeq
+	payload[2] = command
+	s.cmdSeq++
+	s.lastCmd = command
+	s.waiting = true
+
+	for i := 0; i < commandParamCount && i < len(params); i++ {
+		payload[3+i] = params[i]
+	}
+
+	return s.transport.send(channelControl, payload[:3+commandParamCount])
+}
+
+// handleControl processes control channel messages.
+func (s *sh2Protocol) handleControl(payload []byte, timestamp uint32) {
+	if len(payload) == 0 {
+		return
+	}
+
+	reportID := payload[0]
+
+	switch reportID {
+	case reportProdIDResp:
+		s.handleProdID(payload, timestamp)
+	case reportCommandResp:
+		s.handleCommandResp(payload, timestamp)
+	case reportGetFeatureResp:
+		s.handleGetFeatureResp(payload, timestamp)
+	case reportFRSReadResp:
+		// FRS (Flash Record System) read response
+		// Not implemented in basic version
+	}
+}
+
+// handleProdID processes product ID responses.
+func (s *sh2Protocol) handleProdID(payload []byte, timestamp uint32) {
+	if len(payload) < 16 {
+		return
+	}
+
+	entry := ProductID{
+		ResetCause:   payload[1],
+		VersionMajor: payload[2],
+		VersionMinor: payload[3],
+		PartNumber:   binary.LittleEndian.Uint32(payload[4:8]),
+		BuildNumber:  binary.LittleEndian.Uint32(payload[8:12]),
+		VersionPatch: binary.LittleEndian.Uint16(payload[12:14]),
+		Reserved0:    payload[14],
+		Reserved1:    payload[15],
+	}
+
+	// Store in first slot
+	s.device.productIDs.Entries[0] = entry
+	s.device.productIDs.NumEntries = 1
+}
+
+// handleCommandResp processes command responses.
+func (s *sh2Protocol) handleCommandResp(payload []byte, timestamp uint32) {
+	if len(payload) < 16 {
+		return
+	}
+
+	// seq := payload[1]
+	command := payload[2]
+	// commandSeq := payload[3]
+	// respSeq := payload[4]
+
+	// Check if this response is for our command
+	if s.waiting && command == s.lastCmd {
+		s.waiting = false
+		// Status is in payload[6]
+		// For now, we just acknowledge receipt
+	}
+}
+
+// handleGetFeatureResp processes get feature responses.
+func (s *sh2Protocol) handleGetFeatureResp(payload []byte, timestamp uint32) {
+	if len(payload) < 17 {
+		return
+	}
+
+	// Parse the response
+	sensorID := SensorID(payload[1])
+	flags := payload[2]
+	changeSensitivity := binary.LittleEndian.Uint16(payload[3:5])
+	reportInterval := binary.LittleEndian.Uint32(payload[5:9])
+	batchInterval := binary.LittleEndian.Uint32(payload[9:13])
+	sensorSpecific := binary.LittleEndian.Uint32(payload[13:17])
+
+	// If we're waiting for this sensor's config, store it
+	if s.pendingConfigRequest && s.pendingConfigSensor == sensorID {
+		s.receivedConfig = SensorConfig{
+			ChangeSensitivityEnabled:  flags&featChangeSensitivityEnabled != 0,
+			ChangeSensitivityRelative: flags&featChangeSensitivityRelative != 0,
+			WakeupEnabled:             flags&featWakeEnabled != 0,
+			AlwaysOnEnabled:           flags&featAlwaysOnEnabled != 0,
+			ChangeSensitivity:         changeSensitivity,
+			ReportInterval:            reportInterval,
+			BatchInterval:             batchInterval,
+			SensorSpecific:            sensorSpecific,
+		}
+		s.configReady = true
+	}
+}
+
+// handleSensor processes sensor report messages.
+// The payload can contain multiple sensor reports batched together.
+func (s *sh2Protocol) handleSensor(payload []byte, timestamp uint32) {
+	cursor := 0
+	var referenceDelta uint32
+
+	for cursor < len(payload) {
+		if cursor >= len(payload) {
+			break
+		}
+
+		reportID := payload[cursor]
+		reportLen := getReportLen(reportID)
+
+		if reportLen == 0 {
+			// Unknown report ID
+			break
+		}
+
+		if cursor+reportLen > len(payload) {
+			// Not enough data for this report
+			break
+		}
+
+		// Handle special report types
+		switch reportID {
+		case 0xFB: // SENSORHUB_BASE_TIMESTAMP_REF
+			if reportLen >= 5 {
+				// Extract timebase (little-endian uint32)
+				timebase := binary.LittleEndian.Uint32(payload[cursor+1 : cursor+5])
+				referenceDelta = -timebase // Store negative for delta calculation
+			}
+
+		case 0xFA: // SENSORHUB_TIMESTAMP_REBASE
+			if reportLen >= 5 {
+				timebase := binary.LittleEndian.Uint32(payload[cursor+1 : cursor+5])
+				referenceDelta += timebase
+			}
+
+		case 0xF1: // SENSORHUB_FLUSH_COMPLETED
+			// Route to control handler
+			s.handleControl(payload[cursor:cursor+reportLen], timestamp)
+
+		default:
+			// Regular sensor report
+			value, ok := decodeSensor(payload[cursor:cursor+reportLen], timestamp)
+			if ok {
+				s.device.enqueue(value)
+			}
+		}
+
+		cursor += reportLen
+	}
+} // handleExecutable processes executable channel messages.
+func (s *sh2Protocol) handleExecutable(payload []byte, timestamp uint32) {
+	if len(payload) == 0 {
+		return
+	}
+
+	reportID := payload[0]
+
+	switch reportID {
+	case execDeviceRespResetComplete:
+		s.device.lastReset = true
+	}
+}

bno08x/shtp.go

@@ -0,0 +1,83 @@
+// SHTP specification found at https://www.ceva-ip.com/wp-content/uploads/SH-2-SHTP-Reference-Manual.pdf
+
+package bno08x
+
+import "encoding/binary"
+
+// shtpHandler is a callback for handling SHTP channel data.
+type shtpHandler func(payload []byte, timestamp uint32)
+
+// shtp implements the Sensor Hub Transport Protocol layer.
+type shtp struct {
+	hal      *hal
+	handlers map[uint8]shtpHandler
+	seq      [8]uint8
+	rx       [maxTransferIn]byte  // Reusable receive buffer
+	tx       [maxTransferOut]byte // Reusable transmit buffer
+}
+
+func newSHTP(hal *hal) *shtp {
+	return &shtp{
+		hal:      hal,
+		handlers: make(map[uint8]shtpHandler),
+	}
+}
+
+// register registers a handler for a specific SHTP channel.
+func (s *shtp) register(channel uint8, handler shtpHandler) {
+	if handler == nil {
+		delete(s.handlers, channel)
+		return
+	}
+	s.handlers[channel] = handler
+}
+
+// send transmits a payload on the specified channel.
+func (s *shtp) send(channel uint8, payload []byte) error {
+	total := len(payload) + shtpHeaderLength
+	if total > maxTransferOut {
+		return errFrameTooLarge
+	}
+
+	// Use pre-allocated transmit buffer to avoid allocations
+	frame := s.tx[:total]
+	binary.LittleEndian.PutUint16(frame[0:2], uint16(total))
+	frame[2] = channel
+	frame[3] = s.seq[channel]
+	s.seq[channel]++
+	copy(frame[shtpHeaderLength:], payload)
+
+	_, err := s.hal.write(frame)
+	return err
+}
+
+// poll checks for and processes incoming SHTP packets.
+// Returns true if a packet was processed, false if no data available.
+func (s *shtp) poll() (bool, error) {
+	n, timestamp, err := s.hal.read(s.rx[:])
+	if err != nil {
+		return false, err
+	}
+	if n == 0 {
+		return false, nil
+	}
+
+	packet := s.rx[:n]
+	length := int(binary.LittleEndian.Uint16(packet[0:2]) & ^uint16(continueMask))
+	if length > n {
+		length = n
+	}
+	if length < shtpHeaderLength {
+		return false, nil
+	}
+
+	channel := packet[2]
+	// seq := packet[3] // sequence number, not currently validated
+	payload := packet[shtpHeaderLength:length]
+
+	if handler := s.handlers[channel]; handler != nil {
+		handler(payload, timestamp)
+	}
+
+	return true, nil
+}

bno08x/types.go

@@ -0,0 +1,572 @@
+package bno08x
+
+// SensorID identifies a specific sensor type.
+type SensorID uint8
+
+// Sensor IDs as defined in the SH-2 specification.
+const (
+	SensorRawAccelerometer           SensorID = 0x14
+	SensorAccelerometer              SensorID = 0x01
+	SensorLinearAcceleration         SensorID = 0x04
+	SensorGravity                    SensorID = 0x06
+	SensorRawGyroscope               SensorID = 0x15
+	SensorGyroscope                  SensorID = 0x02
+	SensorGyroscopeUncalibrated      SensorID = 0x07
+	SensorRawMagnetometer            SensorID = 0x16
+	SensorMagneticField              SensorID = 0x03
+	SensorMagneticFieldUncalibrated  SensorID = 0x0F
+	SensorRotationVector             SensorID = 0x05
+	SensorGameRotationVector         SensorID = 0x08
+	SensorGeomagneticRotationVector  SensorID = 0x09
+	SensorPressure                   SensorID = 0x0A
+	SensorAmbientLight               SensorID = 0x0B
+	SensorHumidity                   SensorID = 0x0C
+	SensorProximity                  SensorID = 0x0D
+	SensorTemperature                SensorID = 0x0E
+	SensorReserved                   SensorID = 0x17
+	SensorTapDetector                SensorID = 0x10
+	SensorStepDetector               SensorID = 0x18
+	SensorStepCounter                SensorID = 0x11
+	SensorSignificantMotion          SensorID = 0x12
+	SensorStabilityClassifier        SensorID = 0x13
+	SensorShakeDetector              SensorID = 0x19
+	SensorFlipDetector               SensorID = 0x1A
+	SensorPickupDetector             SensorID = 0x1B
+	SensorStabilityDetector          SensorID = 0x1C
+	SensorPersonalActivityClassifier SensorID = 0x1E
+	SensorSleepDetector              SensorID = 0x1F
+	SensorTiltDetector               SensorID = 0x20
+	SensorPocketDetector             SensorID = 0x21
+	SensorCircleDetector             SensorID = 0x22
+	SensorHeartRateMonitor           SensorID = 0x23
+	SensorARVRStabilizedRV           SensorID = 0x28
+	SensorARVRStabilizedGRV          SensorID = 0x29
+	SensorGyroIntegratedRV           SensorID = 0x2A
+	SensorIZROMotionRequest          SensorID = 0x2B
+	SensorMaxID                      SensorID = 0x2B
+)
+
+// ProductID contains firmware information from the sensor.
+type ProductID struct {
+	ResetCause   uint8
+	VersionMajor uint8
+	VersionMinor uint8
+	PartNumber   uint32
+	BuildNumber  uint32
+	VersionPatch uint16
+	Reserved0    uint8
+	Reserved1    uint8
+}
+
+// ProductIDs holds all product ID entries returned by the sensor.
+type ProductIDs struct {
+	Entries    [5]ProductID
+	NumEntries uint8
+}
+
+// Vector3 represents a 3D vector.
+type Vector3 struct {
+	X float32
+	Y float32
+	Z float32
+}
+
+// Quaternion represents a quaternion in (real, i, j, k) format.
+// Note: This maps to (w, x, y, z) convention where w=real, x=i, y=j, z=k.
+type Quaternion struct {
+	Real float32
+	I    float32
+	J    float32
+	K    float32
+}
+
+// RawVector3 contains raw ADC counts with timestamp.
+type RawVector3 struct {
+	X         int16
+	Y         int16
+	Z         int16
+	Timestamp uint32
+}
+
+// RawGyroscope contains raw gyro readings with temperature and timestamp.
+type RawGyroscope struct {
+	X           int16
+	Y           int16
+	Z           int16
+	Temperature int16
+	Timestamp   uint32
+}
+
+// GyroscopeUncalibrated contains uncalibrated gyroscope data with bias.
+type GyroscopeUncalibrated struct {
+	X     float32
+	Y     float32
+	Z     float32
+	BiasX float32
+	BiasY float32
+	BiasZ float32
+}
+
+// MagneticFieldUncalibrated contains uncalibrated magnetometer data with bias.
+type MagneticFieldUncalibrated struct {
+	X     float32
+	Y     float32
+	Z     float32
+	BiasX float32
+	BiasY float32
+	BiasZ float32
+}
+
+// TapDetector contains tap/double-tap detection flags.
+type TapDetector struct {
+	Flags uint8
+}
+
+// StepDetector contains step detection with latency.
+type StepDetector struct {
+	Latency uint32
+}
+
+// StepCounter contains step count with latency.
+type StepCounter struct {
+	Count   uint16
+	Latency uint32
+}
+
+// SignificantMotion indicates significant motion was detected.
+type SignificantMotion struct {
+	Motion uint16
+}
+
+// ActivityClassification contains activity classification data.
+type ActivityClassification struct {
+	Page            uint8
+	MostLikelyState uint8
+	Classification  [10]uint8
+	EndOfPage       uint8
+}
+
+// ShakeDetector contains shake detection data.
+type ShakeDetector struct {
+	Shake uint16
+}
+
+// StabilityClassifier contains stability classification.
+type StabilityClassifier struct {
+	Classification uint8
+}
+
+// PersonalActivityClassifier contains personal activity data.
+type PersonalActivityClassifier struct {
+	Page            uint8
+	MostLikelyState uint8
+	Confidence      [10]uint8
+	EndOfPage       uint8
+}
+
+// SensorValue contains decoded sensor data for all sensor types.
+type SensorValue struct {
+	id        SensorID
+	status    uint8
+	sequence  uint8
+	delay     uint8
+	timestamp uint64
+
+	// Orientation data (quaternions)
+	quaternion         Quaternion
+	quaternionAccuracy float32
+
+	// Linear measurements
+	accelerometer      Vector3
+	linearAcceleration Vector3
+	gravity            Vector3
+	gyroscope          Vector3
+	gyroscopeUncal     GyroscopeUncalibrated
+	magneticField      Vector3
+	magneticFieldUncal MagneticFieldUncalibrated
+
+	// Raw sensor data
+	rawAccelerometer RawVector3
+	rawGyroscope     RawGyroscope
+	rawMagnetometer  RawVector3
+
+	// Environmental sensors
+	pressure     float32 // hPa
+	ambientLight float32 // lux
+	humidity     float32 // %
+	proximity    float32 // cm
+	temperature  float32 // °C
+
+	// Activity detection
+	tapDetector                TapDetector
+	stepCounter                StepCounter
+	stepDetector               StepDetector
+	significantMotion          SignificantMotion
+	shakeDetector              ShakeDetector
+	flipDetector               uint16
+	stabilityClassifier        StabilityClassifier
+	stabilityDetector          uint8
+	activityClassifier         ActivityClassification
+	personalActivityClassifier PersonalActivityClassifier
+	sleepDetector              uint8
+	tiltDetector               uint8
+	pocketDetector             uint8
+	circleDetector             uint8
+	heartRateMonitor           uint16
+}
+
+// SensorConfig holds configuration settings for a sensor.
+type SensorConfig struct {
+	ChangeSensitivityEnabled  bool
+	ChangeSensitivityRelative bool
+	WakeupEnabled             bool
+	AlwaysOnEnabled           bool
+	ChangeSensitivity         uint16
+	ReportInterval            uint32 // microseconds
+	BatchInterval             uint32 // microseconds
+	SensorSpecific            uint32
+}
+
+// Error represents a driver error.
+type Error string
+
+func (e Error) Error() string { return string(e) }
+
+// Error constants.
+var (
+	errBufferTooSmall = Error("bno08x: buffer too small")
+	errNoEvent        = Error("bno08x: no sensor event available")
+	errTimeout        = Error("bno08x: operation timed out")
+	errFrameTooLarge  = Error("bno08x: frame exceeds maximum size")
+	errNoBus          = Error("bno08x: I2C bus not configured")
+	errInvalidParam   = Error("bno08x: invalid parameter")
+	errHubError       = Error("bno08x: sensor hub error")
+	errIO             = Error("bno08x: I/O error")
+)
+
+// Metadata accessor methods (always available for any sensor type)
+
+// ID returns the sensor ID.
+func (sv SensorValue) ID() SensorID {
+	return sv.id
+}
+
+// Status returns the sensor status flags.
+func (sv SensorValue) Status() uint8 {
+	return sv.status
+}
+
+// Sequence returns the sequence number.
+func (sv SensorValue) Sequence() uint8 {
+	return sv.sequence
+}
+
+// Delay returns the sensor delay value.
+func (sv SensorValue) Delay() uint8 {
+	return sv.delay
+}
+
+// Timestamp returns the sensor timestamp.
+func (sv SensorValue) Timestamp() uint64 {
+	return sv.timestamp
+}
+
+// Orientation data accessor methods
+
+// Quaternion returns the quaternion value for rotation vector sensors.
+// Panics if called on a sensor type that doesn't provide quaternion data.
+func (sv SensorValue) Quaternion() Quaternion {
+	switch sv.id {
+	case SensorRotationVector, SensorGameRotationVector, SensorGeomagneticRotationVector,
+		SensorARVRStabilizedRV, SensorARVRStabilizedGRV, SensorGyroIntegratedRV:
+		return sv.quaternion
+	default:
+		panic("bno08x: Quaternion() called on non-rotation sensor type")
+	}
+}
+
+// QuaternionAccuracy returns the quaternion accuracy estimate.
+// Panics if called on a sensor type that doesn't provide quaternion accuracy.
+func (sv SensorValue) QuaternionAccuracy() float32 {
+	switch sv.id {
+	case SensorRotationVector, SensorGeomagneticRotationVector, SensorARVRStabilizedRV:
+		return sv.quaternionAccuracy
+	default:
+		panic("bno08x: QuaternionAccuracy() called on sensor type without accuracy data")
+	}
+}
+
+// Linear measurement accessor methods
+
+// Accelerometer returns the accelerometer vector.
+// Panics if called on a sensor type other than SensorAccelerometer.
+func (sv SensorValue) Accelerometer() Vector3 {
+	if sv.id != SensorAccelerometer {
+		panic("bno08x: Accelerometer() called on non-accelerometer sensor type")
+	}
+	return sv.accelerometer
+}
+
+// LinearAcceleration returns the linear acceleration vector.
+// Panics if called on a sensor type other than SensorLinearAcceleration.
+func (sv SensorValue) LinearAcceleration() Vector3 {
+	if sv.id != SensorLinearAcceleration {
+		panic("bno08x: LinearAcceleration() called on wrong sensor type")
+	}
+	return sv.linearAcceleration
+}
+
+// Gravity returns the gravity vector.
+// Panics if called on a sensor type other than SensorGravity.
+func (sv SensorValue) Gravity() Vector3 {
+	if sv.id != SensorGravity {
+		panic("bno08x: Gravity() called on non-gravity sensor type")
+	}
+	return sv.gravity
+}
+
+// Gyroscope returns the gyroscope vector.
+// Panics if called on a sensor type other than SensorGyroscope.
+func (sv SensorValue) Gyroscope() Vector3 {
+	if sv.id != SensorGyroscope {
+		panic("bno08x: Gyroscope() called on non-gyroscope sensor type")
+	}
+	return sv.gyroscope
+}
+
+// GyroscopeUncal returns the uncalibrated gyroscope data.
+// Panics if called on a sensor type other than SensorGyroscopeUncalibrated.
+func (sv SensorValue) GyroscopeUncal() GyroscopeUncalibrated {
+	if sv.id != SensorGyroscopeUncalibrated {
+		panic("bno08x: GyroscopeUncal() called on wrong sensor type")
+	}
+	return sv.gyroscopeUncal
+}
+
+// MagneticField returns the magnetic field vector.
+// Panics if called on a sensor type other than SensorMagneticField.
+func (sv SensorValue) MagneticField() Vector3 {
+	if sv.id != SensorMagneticField {
+		panic("bno08x: MagneticField() called on wrong sensor type")
+	}
+	return sv.magneticField
+}
+
+// MagneticFieldUncal returns the uncalibrated magnetic field data.
+// Panics if called on a sensor type other than SensorMagneticFieldUncalibrated.
+func (sv SensorValue) MagneticFieldUncal() MagneticFieldUncalibrated {
+	if sv.id != SensorMagneticFieldUncalibrated {
+		panic("bno08x: MagneticFieldUncal() called on wrong sensor type")
+	}
+	return sv.magneticFieldUncal
+}
+
+// Raw sensor data accessor methods
+
+// RawAccelerometer returns the raw accelerometer data.
+// Panics if called on a sensor type other than SensorRawAccelerometer.
+func (sv SensorValue) RawAccelerometer() RawVector3 {
+	if sv.id != SensorRawAccelerometer {
+		panic("bno08x: RawAccelerometer() called on wrong sensor type")
+	}
+	return sv.rawAccelerometer
+}
+
+// RawGyroscope returns the raw gyroscope data.
+// Panics if called on a sensor type other than SensorRawGyroscope.
+func (sv SensorValue) RawGyroscope() RawGyroscope {
+	if sv.id != SensorRawGyroscope {
+		panic("bno08x: RawGyroscope() called on wrong sensor type")
+	}
+	return sv.rawGyroscope
+}
+
+// RawMagnetometer returns the raw magnetometer data.
+// Panics if called on a sensor type other than SensorRawMagnetometer.
+func (sv SensorValue) RawMagnetometer() RawVector3 {
+	if sv.id != SensorRawMagnetometer {
+		panic("bno08x: RawMagnetometer() called on wrong sensor type")
+	}
+	return sv.rawMagnetometer
+}
+
+// Environmental sensor accessor methods
+
+// Pressure returns the pressure reading in hPa.
+// Panics if called on a sensor type other than SensorPressure.
+func (sv SensorValue) Pressure() float32 {
+	if sv.id != SensorPressure {
+		panic("bno08x: Pressure() called on non-pressure sensor type")
+	}
+	return sv.pressure
+}
+
+// AmbientLight returns the ambient light reading in lux.
+// Panics if called on a sensor type other than SensorAmbientLight.
+func (sv SensorValue) AmbientLight() float32 {
+	if sv.id != SensorAmbientLight {
+		panic("bno08x: AmbientLight() called on wrong sensor type")
+	}
+	return sv.ambientLight
+}
+
+// Humidity returns the humidity reading in percent.
+// Panics if called on a sensor type other than SensorHumidity.
+func (sv SensorValue) Humidity() float32 {
+	if sv.id != SensorHumidity {
+		panic("bno08x: Humidity() called on non-humidity sensor type")
+	}
+	return sv.humidity
+}
+
+// Proximity returns the proximity reading in cm.
+// Panics if called on a sensor type other than SensorProximity.
+func (sv SensorValue) Proximity() float32 {
+	if sv.id != SensorProximity {
+		panic("bno08x: Proximity() called on non-proximity sensor type")
+	}
+	return sv.proximity
+}
+
+// Temperature returns the temperature reading in °C.
+// Panics if called on a sensor type other than SensorTemperature.
+func (sv SensorValue) Temperature() float32 {
+	if sv.id != SensorTemperature {
+		panic("bno08x: Temperature() called on non-temperature sensor type")
+	}
+	return sv.temperature
+}
+
+// Activity detection accessor methods
+
+// TapDetector returns the tap detector data.
+// Panics if called on a sensor type other than SensorTapDetector.
+func (sv SensorValue) TapDetector() TapDetector {
+	if sv.id != SensorTapDetector {
+		panic("bno08x: TapDetector() called on wrong sensor type")
+	}
+	return sv.tapDetector
+}
+
+// StepCounter returns the step counter value.
+// Panics if called on a sensor type other than SensorStepCounter.
+func (sv SensorValue) StepCounter() StepCounter {
+	if sv.id != SensorStepCounter {
+		panic("bno08x: StepCounter() called on wrong sensor type")
+	}
+	return sv.stepCounter
+}
+
+// StepDetector returns the step detector data.
+// Panics if called on a sensor type other than SensorStepDetector.
+func (sv SensorValue) StepDetector() StepDetector {
+	if sv.id != SensorStepDetector {
+		panic("bno08x: StepDetector() called on wrong sensor type")
+	}
+	return sv.stepDetector
+}
+
+// SignificantMotion returns the significant motion data.
+// Panics if called on a sensor type other than SensorSignificantMotion.
+func (sv SensorValue) SignificantMotion() SignificantMotion {
+	if sv.id != SensorSignificantMotion {
+		panic("bno08x: SignificantMotion() called on wrong sensor type")
+	}
+	return sv.significantMotion
+}
+
+// ShakeDetector returns the shake detector data.
+// Panics if called on a sensor type other than SensorShakeDetector.
+func (sv SensorValue) ShakeDetector() ShakeDetector {
+	if sv.id != SensorShakeDetector {
+		panic("bno08x: ShakeDetector() called on wrong sensor type")
+	}
+	return sv.shakeDetector
+}
+
+// FlipDetector returns the flip detector data.
+// Panics if called on a sensor type other than SensorFlipDetector.
+func (sv SensorValue) FlipDetector() uint16 {
+	if sv.id != SensorFlipDetector {
+		panic("bno08x: FlipDetector() called on wrong sensor type")
+	}
+	return sv.flipDetector
+}
+
+// StabilityClassifier returns the stability classifier data.
+// Panics if called on a sensor type other than SensorStabilityClassifier.
+func (sv SensorValue) StabilityClassifier() StabilityClassifier {
+	if sv.id != SensorStabilityClassifier {
+		panic("bno08x: StabilityClassifier() called on wrong sensor type")
+	}
+	return sv.stabilityClassifier
+}
+
+// StabilityDetector returns the stability detector value.
+// Panics if called on a sensor type other than SensorStabilityDetector.
+func (sv SensorValue) StabilityDetector() uint8 {
+	if sv.id != SensorStabilityDetector {
+		panic("bno08x: StabilityDetector() called on wrong sensor type")
+	}
+	return sv.stabilityDetector
+}
+
+// ActivityClassifier returns the activity classification data.
+// Note: This field appears unused in decode.go, keeping for API compatibility.
+func (sv SensorValue) ActivityClassifier() ActivityClassification {
+	return sv.activityClassifier
+}
+
+// PersonalActivityClassifier returns the personal activity classifier data.
+// Panics if called on a sensor type other than SensorPersonalActivityClassifier.
+func (sv SensorValue) PersonalActivityClassifier() PersonalActivityClassifier {
+	if sv.id != SensorPersonalActivityClassifier {
+		panic("bno08x: PersonalActivityClassifier() called on wrong sensor type")
+	}
+	return sv.personalActivityClassifier
+}
+
+// SleepDetector returns the sleep detector value.
+// Panics if called on a sensor type other than SensorSleepDetector.
+func (sv SensorValue) SleepDetector() uint8 {
+	if sv.id != SensorSleepDetector {
+		panic("bno08x: SleepDetector() called on wrong sensor type")
+	}
+	return sv.sleepDetector
+}
+
+// TiltDetector returns the tilt detector value.
+// Panics if called on a sensor type other than SensorTiltDetector.
+func (sv SensorValue) TiltDetector() uint8 {
+	if sv.id != SensorTiltDetector {
+		panic("bno08x: TiltDetector() called on wrong sensor type")
+	}
+	return sv.tiltDetector
+}
+
+// PocketDetector returns the pocket detector value.
+// Panics if called on a sensor type other than SensorPocketDetector.
+func (sv SensorValue) PocketDetector() uint8 {
+	if sv.id != SensorPocketDetector {
+		panic("bno08x: PocketDetector() called on wrong sensor type")
+	}
+	return sv.pocketDetector
+}
+
+// CircleDetector returns the circle detector value.
+// Panics if called on a sensor type other than SensorCircleDetector.
+func (sv SensorValue) CircleDetector() uint8 {
+	if sv.id != SensorCircleDetector {
+		panic("bno08x: CircleDetector() called on wrong sensor type")
+	}
+	return sv.circleDetector
+}
+
+// HeartRateMonitor returns the heart rate monitor value.
+// Panics if called on a sensor type other than SensorHeartRateMonitor.
+func (sv SensorValue) HeartRateMonitor() uint16 {
+	if sv.id != SensorHeartRateMonitor {
+		panic("bno08x: HeartRateMonitor() called on wrong sensor type")
+	}
+	return sv.heartRateMonitor
+}

buzzer/buzzer.go

@@ -2,22 +2,22 @@
 package buzzer // import "tinygo.org/x/drivers/buzzer"
 
 import (
-	"machine"
-
 	"time"
+
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 // Device wraps a GPIO connection to a buzzer.
 type Device struct {
-	pin  machine.Pin
+	pin  pin.OutputFunc
 	High bool
 	BPM  float64
 }
 
 // New returns a new buzzer driver given which pin to use
-func New(pin machine.Pin) Device {
+func New(pin pin.Output) Device {
 	return Device{
-		pin:  pin,
+		pin:  pin.Set,
 		High: false,
 		BPM:  96.0,
 	}
@@ -25,14 +25,14 @@ func New(pin machine.Pin) Device {
 
 // On sets the buzzer to a high state.
 func (l *Device) On() (err error) {
-	l.pin.Set(true)
+	l.pin.High()
 	l.High = true
 	return
 }
 
 // Off sets the buzzer to a low state.
 func (l *Device) Off() (err error) {
-	l.pin.Set(false)
+	l.pin.Low()
 	l.High = false
 	return
 }

ds3231/ds3231.go

@@ -5,10 +5,12 @@
 package ds3231 // import "tinygo.org/x/drivers/ds3231"
 
 import (
+	"encoding/binary"
+	"errors"
 	"time"
 
 	"tinygo.org/x/drivers"
-	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/regmap"
 )
 
 type Mode uint8
@@ -17,6 +19,7 @@ type Mode uint8
 type Device struct {
 	bus     drivers.I2C
 	Address uint16
+	d       regmap.Device8I2C
 }
 
 // New creates a new DS3231 connection. The I2C bus must already be
@@ -24,54 +27,50 @@ type Device struct {
 //
 // This function only creates the Device object, it does not touch the device.
 func New(bus drivers.I2C) Device {
-	return Device{
+	d := Device{
 		bus:     bus,
 		Address: Address,
 	}
+	d.Configure()
+	return d
 }
 
 // Configure sets up the device for communication
 func (d *Device) Configure() bool {
+	d.d.SetBus(d.bus, d.Address, binary.BigEndian)
 	return true
 }
 
 // IsTimeValid return true/false is the time in the device is valid
 func (d *Device) IsTimeValid() bool {
-	data := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_STATUS, data)
+	status, err := d.d.Read8(REG_STATUS)
 	if err != nil {
 		return false
 	}
-	return (data[0] & (1 << OSF)) == 0x00
+	return (status & (1 << OSF)) == 0x00
 }
 
 // IsRunning returns if the oscillator is running
 func (d *Device) IsRunning() bool {
-	data := []uint8{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_CONTROL, data)
+	control, err := d.d.Read8(REG_CONTROL)
 	if err != nil {
 		return false
 	}
-	return (data[0] & (1 << EOSC)) == 0x00
+	return (control & (1 << EOSC)) == 0x00
 }
 
 // SetRunning starts the internal oscillator
 func (d *Device) SetRunning(isRunning bool) error {
-	data := []uint8{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_CONTROL, data)
+	control, err := d.d.Read8(REG_CONTROL)
 	if err != nil {
 		return err
 	}
 	if isRunning {
-		data[0] &^= uint8(1 << EOSC)
+		control &^= uint8(1 << EOSC)
 	} else {
-		data[0] |= 1 << EOSC
+		control |= 1 << EOSC
 	}
-	err = legacy.WriteRegister(d.bus, uint8(d.Address), REG_CONTROL, data)
-	if err != nil {
-		return err
-	}
-	return nil
+	return d.d.Write8(REG_CONTROL, control)
 }
 
 // SetTime sets the date and time in the DS3231. The DS3231 hardware supports
@@ -86,18 +85,16 @@ func (d *Device) SetRunning(isRunning bool) error {
 // 2100 as a leap year, causing it to increment from 2100-02-28 to 2100-02-29
 // instead of 2100-03-01.
 func (d *Device) SetTime(dt time.Time) error {
-	data := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_STATUS, data)
+	status, err := d.d.Read8(REG_STATUS)
 	if err != nil {
 		return err
 	}
-	data[0] &^= 1 << OSF
-	err = legacy.WriteRegister(d.bus, uint8(d.Address), REG_STATUS, data)
-	if err != nil {
+	status &^= 1 << OSF
+	if err = d.d.Write8(REG_STATUS, status); err != nil {
 		return err
 	}
 
-	data = make([]uint8, 7)
+	data := make([]uint8, 7)
 	data[0] = uint8ToBCD(uint8(dt.Second()))
 	data[1] = uint8ToBCD(uint8(dt.Minute()))
 	data[2] = uint8ToBCD(uint8(dt.Hour()))
@@ -118,21 +115,16 @@ func (d *Device) SetTime(dt time.Time) error {
 	data[5] = uint8ToBCD(uint8(dt.Month()) | centuryFlag)
 	data[6] = uint8ToBCD(year)
 
-	err = legacy.WriteRegister(d.bus, uint8(d.Address), REG_TIMEDATE, data)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return d.bus.Tx(d.Address, append([]byte{REG_TIMEDATE}, data...), nil)
 }
 
 // ReadTime returns the date and time
 func (d *Device) ReadTime() (dt time.Time, err error) {
 	data := make([]uint8, 7)
-	err = legacy.ReadRegister(d.bus, uint8(d.Address), REG_TIMEDATE, data)
-	if err != nil {
+	if err = d.d.ReadData(REG_TIMEDATE, data); err != nil {
 		return
 	}
+
 	second := bcdToInt(data[0] & 0x7F)
 	minute := bcdToInt(data[1])
 	hour := hoursBCDToInt(data[2])
@@ -150,12 +142,264 @@ func (d *Device) ReadTime() (dt time.Time, err error) {
 
 // ReadTemperature returns the temperature in millicelsius (mC)
 func (d *Device) ReadTemperature() (int32, error) {
-	data := make([]uint8, 2)
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_TEMP, data)
+	temp, err := d.d.Read16(REG_TEMP)
 	if err != nil {
 		return 0, err
 	}
-	return milliCelsius(data[0], data[1]), nil
+	return milliCelsius(temp), nil
+}
+
+// GetSqwPinMode returns the current square wave output frequency
+func (d *Device) GetSqwPinMode() SqwPinMode {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return SQW_OFF
+	}
+
+	control &= 0x1C // turn off INTCON
+	if control&0x04 != 0 {
+		return SQW_OFF
+	}
+
+	return SqwPinMode(control)
+}
+
+// SetSqwPinMode sets the square wave output mode to the given frequency
+func (d *Device) SetSqwPinMode(mode SqwPinMode) error {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return err
+	}
+
+	control &^= 0x04 // turn off INTCON
+	control &^= 0x18 // set freq bits to 0
+
+	control |= uint8(mode)
+
+	return d.d.Write8(REG_CONTROL, control)
+}
+
+// SetAlarm1 sets alarm1 to the given time and mode
+func (d *Device) SetAlarm1(dt time.Time, mode Alarm1Mode) error {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return err
+	}
+	if control&(1<<INTCN) == 0x00 {
+		return errors.New("INTCN has to be disabled")
+	}
+
+	A1M1 := uint8((mode & 0x01) << 7)
+	A1M2 := uint8((mode & 0x02) << 6)
+	A1M3 := uint8((mode & 0x04) << 5)
+	A1M4 := uint8((mode & 0x08) << 4)
+	DY_DT := uint8((mode & 0x10) << 2)
+
+	day := dt.Day()
+	if DY_DT > 0 {
+		day = dowToDS3231(int(dt.Weekday()))
+	}
+
+	alarm1 := uint32(uint8ToBCD(uint8(dt.Second()))|A1M1) << 24
+	alarm1 |= uint32(uint8ToBCD(uint8(dt.Minute()))|A1M2) << 16
+	alarm1 |= uint32(uint8ToBCD(uint8(dt.Hour()))|A1M3) << 8
+	alarm1 |= uint32(uint8ToBCD(uint8(day)) | A1M4 | DY_DT)
+
+	if err := d.d.Write32(REG_ALARMONE, alarm1); err != nil {
+		return err
+	}
+
+	control |= AlarmFlag_Alarm1
+	return d.d.Write8(REG_CONTROL, control)
+}
+
+// ReadAlarm1 returns the alarm1 time
+func (d *Device) ReadAlarm1() (dt time.Time, err error) {
+	data := make([]uint8, 4)
+	if err = d.d.ReadData(REG_ALARMONE, data); err != nil {
+		return
+	}
+	second := bcdToInt(data[0] & 0x7F)
+	minute := bcdToInt(data[1] & 0x7F)
+	hour := hoursBCDToInt(data[2] & 0x3F)
+
+	isDayOfWeek := (data[3] & 0x40) >> 6
+	var day int
+	if isDayOfWeek > 0 {
+		day = bcdToInt(data[3] & 0x0F)
+	} else {
+		day = bcdToInt(data[3] & 0x3F)
+	}
+
+	dt = time.Date(2000, 5, day, hour, minute, second, 0, time.UTC)
+	return
+}
+
+// SetAlarm2 sets alarm2 to the given time and mode
+func (d *Device) SetAlarm2(dt time.Time, mode Alarm2Mode) error {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return err
+	}
+	if control&(1<<INTCN) == 0x00 {
+		return errors.New("INTCN has to be disabled")
+	}
+
+	A2M2 := uint8((mode & 0x01) << 7)
+	A2M3 := uint8((mode & 0x02) << 6)
+	A2M4 := uint8((mode & 0x04) << 5)
+	DY_DT := uint8((mode & 0x08) << 3)
+
+	day := dt.Day()
+	if DY_DT > 0 {
+		day = dowToDS3231(int(dt.Weekday()))
+	}
+
+	data := make([]uint8, 4)
+	data[0] = uint8ToBCD(uint8(dt.Minute())) | A2M2
+	data[1] = uint8ToBCD(uint8(dt.Hour())) | A2M3
+	data[2] = uint8ToBCD(uint8(day)) | A2M4 | DY_DT
+	if err = d.bus.Tx(d.Address, append([]byte{REG_ALARMTWO}, data...), nil); err != nil {
+		return err
+	}
+
+	control |= AlarmFlag_Alarm2
+	return d.d.Write8(REG_CONTROL, control)
+}
+
+// ReadAlarm2 returns the alarm2 time
+func (d *Device) ReadAlarm2() (dt time.Time, err error) {
+	data := make([]uint8, 3)
+	if err = d.d.ReadData(REG_ALARMTWO, data); err != nil {
+		return
+	}
+	minute := bcdToInt(data[0] & 0x7F)
+	hour := hoursBCDToInt(data[1] & 0x3F)
+
+	isDayOfWeek := (data[2] & 0x40) >> 6
+	var day int
+	if isDayOfWeek > 0 {
+		day = bcdToInt(data[2] & 0x0F)
+	} else {
+		day = bcdToInt(data[2] & 0x3F)
+	}
+
+	dt = time.Date(2000, 5, day, hour, minute, 0, 0, time.UTC)
+	return
+}
+
+// IsEnabledAlarm1 returns true when alarm1 is enabled
+func (d *Device) IsEnabledAlarm1() bool {
+	return d.isEnabledAlarm(1)
+}
+
+// SetEnabledAlarm1 sets the enabled status of alarm1
+func (d *Device) SetEnabledAlarm1(enable bool) error {
+	if enable {
+		return d.enableAlarm(1)
+	}
+	return d.disableAlarm(1)
+}
+
+// IsEnabledAlarm2 returns true when alarm2 is enabled
+func (d *Device) IsEnabledAlarm2() bool {
+	return d.isEnabledAlarm(2)
+}
+
+// SetEnabledAlarm2 sets the enabled status of alarm2
+func (d *Device) SetEnabledAlarm2(enable bool) error {
+	if enable {
+		return d.enableAlarm(2)
+	}
+	return d.disableAlarm(2)
+}
+
+// ClearAlarm1 clears status of alarm1
+func (d *Device) ClearAlarm1() error {
+	return d.clearAlarm(1)
+}
+
+// ClearAlarm2 clears status of alarm2
+func (d *Device) ClearAlarm2() error {
+	return d.clearAlarm(2)
+}
+
+// IsAlarm1Fired returns true when alarm1 is firing
+func (d *Device) IsAlarm1Fired() bool {
+	return d.isAlarmFired(1)
+}
+
+// IsAlarm2Fired returns true when alarm2 is firing
+func (d *Device) IsAlarm2Fired() bool {
+	return d.isAlarmFired(2)
+}
+
+// SetEnabled32K sets the enabled status of the 32KHz output
+func (d *Device) SetEnabled32K(enable bool) error {
+	status, err := d.d.Read8(REG_STATUS)
+	if err != nil {
+		return err
+	}
+
+	if enable {
+		status |= 1 << EN32KHZ
+	} else {
+		status &^= 1 << EN32KHZ
+	}
+
+	return d.d.Write8(REG_STATUS, status)
+}
+
+// IsEnabled32K returns true when the 32KHz output is enabled
+func (d *Device) IsEnabled32K() bool {
+	status, err := d.d.Read8(REG_STATUS)
+	if err != nil {
+		return false
+	}
+	return (status & (1 << EN32KHZ)) != 0x00
+}
+
+func (d *Device) disableAlarm(alarm_num uint8) error {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return err
+	}
+	control &^= (1 << (alarm_num - 1))
+	return d.d.Write8(REG_CONTROL, control)
+}
+
+func (d *Device) enableAlarm(alarm_num uint8) error {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return err
+	}
+	control |= (1 << (alarm_num - 1))
+	return d.d.Write8(REG_CONTROL, control)
+}
+
+func (d *Device) isEnabledAlarm(alarm_num uint8) bool {
+	control, err := d.d.Read8(REG_CONTROL)
+	if err != nil {
+		return false
+	}
+	return (control & (1 << (alarm_num - 1))) != 0x00
+}
+
+func (d *Device) clearAlarm(alarm_num uint8) error {
+	status, err := d.d.Read8(REG_STATUS)
+	if err != nil {
+		return err
+	}
+	status &^= (1 << (alarm_num - 1))
+	return d.d.Write8(REG_STATUS, status)
+}
+
+func (d *Device) isAlarmFired(alarm_num uint8) bool {
+	status, err := d.d.Read8(REG_STATUS)
+	if err != nil {
+		return false
+	}
+	return (status & (1 << (alarm_num - 1))) != 0x00
 }
 
 // milliCelsius converts the raw temperature bytes (msb and lsb) from the DS3231
@@ -172,8 +416,8 @@ func (d *Device) ReadTemperature() (int32, error) {
 // 16-bit signed integer in units of centi Celsius (1/100 deg C) with no loss of
 // precision or dynamic range. But for backwards compatibility, let's instead
 // convert this into a 32-bit signed integer in units of milli Celsius.
-func milliCelsius(msb uint8, lsb uint8) int32 {
-	t256 := int16(uint16(msb)<<8 | uint16(lsb))
+func milliCelsius(tempBytes uint16) int32 {
+	t256 := int16(uint16(tempBytes>>8)<<8 | uint16(tempBytes&0xFF))
 	t1000 := int32(t256) / 64 * 250
 	return t1000
 }
@@ -200,3 +444,11 @@ func hoursBCDToInt(value uint8) (hour int) {
 	}
 	return
 }
+
+// dowToDS3231 converts the day of the week to internal DS3231 format
+func dowToDS3231(d int) int {
+	if d == 0 {
+		return 7
+	}
+	return d
+}

ds3231/ds3231_test.go

@@ -5,71 +5,71 @@ import (
 )
 
 func TestPositiveMilliCelsius(t *testing.T) {
-	t1000 := milliCelsius(0, 0)
+	t1000 := milliCelsius(0)
 	if t1000 != 0 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0, 0b01000000)
+	t1000 = milliCelsius(0b0000000001000000)
 	if t1000 != 250 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0, 0b10000000)
+	t1000 = milliCelsius(0b0000000010000000)
 	if t1000 != 500 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0, 0b11000000)
+	t1000 = milliCelsius(0b0000000011000000)
 	if t1000 != 750 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(1, 0b00000000)
+	t1000 = milliCelsius(0b0000000100000000)
 	if t1000 != 1000 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(2, 0b00000000)
+	t1000 = milliCelsius(0b0000001000000000)
 	if t1000 != 2000 {
 		t.Fatal(t1000)
 	}
 
 	// highest temperature is 127.750C
-	t1000 = milliCelsius(0x7f, 0b11000000)
+	t1000 = milliCelsius(0b0111111111000000)
 	if t1000 != 127750 {
 		t.Fatal(t1000)
 	}
 }
 
 func TestNegativeMilliCelsius(t *testing.T) {
-	t1000 := milliCelsius(0xff, 0b11000000)
+	t1000 := milliCelsius(0b1111111111000000)
 	if t1000 != -250 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0xff, 0b10000000)
+	t1000 = milliCelsius(0b1111111110000000)
 	if t1000 != -500 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0xff, 0b01000000)
+	t1000 = milliCelsius(0b1111111101000000)
 	if t1000 != -750 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0xff, 0b00000000)
+	t1000 = milliCelsius(0b1111111100000000)
 	if t1000 != -1000 {
 		t.Fatal(t1000)
 	}
 
-	t1000 = milliCelsius(0xfe, 0b00000000)
+	t1000 = milliCelsius(0b1111111000000000)
 	if t1000 != -2000 {
 		t.Fatal(t1000)
 	}
 
 	// lowest temperature is -128.000C
-	t1000 = milliCelsius(0x80, 0b00000000)
+	t1000 = milliCelsius(0b1000000000000000)
 	if t1000 != -128000 {
 		t.Fatal(t1000)
 	}

ds3231/registers.go

@@ -46,3 +46,52 @@ const (
 	AlarmTwo      Mode = 4
 	ModeAlarmBoth Mode = 5
 )
+
+// SQW Pin Modes
+type SqwPinMode uint8
+
+const (
+	SQW_OFF  SqwPinMode = 0x1C
+	SQW_1HZ  SqwPinMode = 0x00
+	SQW_1KHZ SqwPinMode = 0x08
+	SQW_4KHZ SqwPinMode = 0x10
+	SQW_8KHZ SqwPinMode = 0x18
+)
+
+// Alarm1 Modes define which parts of the set alarm time has to match the current timestamp of the clock device for
+// alarm1 to fire
+type Alarm1Mode uint8
+
+const (
+	// Alarm1 fires every second
+	A1_PER_SECOND Alarm1Mode = 0x0F
+	// Alarm1 fires when the seconds match
+	A1_SECOND Alarm1Mode = 0x0E
+	// Alarm1 fires when both seconds and minutes match
+	A1_MINUTE Alarm1Mode = 0x0C
+	// Alarm1 fires when seconds, minutes and hours match
+	A1_HOUR Alarm1Mode = 0x08
+	// Alarm1 fires when seconds, minutes, hours and the day of the month match
+	A1_DATE Alarm1Mode = 0x00
+	// Alarm1 fires when seconds, minutes, hours and the day of the week match
+	A1_DAY Alarm1Mode = 0x10
+)
+
+// Alarm2 Modes define which parts of the set alarm time has to match the current timestamp of the clock device for
+// alarm2 to fire.
+//
+// Alarm2 only supports matching down to the minute unlike alarm1 which supports matching down to the second.
+type Alarm2Mode uint8
+
+const (
+	// Alarm2 fires every minute
+	A2_PER_MINUTE Alarm2Mode = 0x07
+	// Alarm2 fires when the minutes match
+	A2_MINUTE Alarm2Mode = 0x06
+	// Alarm2 fires when both minutes and hours match
+	A2_HOUR Alarm2Mode = 0x04
+	// Alarm2 fires when minutes, hours and the day of the month match
+	A2_DATE Alarm2Mode = 0x00
+	// Alarm2 fires when minutes, hours and the day of the week match
+	A2_DAY Alarm2Mode = 0x08
+)

examples/bno08x/i2c/main.go

@@ -0,0 +1,66 @@
+// Package main provides a basic example of using the BNO08x driver
+// to read rotation vector (quaternion) data from the sensor.
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/bno08x"
+)
+
+func main() {
+	time.Sleep(2 * time.Second) // Wait for sensor to power up
+	// Initialize I2C bus
+	i2c := machine.I2C0
+	err := i2c.Configure(machine.I2CConfig{
+		Frequency: 400 * machine.KHz,
+	})
+	if err != nil {
+		println("Failed to configure I2C:", err.Error())
+		return
+	}
+
+	println("Initializing BNO08x sensor...")
+
+	// Create and configure sensor using I2C
+	sensor := bno08x.NewI2C(i2c)
+	err = sensor.Configure(bno08x.Config{})
+	if err != nil {
+		println("Failed to configure sensor:", err.Error())
+		return
+	}
+
+	println("Sensor initialized successfully")
+
+	// Enable Game Rotation Vector reports at 100Hz (10000 microseconds = 10ms interval)
+	// Using Game Rotation Vector (0x08) to match the working channel_debug test
+	err = sensor.EnableReport(bno08x.SensorGameRotationVector, 10000)
+	if err != nil {
+		println("Failed to enable game rotation vector:", err.Error())
+		return
+	}
+
+	println("Reading rotation vectors...")
+	println("Format: Real I J K Accuracy")
+
+	// Add a delay after enabling reports (Arduino does this)
+	time.Sleep(100 * time.Millisecond)
+
+	// Main loop - read and display quaternion data
+	for {
+		event, ok := sensor.GetSensorEvent()
+		if ok && (event.ID() == bno08x.SensorRotationVector || event.ID() == bno08x.SensorGameRotationVector) {
+			q := event.Quaternion()
+			if event.ID() == bno08x.SensorRotationVector {
+				println(q.Real, q.I, q.J, q.K, event.QuaternionAccuracy())
+			} else {
+				// GameRotationVector doesn't have accuracy
+				println(q.Real, q.I, q.J, q.K)
+			}
+		}
+
+		// Arduino uses 10ms delay in loop
+		time.Sleep(10 * time.Millisecond)
+	}
+}

examples/ds3231/alarms/main.go

@@ -0,0 +1,74 @@
+// Connects to an DS3231 I2C Real Time Clock (RTC) and sets both alarms. It then repeatedly checks
+// if the alarms are firing and prints out a message if that is the case.
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/ds3231"
+)
+
+func main() {
+	machine.I2C0.Configure(machine.I2CConfig{})
+
+	rtc := ds3231.New(machine.I2C0)
+	rtc.Configure()
+
+	valid := rtc.IsTimeValid()
+	if !valid {
+		date := time.Date(2019, 12, 05, 20, 34, 12, 0, time.UTC)
+		rtc.SetTime(date)
+	}
+
+	// Set alarm1 so it triggers when the seconds match 59 => repeats every minute at dd:hh:mm:59
+	if err := rtc.SetAlarm1(time.Date(0, 0, 0, 0, 0, 59, 0, time.UTC), ds3231.A1_SECOND); err != nil {
+		println("Error while setting Alarm1")
+	}
+	if err := rtc.SetEnabledAlarm1(true); err != nil {
+		println("Error while enabling Alarm1")
+	}
+
+	// Set alarm2 so it triggers when the minutes match 35 => repeats every hour at dd:hh:35:ss
+	if err := rtc.SetAlarm2(time.Date(0, 0, 0, 0, 35, 0, 0, time.UTC), ds3231.A2_MINUTE); err != nil {
+		println("Error while setting Alarm2")
+	}
+	if err := rtc.SetEnabledAlarm2(true); err != nil {
+		println("Error while enabling Alarm2")
+	}
+
+	running := rtc.IsRunning()
+	if !running {
+		err := rtc.SetRunning(true)
+		if err != nil {
+			println("Error configuring RTC")
+		}
+	}
+
+	for {
+		dt, err := rtc.ReadTime()
+		if err != nil {
+			println("Error reading date:", err)
+			continue
+		}
+
+		a1 := rtc.IsAlarm1Fired()
+		a2 := rtc.IsAlarm2Fired()
+
+		println(dt.Format(time.DateTime), "A1:", a1, "A2:", a2)
+
+		if a1 {
+			if err := rtc.ClearAlarm1(); err != nil {
+				println("Error while clearing alarm1")
+			}
+		}
+		if a2 {
+			if err := rtc.ClearAlarm2(); err != nil {
+				println("Error while clearing alarm2")
+			}
+
+		}
+
+		time.Sleep(time.Second * 1)
+	}
+}

examples/ds3231/basic/main.go

@@ -3,10 +3,9 @@ package main
 
 import (
 	"machine"
+	"strconv"
 	"time"
 
-	"fmt"
-
 	"tinygo.org/x/drivers/ds3231"
 )
 
@@ -26,19 +25,19 @@ func main() {
 	if !running {
 		err := rtc.SetRunning(true)
 		if err != nil {
-			fmt.Println("Error configuring RTC")
+			println("Error configuring RTC")
 		}
 	}
 
 	for {
 		dt, err := rtc.ReadTime()
 		if err != nil {
-			fmt.Println("Error reading date:", err)
+			println("Error reading date:", err)
 		} else {
-			fmt.Printf("Date: %d/%s/%02d %02d:%02d:%02d \r\n", dt.Year(), dt.Month(), dt.Day(), dt.Hour(), dt.Minute(), dt.Second())
+			println(dt.Format(time.DateTime))
 		}
 		temp, _ := rtc.ReadTemperature()
-		fmt.Printf("Temperature: %.2f °C \r\n", float32(temp)/1000)
+		println("Temperature:", strconv.FormatFloat(float64(temp)/1000, 'f', -1, 32), "°C")
 
 		time.Sleep(time.Second * 1)
 	}

examples/si5351/main.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/si5351"
+)
+
+// Simple demo of the SI5351 clock generator.
+// This is like the Arduino library example:
+//   https://github.com/adafruit/Adafruit_Si5351_Library/blob/master/examples/si5351/si5351.ino
+// Which will configure the chip with:
+//  - PLL A at 900mhz
+//  - PLL B at 616.66667mhz
+//  - Clock 0 at 112.5mhz, using PLL A as a source divided by 8
+//  - Clock 1 at 13.5531mhz, using PLL B as a source divided by 45.5
+//  - Clock 2 at 10.76khz, using PLL B as a source divided by 900 and further divided with an R divider of 64.
+
+func main() {
+	time.Sleep(5 * time.Second)
+
+	println("Si5351 Clockgen Test")
+	println()
+
+	// Configure I2C bus
+	machine.I2C0.Configure(machine.I2CConfig{})
+
+	// Create driver instance
+	clockgen := si5351.New(machine.I2C0)
+
+	// Verify device wired properly
+	connected, err := clockgen.Connected()
+	if err != nil {
+		println("Unable to read device status")
+		time.Sleep(time.Second)
+	}
+	if !connected {
+		for {
+			println("Unable to detect si5351 device")
+			time.Sleep(time.Second)
+		}
+	}
+
+	// Initialise device
+	clockgen.Configure()
+
+	// Now configue the PLLs and clock outputs.
+	// The PLLs can be configured with a multiplier and division of the on-board
+	// 25mhz reference crystal.  For example configure PLL A to 900mhz by multiplying
+	// by 36.  This uses an integer multiplier which is more accurate over time
+	// but allows less of a range of frequencies compared to a fractional
+	// multiplier shown next.
+	clockgen.ConfigurePLL(si5351.PLL_A, 36, 0, 1) // Multiply 25mhz by 36
+	println("PLL A frequency: 900mhz")
+
+	// And next configure PLL B to 616.6667mhz by multiplying 25mhz by 24.667 using
+	// the fractional multiplier configuration.  Notice you specify the integer
+	// multiplier and then a numerator and denominator as separate values, i.e.
+	// numerator 2 and denominator 3 means 2/3 or 0.667.  This fractional
+	// configuration is susceptible to some jitter over time but can set a larger
+	// range of frequencies.
+	clockgen.ConfigurePLL(si5351.PLL_B, 24, 2, 3) // Multiply 25mhz by 24.667 (24 2/3)
+	println("PLL B frequency: 616.6667mhz")
+
+	// Now configure the clock outputs.  Each is driven by a PLL frequency as input
+	// and then further divides that down to a specific frequency.
+	// Configure clock 0 output to be driven by PLL A divided by 8, so an output
+	// of 112.5mhz (900mhz / 8).  Again this uses the most precise integer division
+	// but can't set as wide a range of values.
+	clockgen.ConfigureMultisynth(0, si5351.PLL_A, 8, 0, 1) // Divide by 8 (8 0/1)
+	println("Clock 0: 112.5mhz")
+
+	// Next configure clock 1 to be driven by PLL B divided by 45.5 to get
+	// 13.5531mhz (616.6667mhz / 45.5).  This uses fractional division and again
+	// notice the numerator and denominator are explicitly specified.  This is less
+	// precise but allows a large range of frequencies.
+	clockgen.ConfigureMultisynth(1, si5351.PLL_B, 45, 1, 2) // Divide by 45.5 (45 1/2)
+	println("Clock 1: 13.5531mhz")
+
+	// Finally configure clock 2 to be driven by PLL B divided once by 900 to get
+	// down to 685.15 khz and then further divided by a special R divider that
+	// divides 685.15 khz by 64 to get a final output of 10.706khz.
+	clockgen.ConfigureMultisynth(2, si5351.PLL_B, 900, 0, 1) // Divide by 900 (900 0/1)
+	// Set the R divider, this can be a value of:
+	//  - R_DIV_1: divider of 1
+	//  - R_DIV_2: divider of 2
+	//  - R_DIV_4: divider of 4
+	//  - R_DIV_8: divider of 8
+	//  - R_DIV_16: divider of 16
+	//  - R_DIV_32: divider of 32
+	//  - R_DIV_64: divider of 64
+	//  - R_DIV_128: divider of 128
+	clockgen.ConfigureRdiv(2, si5351.R_DIV_64)
+	println("Clock 2: 10.706khz")
+
+	// After configuring PLLs and clocks, enable the outputs.
+	clockgen.EnableOutputs()
+
+	time.Sleep(time.Second)
+
+	clockgen.DisableOutputs()
+	println("All outputs disabled for 5 seconds")
+	time.Sleep(5 * time.Second)
+
+	// Now use SetFrequency to re-set the frequencies of the outputs
+	on := false
+	for {
+		if on {
+			println("Setting Clock 0 output off")
+			clockgen.OutputEnable(0, false)
+			on = false
+		} else {
+			println("Setting Clock 0 output to 100mhz")
+			clockgen.SetFrequency(100*machine.MHz, 0, si5351.PLL_A)
+			on = true
+		}
+		time.Sleep(5 * time.Second)
+	}
+}

examples/ssd1289/main.go

@@ -5,6 +5,7 @@ import (
 	"machine"
 	"math/rand"
 
+	"tinygo.org/x/drivers/internal/pin"
 	"tinygo.org/x/drivers/ssd1289"
 )
 
@@ -16,7 +17,7 @@ func main() {
 	//consider creating a more efficient bus implementation that uses
 	//your microcontrollers built in "ports"
 	//see rp2040bus.go for an example for the rapsberry pi pico
-	bus := ssd1289.NewPinBus([16]machine.Pin{
+	bus := ssd1289.NewPinBus([16]pin.Output{
 		machine.GP4,  //DB0
 		machine.GP5,  //DB1
 		machine.GP6,  //DB2

examples/w5500/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"machine"
+	"net"
+	"net/netip"
+	"time"
+
+	"tinygo.org/x/drivers/netdev"
+	"tinygo.org/x/drivers/w5500"
+)
+
+func main() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		Frequency: 33 * machine.MHz,
+	})
+	machine.GPIO17.Configure(machine.PinConfig{Mode: machine.PinOutput})
+
+	eth := w5500.New(machine.SPI0, machine.GPIO17)
+	eth.Configure(w5500.Config{
+		MAC:        net.HardwareAddr{0xee, 0xbe, 0xe9, 0xa9, 0xb6, 0x4f},
+		IP:         netip.AddrFrom4([4]byte{192, 168, 1, 2}),
+		SubnetMask: netip.AddrFrom4([4]byte{255, 255, 255, 0}),
+		Gateway:    netip.AddrFrom4([4]byte{192, 168, 1, 1}),
+	})
+	netdev.UseNetdev(eth)
+
+	for {
+		if eth.LinkStatus() != w5500.LinkStatusUp {
+			println("Waiting for link to be up")
+
+			time.Sleep(1 * time.Second)
+			continue
+		}
+		break
+	}
+}

ft6336/ft6336.go

@@ -1,3 +1,6 @@
+// Guarded because still unsure of how to deal with interrupt drivers.
+//go:build tinygo
+
 // Package ft6336 provides a driver for the FT6336 I2C Self-Capacitive touch
 // panel controller.
 //

hd44780/hd44780.go

@@ -210,7 +210,7 @@ func (d *Device) SendCommand(command byte) {
 	d.bus.SetCommandMode(true)
 	d.bus.Write([]byte{command})
 
-	for d.busy(command == DISPLAY_CLEAR || command == CURSOR_HOME) {
+	for d.isBusy(command == DISPLAY_CLEAR || command == CURSOR_HOME) {
 	}
 }
 
@@ -219,7 +219,7 @@ func (d *Device) sendData(data byte) {
 	d.bus.SetCommandMode(false)
 	d.bus.Write([]byte{data})
 
-	for d.busy(false) {
+	for d.isBusy(false) {
 	}
 }
 
@@ -231,9 +231,9 @@ func (d *Device) CreateCharacter(cgramAddr uint8, data []byte) {
 	}
 }
 
-// busy returns true when hd447890 is busy
+// isBusy returns true when hd447890 is isBusy
 // or after the timeout specified
-func (d *Device) busy(longDelay bool) bool {
+func (d *Device) isBusy(longDelay bool) bool {
 	if d.bus.WriteOnly() {
 		// Can't read busy flag if write only, so sleep a bit then return
 		if longDelay {
@@ -261,7 +261,7 @@ func (d *Device) busy(longDelay bool) bool {
 
 // Busy returns true when hd447890 is busy
 func (d *Device) Busy() bool {
-	return d.busy(false)
+	return d.isBusy(false)
 }
 
 // Size returns the current size of the display.

internal/regmap/device8tx.go

@@ -1,196 +0,0 @@
-// Package regmap provides transaction-based interfaces for reading and writing
-// to device registers over I2C and SPI buses with pre-allocated buffers.
-package regmap
-
-import (
-	"errors"
-
-	"tinygo.org/x/drivers"
-)
-
-var (
-	// errNotInTx indicates an operation was attempted outside of an active transaction.
-	errNotInTx = errors.New("device not in Tx")
-
-	// errInTx indicates a transaction was started while another is still active.
-	errInTx = errors.New("device already in Tx")
-
-	// errShortWriteBuffer indicates the write buffer is too small for the requested operation.
-	errShortWriteBuffer = errors.New("device write buffer too short")
-
-	// errShortReadBuffer indicates the read buffer is too small for the requested operation.
-	errShortReadBuffer = errors.New("device read buffer too short")
-)
-
-// Device8Txer wraps a Device8 to provide buffered transaction support for
-// I2C and SPI operations. It maintains pre-allocated buffers to avoid heap
-// allocations during register access operations.
-//
-// Users must call SetBuffers to configure the write and read buffers before
-// initiating transactions.
-type Device8Txer struct {
-	Device8
-	writeBuf []byte // Pre-allocated buffer for write operations
-	readBuf  []byte // Pre-allocated buffer for read operations
-	inTx     bool   // Tracks whether a transaction is currently active
-}
-
-// SetTxBuffers configures the write and read buffers for this device.
-// These buffers are reused across transactions to avoid heap allocations.
-//
-// The writebuf should be large enough to hold the register address plus
-// all data bytes to be written in a single transaction.
-func (d *Device8Txer) SetTxBuffers(writebuf, readbuf []byte) {
-	d.readBuf = readbuf
-	d.writeBuf = writebuf
-}
-
-// Tx8 represents an active transaction for an 8-bit register device.
-// It tracks the write buffer and current offset as data is added to the transaction.
-//
-// Use AddWriteByte or AddWriteData to add data to the transaction, then call
-// DoTxI2C or DoTxSPI to execute the transaction over the bus.
-type Tx8 struct {
-	dw  *Device8Txer // Reference to the parent device
-	off int          // Current offset in the write buffer
-}
-
-// Tx initiates a new transaction for writing to the specified register address.
-//
-// Parameters:
-//   - writeAddr: The 8-bit register address to write to
-//
-// Returns a Tx8 handle that can be used to add data and execute the transaction.
-//
-// Returns an error if:
-//   - A transaction is already active (errInTx)
-//   - The write buffer is too short (errShortWriteBuffer)
-func (dw *Device8Txer) Tx(writeAddr uint8) (Tx8, error) {
-	if dw.inTx {
-		return Tx8{}, errInTx
-	} else if len(dw.writeBuf) < 1 {
-		return Tx8{}, errShortWriteBuffer
-	}
-	dw.writeBuf[0] = writeAddr
-	return Tx8{dw: dw, off: 1}, nil
-}
-
-// AddWriteData appends multiple bytes to the current transaction's write buffer.
-//
-// Parameters:
-//   - buf: Variable number of bytes to add to the transaction
-//
-// Returns an error if:
-//   - No transaction is active (errNotInTx)
-//   - The write buffer doesn't have enough space (errShortWriteBuffer)
-func (tx *Tx8) AddWriteData(buf ...byte) error {
-	if !tx.dw.inTx {
-		return errNotInTx
-	}
-	avail := tx.dw.writeBuf[tx.off:]
-	if len(avail) < len(buf) {
-		return errShortWriteBuffer
-	}
-	n := copy(avail, buf)
-	tx.off += n
-	return nil
-}
-
-// AddWriteByte appends a single byte to the current transaction's write buffer.
-//
-// Parameters:
-//   - b: The byte to add to the transaction
-//
-// Returns an error if:
-//   - No transaction is active (errNotInTx)
-//   - The write buffer doesn't have enough space (errShortWriteBuffer)
-func (tx *Tx8) AddWriteByte(b byte) error {
-	if !tx.dw.inTx {
-		return errNotInTx
-	}
-	avail := tx.dw.writeBuf[tx.off:]
-	if len(avail) < 1 {
-		return errShortWriteBuffer
-	}
-	avail[0] = b
-	tx.off++
-	return nil
-}
-
-// DoTxI2C executes the transaction over an I2C bus.
-//
-// This performs a combined write-read I2C transaction, first sending the
-// register address and any data added to the transaction, then reading
-// the specified number of bytes from the device.
-//
-// Parameters:
-//   - bus: The I2C bus to communicate over
-//   - deviceAddr: The I2C address of the target device
-//   - readLength: Number of bytes to read from the device
-//
-// Returns the read data as a slice of the internal read buffer, valid until
-// the next transaction. The transaction is automatically freed after execution.
-//
-// Returns an error if:
-//   - No transaction is active (errNotInTx)
-//   - The read buffer is too short (errShortReadBuffer)
-//   - The I2C transaction fails
-func (tx *Tx8) DoTxI2C(bus drivers.I2C, deviceAddr uint16, readLength int) ([]byte, error) {
-	if tx.off == 0 || !tx.dw.inTx {
-		return nil, errNotInTx
-	}
-	defer tx.freeTx()
-	if len(tx.dw.readBuf) < readLength {
-		return nil, errShortReadBuffer
-	}
-	rbuf := tx.dw.readBuf[:readLength]
-	err := bus.Tx(deviceAddr, tx.dw.writeBuf[:tx.off], rbuf)
-	if err != nil {
-		return nil, err
-	}
-	return rbuf, err
-}
-
-// DoTxSPI executes the transaction over an SPI bus.
-//
-// This performs a full-duplex SPI transaction, simultaneously writing the
-// register address and data while reading the same number of bytes from the device.
-//
-// If no read buffer was configured (readBuf is nil), this performs a write-only
-// transaction and returns nil without error.
-//
-// Parameters:
-//   - bus: The SPI bus to communicate over
-//
-// Returns the read data as a slice of the internal read buffer (same length as
-// the write data), valid until the next transaction. The transaction is
-// automatically freed after execution.
-//
-// Returns an error if:
-//   - No transaction is active (errNotInTx)
-//   - The read buffer is too short (errShortReadBuffer)
-//   - The SPI transaction fails
-func (tx *Tx8) DoTxSPI(bus drivers.SPI) (readBuf []byte, err error) {
-	if tx.off == 0 || !tx.dw.inTx {
-		return nil, errNotInTx
-	}
-	defer tx.freeTx()
-	if tx.dw.readBuf == nil {
-		err = bus.Tx(tx.dw.writeBuf[:tx.off], nil) // Special case, only use write buffer functionality.
-		return nil, err
-	} else if len(readBuf) < tx.off {
-		return nil, errShortReadBuffer
-	}
-	rbuf := tx.dw.readBuf[:tx.off]
-	err = bus.Tx(tx.dw.writeBuf[:tx.off], rbuf)
-	if err != nil {
-		return nil, err
-	}
-	return rbuf, err
-}
-
-// freeTx marks the transaction as complete, allowing a new transaction to be started.
-// This is called internally by DoTxI2C and DoTxSPI after the transaction completes.
-func (tx *Tx8) freeTx() {
-	tx.dw.inTx = false
-}

internal/regmap/regmap_test.go

@@ -1,34 +0,0 @@
-package regmap
-
-import (
-	"fmt"
-
-	"tinygo.org/x/drivers"
-)
-
-func ExampleDevice8Txer() {
-	// Initialization.
-	var dtx Device8Txer
-	dtx.SetTxBuffers(make([]byte, 256), make([]byte, 256))
-
-	// Usage.
-	const (
-		defaultAddr = 65
-		REG_WRITE   = 0x1f
-		IOCTL_CALL  = 0xc0
-	)
-	tx, err := dtx.Tx(REG_WRITE)
-	if err != nil {
-		panic(err)
-	}
-	err = tx.AddWriteData(IOCTL_CALL, 0x80, 0x80)
-	if err != nil {
-		panic(err)
-	}
-	var bus drivers.I2C
-	readData, err := tx.DoTxI2C(bus, defaultAddr, 20)
-	if err != nil {
-		panic(err)
-	}
-	fmt.Println(readData)
-}

max6675/max6675.go

@@ -3,9 +3,9 @@ package max6675
 
 import (
 	"errors"
-	"machine"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 // ErrThermocoupleOpen is returned when the thermocouple input is open.
@@ -14,16 +14,16 @@ var ErrThermocoupleOpen = errors.New("thermocouple input open")
 
 type Device struct {
 	bus drivers.SPI
-	cs  machine.Pin
+	cs  pin.OutputFunc
 }
 
 // Create a new Device to read from a MAX6675 thermocouple.
 // Pins must be configured before use.  Frequency for SPI
 // should be 4.3MHz maximum.
-func NewDevice(bus drivers.SPI, cs machine.Pin) *Device {
+func NewDevice(bus drivers.SPI, cs pin.Output) *Device {
 	return &Device{
 		bus: bus,
-		cs:  cs,
+		cs:  cs.Set,
 	}
 }
 

max72xx/max72xx.go

@@ -3,31 +3,36 @@
 package max72xx
 
 import (
-	"machine"
-
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 type Device struct {
-	bus drivers.SPI
-	cs  machine.Pin
+	bus           drivers.SPI
+	cs            pin.OutputFunc
+	configurePins func()
 }
 
 // NewDriver creates a new max7219 connection. The SPI wire must already be configured
 // The SPI frequency must not be higher than 10MHz.
 // parameter cs: the datasheet also refers to this pin as "load" pin.
-func NewDevice(bus drivers.SPI, cs machine.Pin) *Device {
+func NewDevice(bus drivers.SPI, cs pin.Output) *Device {
 	return &Device{
 		bus: bus,
-		cs:  cs,
+		cs:  cs.Set,
+		configurePins: func() {
+			legacy.ConfigurePinOut(cs)
+		},
 	}
 }
 
 // Configure setups the pins.
 func (driver *Device) Configure() {
-	outPutConfig := machine.PinConfig{Mode: machine.PinOutput}
-
-	driver.cs.Configure(outPutConfig)
+	if driver.configurePins == nil {
+		panic(legacy.ErrConfigBeforeInstantiated)
+	}
+	driver.configurePins()
 }
 
 // SetScanLimit sets the scan limit. Maximum is 8.

mcp2515/mcp2515.go

@@ -8,18 +8,20 @@ package mcp2515 // import "tinygo.org/x/drivers/mcp2515"
 import (
 	"errors"
 	"fmt"
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 // Device wraps MCP2515 SPI CAN Module.
 type Device struct {
-	spi     SPI
-	cs      machine.Pin
-	msg     *CANMsg
-	mcpMode byte
+	spi           SPI
+	cs            pin.OutputFunc
+	msg           *CANMsg
+	mcpMode       byte
+	configurePins func()
 }
 
 // CANMsg stores CAN message fields.
@@ -36,15 +38,18 @@ const (
 )
 
 // New returns a new MCP2515 driver. Pass in a fully configured SPI bus.
-func New(b drivers.SPI, csPin machine.Pin) *Device {
+func New(b drivers.SPI, csPin pin.Output) *Device {
 	d := &Device{
 		spi: SPI{
 			bus: b,
 			tx:  make([]byte, 0, bufferSize),
 			rx:  make([]byte, 0, bufferSize),
 		},
-		cs:  csPin,
+		cs:  csPin.Set,
 		msg: &CANMsg{},
+		configurePins: func() {
+			legacy.ConfigurePinOut(csPin)
+		},
 	}
 
 	return d
@@ -52,7 +57,10 @@ func New(b drivers.SPI, csPin machine.Pin) *Device {
 
 // Configure sets up the device for communication.
 func (d *Device) Configure() {
-	d.cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	if d.configurePins == nil {
+		panic(legacy.ErrConfigBeforeInstantiated)
+	}
+	d.configurePins()
 }
 
 const beginTimeoutValue int = 10

pcd8544/pcd8544.go

@@ -6,18 +6,18 @@ package pcd8544 // import "tinygo.org/x/drivers/pcd8544"
 import (
 	"errors"
 	"image/color"
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 // Device wraps an SPI connection.
 type Device struct {
 	bus        drivers.SPI
-	dcPin      machine.Pin
-	rstPin     machine.Pin
-	scePin     machine.Pin
+	dcPin      pin.OutputFunc
+	rstPin     pin.OutputFunc
+	scePin     pin.OutputFunc
 	buffer     []byte
 	width      int16
 	height     int16
@@ -30,12 +30,12 @@ type Config struct {
 }
 
 // New creates a new PCD8544 connection. The SPI bus must already be configured.
-func New(bus drivers.SPI, dcPin, rstPin, scePin machine.Pin) *Device {
+func New(bus drivers.SPI, dcPin, rstPin, scePin pin.Output) *Device {
 	return &Device{
 		bus:    bus,
-		dcPin:  dcPin,
-		rstPin: rstPin,
-		scePin: scePin,
+		dcPin:  dcPin.Set,
+		rstPin: rstPin.Set,
+		scePin: scePin.Set,
 	}
 }
 

pixel/image.go

@@ -149,6 +149,20 @@ func (img Image[T]) setPixel(index int, c T) {
 		}
 
 		return
+	case zeroColor.BitsPerPixel() == 2:
+		// Grayscale2bit.
+		offset := index / 4      // 4 pixels per byte
+		shift := 6 - (index%4)*2 // bits: 6, 4, 2, 0
+
+		ptr := (*byte)(unsafe.Add(img.data, offset))
+
+		raw := *(*uint8)(unsafe.Pointer(&c))
+		gray := raw & 0b11
+
+		mask := byte(0b11 << shift)
+		*ptr = (*ptr &^ mask) | (gray << shift)
+		return
+
 	case zeroColor.BitsPerPixel()%8 == 0:
 		// Each color starts at a whole byte offset.
 		// This is the easy case.
@@ -206,6 +220,13 @@ func (img Image[T]) Get(x, y int) T {
 		ptr := (*byte)(unsafe.Add(img.data, offset))
 		c = ((*ptr >> (7 - uint8(bits))) & 0x1) > 0
 		return any(c).(T)
+	case zeroColor.BitsPerPixel() == 2:
+		// Grayscale2bit.
+		offset := index / 4      // 4 pixels per byte
+		shift := 6 - (index%4)*2 // bits: 6, 4, 2, 0
+		ptr := (*byte)(unsafe.Add(img.data, offset))
+		value := ((*ptr) >> shift) & 0b11
+		return any(Grayscale2bit(value)).(T)
 	case zeroColor.BitsPerPixel()%8 == 0:
 		// Colors like RGB565, RGB888, etc.
 		offset := index * int(unsafe.Sizeof(zeroColor))

pixel/image_test.go

@@ -9,9 +9,30 @@ import (
 	"tinygo.org/x/drivers/pixel"
 )
 
+func TestImageRGB888(t *testing.T) {
+	image := pixel.NewImage[pixel.RGB888](5, 3)
+	if width, height := image.Size(); width != 5 || height != 3 {
+		t.Errorf("image.Size(): expected 5, 3 but got %d, %d", width, height)
+	}
+	for _, c := range []color.RGBA{
+		{R: 0xff, A: 0xff},
+		{G: 0xff, A: 0xff},
+		{B: 0xff, A: 0xff},
+		{R: 0x10, A: 0xff},
+		{G: 0x10, A: 0xff},
+		{B: 0x10, A: 0xff},
+	} {
+		image.Set(4, 2, pixel.NewColor[pixel.RGB888](c.R, c.G, c.B))
+		c2 := image.Get(4, 2).RGBA()
+		if c2 != c {
+			t.Errorf("failed to roundtrip color: expected %v but got %v", c, c2)
+		}
+	}
+}
+
 func TestImageRGB565BE(t *testing.T) {
 	image := pixel.NewImage[pixel.RGB565BE](5, 3)
-	if width, height := image.Size(); width != 5 && height != 3 {
+	if width, height := image.Size(); width != 5 || height != 3 {
 		t.Errorf("image.Size(): expected 5, 3 but got %d, %d", width, height)
 	}
 	for _, c := range []color.RGBA{
@@ -30,9 +51,30 @@ func TestImageRGB565BE(t *testing.T) {
 	}
 }
 
+func TestImageRGB555(t *testing.T) {
+	image := pixel.NewImage[pixel.RGB555](5, 3)
+	if width, height := image.Size(); width != 5 || height != 3 {
+		t.Errorf("image.Size(): expected 5, 3 but got %d, %d", width, height)
+	}
+	for _, c := range []color.RGBA{
+		{R: 0xff, A: 0xff},
+		{G: 0xff, A: 0xff},
+		{B: 0xff, A: 0xff},
+		{R: 0x10, A: 0xff},
+		{G: 0x10, A: 0xff},
+		{B: 0x10, A: 0xff},
+	} {
+		image.Set(4, 2, pixel.NewColor[pixel.RGB555](c.R, c.G, c.B))
+		c2 := image.Get(4, 2).RGBA()
+		if c2 != c {
+			t.Errorf("failed to roundtrip color: expected %v but got %v", c, c2)
+		}
+	}
+}
+
 func TestImageRGB444BE(t *testing.T) {
 	image := pixel.NewImage[pixel.RGB444BE](5, 3)
-	if width, height := image.Size(); width != 5 && height != 3 {
+	if width, height := image.Size(); width != 5 || height != 3 {
 		t.Errorf("image.Size(): expected 5, 3 but got %d, %d", width, height)
 	}
 	for _, c := range []color.RGBA{
@@ -65,9 +107,69 @@ func TestImageRGB444BE(t *testing.T) {
 	}
 }
 
+func TestImageGrayscale2bit(t *testing.T) {
+	image := pixel.NewImage[pixel.Grayscale2bit](128, 64)
+
+	if width, height := image.Size(); width != 128 || height != 64 {
+		t.Errorf("image.Size(): expected 128, 64 but got %d, %d", width, height)
+	}
+
+	// Define test colors representing 4 Grayscale levels.
+	testColors := []color.RGBA{
+		{R: 0x00, G: 0x00, B: 0x00, A: 0xff}, // black
+		{R: 0x55, G: 0x55, B: 0x55, A: 0xff}, // dark gray
+		{R: 0xaa, G: 0xaa, B: 0xaa, A: 0xff}, // light gray
+		{R: 0xff, G: 0xff, B: 0xff, A: 0xff}, // white
+	}
+
+	// Single pixel roundtrip test at a fixed coordinate.
+	for _, c := range testColors {
+		encoded := pixel.NewColor[pixel.Grayscale2bit](c.R, c.G, c.B)
+		image.Set(5, 3, encoded)
+		actual := image.Get(5, 3).RGBA()
+		if actual != c {
+			t.Errorf("failed to roundtrip color: expected %v but got %v", c, actual)
+		}
+	}
+
+	// Multi-coordinate test across the image.
+	for x := 0; x < 8; x++ {
+		for y, c := range testColors {
+			encoded := pixel.NewColor[pixel.Grayscale2bit](c.R, c.G, c.B)
+			image.Set(x, y, encoded)
+			actual := image.Get(x, y).RGBA()
+			if actual != c {
+				t.Errorf("Set/Get mismatch at (%d,%d): expected %v but got %v", x, y, c, actual)
+			}
+		}
+	}
+}
+
+func TestNewGrayscale2bitMapping(t *testing.T) {
+	testCases := []struct {
+		input  color.RGBA
+		expect pixel.Grayscale2bit
+	}{
+		{color.RGBA{R: 0x00, G: 0x00, B: 0x00}, 0}, // 0
+		{color.RGBA{R: 0x3F, G: 0x3F, B: 0x3F}, 0}, // 63
+		{color.RGBA{R: 0x40, G: 0x40, B: 0x40}, 1}, // 64
+		{color.RGBA{R: 0x7F, G: 0x7F, B: 0x7F}, 1}, // 127
+		{color.RGBA{R: 0x80, G: 0x80, B: 0x80}, 2}, // 128
+		{color.RGBA{R: 0xBF, G: 0xBF, B: 0xBF}, 2}, // 191
+		{color.RGBA{R: 0xC0, G: 0xC0, B: 0xC0}, 3}, // 192
+		{color.RGBA{R: 0xFF, G: 0xFF, B: 0xFF}, 3}, // 255
+	}
+	for _, tc := range testCases {
+		actual := pixel.NewColor[pixel.Grayscale2bit](tc.input.R, tc.input.G, tc.input.B)
+		if actual != tc.expect {
+			t.Errorf("NewGrayscale2bit(%#v) = %d, want %d", tc.input, actual, tc.expect)
+		}
+	}
+}
+
 func TestImageMonochrome(t *testing.T) {
 	image := pixel.NewImage[pixel.Monochrome](128, 64)
-	if width, height := image.Size(); width != 128 && height != 64 {
+	if width, height := image.Size(); width != 128 || height != 64 {
 		t.Errorf("image.Size(): expected 128, 64 but got %d, %d", width, height)
 	}
 	for _, expected := range []color.RGBA{
@@ -194,6 +296,9 @@ func TestImageNoise(t *testing.T) {
 	t.Run("RGB444BE", func(t *testing.T) {
 		testImageNoiseN[pixel.RGB444BE](t)
 	})
+	t.Run("Grayscale2bit", func(t *testing.T) {
+		testImageNoiseN[pixel.Grayscale2bit](t)
+	})
 	t.Run("Monochrome", func(t *testing.T) {
 		testImageNoiseN[pixel.Monochrome](t)
 	})

pixel/pixel.go

@@ -16,7 +16,7 @@ import (
 // particular display. Each pixel is at least 1 byte in size.
 // The color format is sRGB (or close to it) in all cases except for 1-bit.
 type Color interface {
-	RGB888 | RGB565BE | RGB555 | RGB444BE | Monochrome
+	RGB888 | RGB565BE | RGB555 | RGB444BE | Grayscale2bit | Monochrome
 
 	BaseColor
 }
@@ -50,6 +50,8 @@ func NewColor[T Color](r, g, b uint8) T {
 		return any(NewRGB555(r, g, b)).(T)
 	case RGB444BE:
 		return any(NewRGB444BE(r, g, b)).(T)
+	case Grayscale2bit:
+		return any(NewGrayscale2bit(r, g, b)).(T)
 	case Monochrome:
 		return any(NewMonochrome(r, g, b)).(T)
 	default:
@@ -161,9 +163,9 @@ func (c RGB555) BitsPerPixel() int {
 
 func (c RGB555) RGBA() color.RGBA {
 	color := color.RGBA{
-		R: uint8(c>>10) << 3,
-		G: uint8(c>>5) << 3,
-		B: uint8(c) << 3,
+		R: (uint8(c) & 0x1F) << 3,
+		G: (uint8(c>>5) & 0x1F) << 3,
+		B: (uint8(c>>10) & 0x1F) << 3,
 		A: 255,
 	}
 	// Correct color rounding, so that 0xff roundtrips back to 0xff.
@@ -204,6 +206,34 @@ func (c RGB444BE) RGBA() color.RGBA {
 	return color
 }
 
+// Grayscale2bit represents a 2-bit Grayscale value (4 levels: black, dark gray, light gray, white).
+type Grayscale2bit uint8
+
+func NewGrayscale2bit(r, g, b uint8) Grayscale2bit {
+	// Convert RGB to luminance using standard weights (approximation of human perception)
+	// Use shift-based operations to reduce processing time.
+	// luminance := (299*uint32(r) + 587*uint32(g) + 114*uint32(b)) / 1000
+	luminance := (77*uint32(r) + 150*uint32(g) + 29*uint32(b)) >> 8
+	// Map to 2-bit value: 0–63 => 0, 64–127 => 1, 128–191 => 2, 192–255 => 3
+	return Grayscale2bit((luminance >> 6) & 0b11)
+}
+
+func (c Grayscale2bit) BitsPerPixel() int {
+	return 2
+}
+
+func (c Grayscale2bit) RGBA() color.RGBA {
+	// Expand 2-bit Grayscale back to 8-bit (0–255) using multiplication
+	// 0 → 0x00, 1 → 0x55, 2 → 0xAA, 3 → 0xFF (i.e., multiply by 85)
+	gray := uint8(c&0b11) * 85
+	return color.RGBA{
+		R: gray,
+		G: gray,
+		B: gray,
+		A: 255,
+	}
+}
+
 type Monochrome bool
 
 func NewMonochrome(r, g, b uint8) Monochrome {

scd4x/registers.go

@@ -22,4 +22,5 @@ const (
 	CmdStartLowPowerPeriodicMeasurement = 0x21AC
 	CmdStartPeriodicMeasurement         = 0x21B1
 	CmdStopPeriodicMeasurement          = 0x3F86
+	CmdMeasureSingleShot                = 0x219D
 )

scd4x/scd4x.go

@@ -82,6 +82,13 @@ func (d *Device) StartLowPowerPeriodicMeasurement() error {
 	return d.sendCommand(CmdStartLowPowerPeriodicMeasurement)
 }
 
+// MeasureSingleShot starts a single measurement cycle (SCD41 only). After this
+// command is complete, the caller should wait for 5000ms before trying to read
+// the result.
+func (d *Device) MeasureSingleShot() error {
+	return d.sendCommand(CmdMeasureSingleShot)
+}
+
 // ReadData reads the data from the sensor and caches it.
 func (d *Device) ReadData() error {
 	if err := d.sendCommandWithResult(CmdReadMeasurement, d.rx[0:9]); err != nil {
@@ -93,7 +100,18 @@ func (d *Device) ReadData() error {
 	return nil
 }
 
+// Update reads new data from the sensor (if new data is available) and caches
+// it for reading in the CO2, Temperature, and Humidity methods.
+func (d *Device) Update(measurements drivers.Measurement) error {
+	if measurements&(drivers.Temperature|drivers.Humidity|drivers.Concentration) != 0 {
+		return d.ReadData()
+	}
+	return nil
+}
+
 // ReadCO2 returns the CO2 concentration in PPM (parts per million).
+//
+// Deprecated: use Update() and CO2() instead.
 func (d *Device) ReadCO2() (co2 int32, err error) {
 	ok, err := d.DataReady()
 	if err != nil {
@@ -105,7 +123,14 @@ func (d *Device) ReadCO2() (co2 int32, err error) {
 	return int32(d.co2), err
 }
 
+// CO2 returns last read the CO2 concentration in PPM (parts per million).
+func (d *Device) CO2() int32 {
+	return int32(d.co2)
+}
+
 // ReadTemperature returns the temperature in celsius milli degrees (°C/1000)
+//
+// Deprecated: use Update() and Temperature() instead.
 func (d *Device) ReadTemperature() (temperature int32, err error) {
 	ok, err := d.DataReady()
 	if err != nil {
@@ -114,8 +139,14 @@ func (d *Device) ReadTemperature() (temperature int32, err error) {
 	if ok {
 		err = d.ReadData()
 	}
+	return d.Temperature(), err
+}
+
+// Temperature returns the last read temperature in celsius milli degrees
+// (°C/1000).
+func (d *Device) Temperature() int32 {
 	// temp = -45 + 175 * value / 2¹⁶
-	return (-1 * 45000) + (21875 * (int32(d.temperature)) / 8192), err
+	return (-1 * 45000) + (21875 * (int32(d.temperature)) / 8192)
 }
 
 // ReadTempC returns the value in the temperature value in Celsius.
@@ -130,6 +161,11 @@ func (d *Device) ReadTempF() float32 {
 }
 
 // ReadHumidity returns the current relative humidity in %rH.
+//
+// Warning: the value returned here is less precise than the humidity returned
+// from Humidity()!
+//
+// Deprecated: use Update() and Temperature() instead.
 func (d *Device) ReadHumidity() (humidity int32, err error) {
 	ok, err := d.DataReady()
 	if err != nil {
@@ -142,18 +178,20 @@ func (d *Device) ReadHumidity() (humidity int32, err error) {
 	return (25 * int32(d.humidity)) / 16384, err
 }
 
+// Humidity returns the relative humidity in hundredths of a percent (in other
+// words, with a range 0..10_000).
+//
+// Warning: the value returned here is of a different scale (more precise) than
+// ReadHumidity()!
+func (d *Device) Humidity() int32 {
+	return (2500 * int32(d.humidity)) / 16384
+}
+
 func (d *Device) sendCommand(command uint16) error {
 	binary.BigEndian.PutUint16(d.tx[0:], command)
 	return d.bus.Tx(uint16(d.Address), d.tx[0:2], nil)
 }
 
-func (d *Device) sendCommandWithValue(command, value uint16) error {
-	binary.BigEndian.PutUint16(d.tx[0:], command)
-	binary.BigEndian.PutUint16(d.tx[2:], value)
-	d.tx[4] = crc8(d.tx[2:4])
-	return d.bus.Tx(uint16(d.Address), d.tx[0:5], nil)
-}
-
 func (d *Device) sendCommandWithResult(command uint16, result []byte) error {
 	binary.BigEndian.PutUint16(d.tx[0:], command)
 	if err := d.bus.Tx(uint16(d.Address), d.tx[0:2], nil); err != nil {

si5351/registers.go

@@ -0,0 +1,122 @@
+package si5351
+
+// The I2C address which this device listens to.
+const AddressDefault = 0x60     // Assumes ADDR pin is low
+const AddressAlternative = 0x61 // Assumes ADDR pin is high
+
+const (
+	OUTPUT_ENABLE_CONTROL = 3
+
+	CLK0_CONTROL = 16
+	CLK1_CONTROL = 17
+	CLK2_CONTROL = 18
+	CLK3_CONTROL = 19
+	CLK4_CONTROL = 20
+	CLK5_CONTROL = 21
+	CLK6_CONTROL = 22
+	CLK7_CONTROL = 23
+
+	MULTISYNTH0_PARAMETERS_1 = 42
+	MULTISYNTH0_PARAMETERS_3 = 44
+	MULTISYNTH1_PARAMETERS_1 = 50
+	MULTISYNTH1_PARAMETERS_3 = 52
+	MULTISYNTH2_PARAMETERS_1 = 58
+	MULTISYNTH2_PARAMETERS_3 = 60
+
+	SPREAD_SPECTRUM_PARAMETERS = 149
+
+	PLL_RESET = 177
+
+	CRYSTAL_INTERNAL_LOAD_CAPACITANCE = 183
+
+	FANOUT_ENABLE = 187
+)
+
+const (
+	CRYSTAL_LOAD_6PF  = (1 << 6)
+	CRYSTAL_LOAD_8PF  = (2 << 6)
+	CRYSTAL_LOAD_10PF = (3 << 6)
+)
+
+const (
+	CRYSTAL_FREQ_25MHZ = 25000000
+	CRYSTAL_FREQ_27MHZ = 27000000
+)
+
+const (
+	PLL_A = iota
+	PLL_B
+)
+
+const (
+	R_DIV_1 = iota
+	R_DIV_2
+	R_DIV_4
+	R_DIV_8
+	R_DIV_16
+	R_DIV_32
+	R_DIV_64
+	R_DIV_128
+)
+
+const (
+	MULTISYNTH_DIV_4 = 4
+	MULTISYNTH_DIV_6 = 6
+	MULTISYNTH_DIV_8 = 8
+)
+
+// Frequency constants (in Hz)
+const (
+	CLKOUT_MIN_FREQ        = 8000      // 8 kHz
+	CLKOUT_MAX_FREQ        = 150000000 // 150 MHz
+	MULTISYNTH_MAX_FREQ    = 150000000 // 150 MHz
+	MULTISYNTH_SHARE_MAX   = 100000000 // 100 MHz
+	MULTISYNTH_DIVBY4_FREQ = 150000000 // 150 MHz
+	PLL_VCO_MIN            = 600000000 // 600 MHz
+	PLL_VCO_MAX            = 900000000 // 900 MHz
+)
+
+const (
+	SI5351_PLL_C_MAX = 1048575
+)
+
+// Bit masks for FANOUT_ENABLE register
+const (
+	CLKIN_ENABLE      = (1 << 7)
+	XTAL_ENABLE       = (1 << 6)
+	MULTISYNTH_ENABLE = (1 << 4)
+)
+
+const (
+	FANOUT_CLKIN = iota
+	FANOUT_XO
+	FANOUT_MS
+)
+
+// Clock source selection masks for CLKx_CONTROL registers
+const (
+	CLK_INPUT_MASK           = 0x3 // Bits 0 and 1
+	CLK_INPUT_XTAL           = 0x0
+	CLK_INPUT_CLKIN          = 0x1
+	CLK_INPUT_MULTISYNTH_0_4 = 0x2
+	CLK_INPUT_MULTISYNTH_N   = 0x3
+)
+
+// Clock source selection
+const (
+	CLK_SRC_XTAL = iota
+	CLK_SRC_CLKIN
+	CLK_SRC_MS0
+	CLK_SRC_MS
+)
+
+const (
+	CLK_INVERT = 1 << 4
+)
+
+const (
+	CLK_DRIVE_STRENGTH_2MA = 0
+	CLK_DRIVE_STRENGTH_4MA = 1
+	CLK_DRIVE_STRENGTH_6MA = 2
+	CLK_DRIVE_STRENGTH_8MA = 3
+)

si5351/si5351.go

@@ -0,0 +1,789 @@
+package si5351
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/regmap"
+)
+
+// Device wraps an I2C connection to a SI5351 device.
+type Device struct {
+	bus     drivers.I2C
+	Address uint8
+
+	rw             regmap.Device8I2C
+	initialised    bool
+	crystalFreq    uint32
+	crystalLoad    uint8
+	pllaConfigured bool
+	pllaFreq       uint32
+	pllbConfigured bool
+	pllbFreq       uint32
+	lastRdivValue  [3]uint8
+}
+
+var ErrNotInitialised = errors.New("Si5351 not initialised")
+var ErrInvalidParameter = errors.New("Si5351 invalid parameter")
+
+// New creates a new SI5351 connection. The I2C bus must already be configured.
+//
+// This function only creates the Device object, it does not touch the device.
+func New(bus drivers.I2C) Device {
+	rw := regmap.Device8I2C{}
+	rw.SetBus(bus, AddressDefault, binary.BigEndian)
+
+	return Device{
+		bus:         bus,
+		rw:          rw,
+		Address:     AddressDefault,
+		crystalFreq: CRYSTAL_FREQ_25MHZ,
+		crystalLoad: CRYSTAL_LOAD_10PF,
+	}
+}
+
+// Configure sets up the device for communication
+// TODO error handling
+func (d *Device) Configure() error {
+	// // Disable all outputs setting CLKx_DIS high
+	d.rw.Write8(OUTPUT_ENABLE_CONTROL, 0xFF)
+
+	// Set the load capacitance for the XTAL
+	d.rw.Write8(CRYSTAL_INTERNAL_LOAD_CAPACITANCE, d.crystalLoad)
+
+	// Power down all output drivers
+	buf := []byte{CLK0_CONTROL, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80}
+	d.bus.Tx(uint16(d.Address), buf, nil)
+
+	// Disable spread spectrum output.
+	if err := d.DisableSpreadSpectrum(); err != nil {
+		return err
+	}
+
+	d.initialised = true
+
+	return nil
+}
+
+// Connected returns whether a device at SI5351 address has been found.
+func (d *Device) Connected() (bool, error) {
+	if err := d.bus.Tx(uint16(d.Address), []byte{}, []byte{0}); err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// EnableSpreadSpectrum enables spread spectrum modulation to reduce EMI.
+func (d *Device) EnableSpreadSpectrum() error {
+	data, err := d.rw.Read8(SPREAD_SPECTRUM_PARAMETERS)
+	if err != nil {
+		return err
+	}
+
+	data |= 0x80
+	return d.rw.Write8(SPREAD_SPECTRUM_PARAMETERS, data)
+}
+
+func (d *Device) DisableSpreadSpectrum() error {
+	data, err := d.rw.Read8(SPREAD_SPECTRUM_PARAMETERS)
+	if err != nil {
+		return err
+	}
+
+	data &^= 0x80
+	return d.rw.Write8(SPREAD_SPECTRUM_PARAMETERS, data)
+}
+
+func (d *Device) OutputEnable(output uint8, enable bool) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	// Read the current value of the OUTPUT_ENABLE_CONTROL register
+	regVal, err := d.rw.Read8(OUTPUT_ENABLE_CONTROL)
+	if err != nil {
+		return err
+	}
+
+	// Modify regVal based on clk and enable
+	if enable {
+		regVal &= ^(1 << output)
+	} else {
+		regVal |= (1 << output)
+	}
+
+	// Write the modified value back to the OUTPUT_ENABLE_CONTROL register
+	return d.rw.Write8(OUTPUT_ENABLE_CONTROL, regVal)
+}
+
+func (d *Device) EnableOutputs() error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	return d.rw.Write8(OUTPUT_ENABLE_CONTROL, 0x00)
+}
+
+func (d *Device) DisableOutputs() error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+	return d.rw.Write8(OUTPUT_ENABLE_CONTROL, 0xFF)
+}
+
+// packRegSet packs P1, P2, P3 values into the 8-byte register format
+// used by both PLL and Multisynth configuration.
+// For multisynth, rDivBits should contain the R divider value shifted left by 4.
+// For PLL, rDivBits should be 0.
+func packRegSet(p1, p2, p3 uint32, rDivBits uint8) [8]byte {
+	var data [8]byte
+	data[0] = uint8((p3 & 0xFF00) >> 8)
+	data[1] = uint8(p3 & 0xFF)
+	data[2] = uint8((p1&0x30000)>>16) | rDivBits
+	data[3] = uint8((p1 & 0xFF00) >> 8)
+	data[4] = uint8(p1 & 0xFF)
+	data[5] = uint8(((p3 & 0xF0000) >> 12) | ((p2 & 0xF0000) >> 16))
+	data[6] = uint8((p2 & 0xFF00) >> 8)
+	data[7] = uint8(p2 & 0xFF)
+	return data
+}
+
+// ConfigurePLL sets the multiplier for the specified PLL
+// pll   The PLL to configure, which must be one of the following:
+// - PLL_A
+// - PLL_B
+//
+// mult  The PLL integer multiplier (must be between 15 and 90)
+//
+// num   The 20-bit numerator for fractional output (0..1,048,575).
+// Set this to '0' for integer output.
+//
+// denom The 20-bit denominator for fractional output (1..1,048,575).
+// Set this to '1' or higher to avoid divider by zero errors.
+//
+// PLL Configuration
+// fVCO is the PLL output, and must be between 600..900MHz, where:
+//
+// fVCO = fXTAL * (a+(b/c))
+//
+// fXTAL = the crystal input frequency
+// a     = an integer between 15 and 90
+// b     = the fractional numerator (0..1,048,575)
+// c     = the fractional denominator (1..1,048,575)
+//
+// NOTE: Try to use integers whenever possible to avoid clock jitter
+// (only use the a part, setting b to '0' and c to '1').
+//
+// See: http://www.silabs.com/Support%20Documents/TechnicalDocs/AN619.pdf
+func (d *Device) ConfigurePLL(pll uint8, mult uint8, num uint32, denom uint32) error {
+	// Basic validation
+	switch {
+	case !d.initialised:
+		return ErrNotInitialised
+	// mult = 15..90
+	case !((mult > 14) && (mult < 91)):
+		return ErrInvalidParameter
+	// Avoid divide by zero
+	case !(denom > 0):
+		return ErrInvalidParameter
+	// 20-bit limit
+	case !(num <= 0xFFFFF):
+		return ErrInvalidParameter
+	// 20-bit limit
+	case !(denom <= 0xFFFFF):
+		return ErrInvalidParameter
+	}
+
+	// Calculate PLL register values
+	var p1, p2, p3 uint32
+	if num == 0 {
+		// Integer mode
+		p1 = 128*uint32(mult) - 512
+		p2 = num
+		p3 = denom
+	} else {
+		// Fractional mode
+		p1 = uint32(128*float64(mult) + math.Floor(128*(float64(num)/float64(denom))) - 512)
+		p2 = uint32(128*float64(num) - float64(denom)*math.Floor(128*(float64(num)/float64(denom))))
+		p3 = denom
+	}
+
+	// Get the appropriate starting point for the PLL registers
+	baseaddr := uint8(26)
+	if pll == PLL_B {
+		baseaddr = 34
+	}
+
+	// Pack and write registers
+	data := packRegSet(p1, p2, p3, 0)
+	if err := d.bus.Tx(uint16(baseaddr), data[:], nil); err != nil {
+		return err
+	}
+
+	// Reset both PLLs
+	if err := d.rw.Write8(PLL_RESET, (1<<7)|(1<<5)); err != nil {
+		return err
+	}
+
+	// Store the frequency settings for use with the Multisynth helper
+	fvco := float64(d.crystalFreq) * (float64(mult) + (float64(num) / float64(denom)))
+	if pll == PLL_A {
+		d.pllaConfigured = true
+		d.pllaFreq = uint32(math.Floor(fvco))
+	} else {
+		d.pllbConfigured = true
+		d.pllbFreq = uint32(math.Floor(fvco))
+	}
+	return nil
+}
+
+// ConfigureMultisynth divider, which determines the
+// output clock frequency based on the specified PLL input.
+//
+// output    The output channel to use (0..2)
+//
+// pll       The PLL input source to use, which must be one of:
+//   - PLL_A
+//   - PLL_B
+//
+// div       The integer divider for the Multisynth output.
+//
+//	If pure integer values are used, this value must be one of:
+//	- MULTISYNTH_DIV_4
+//	- MULTISYNTH_DIV_6
+//	- MULTISYNTH_DIV_8
+//	If fractional output is used, this value must be between 8 and 900.
+//
+// num       The 20-bit numerator for fractional output (0..1,048,575).
+//
+//	Set this to '0' for integer output.
+//
+// denom     The 20-bit denominator for fractional output (1..1,048,575).
+//
+//	Set this to '1' or higher to avoid divide by zero errors.
+//
+// # Output Clock Configuration
+//
+// The multisynth dividers are applied to the specified PLL output,
+// and are used to reduce the PLL output to a valid range (500kHz
+// to 160MHz). The relationship can be seen in this formula, where
+// fVCO is the PLL output frequency and MSx is the multisynth divider:
+//
+// fOUT = fVCO / MSx
+//
+// Valid multisynth dividers are 4, 6, or 8 when using integers,
+// or any fractional values between 8 + 1/1,048,575 and 900 + 0/1
+// The following formula is used for the fractional mode divider:
+//
+// a + b / c
+//
+// a = The integer value, which must be 4, 6 or 8 in integer mode (MSx_INT=1) or 8..900 in fractional mode (MSx_INT=0).
+// b = The fractional numerator (0..1,048,575)
+// c = The fractional denominator (1..1,048,575)
+//
+// NOTE: Try to use integers whenever possible to avoid clock jitter
+// NOTE: For output frequencies > 150MHz, you must set the divider
+//
+//	to 4 and adjust to PLL to generate the frequency (for example
+//	a PLL of 640 to generate a 160MHz output clock). This is not
+//	yet supported in the driver, which limits frequencies to 500kHz .. 150MHz.
+//
+// NOTE: For frequencies below 500kHz (down to 8kHz) Rx_DIV must be
+//
+//	used, but this isn't currently implemented in the driver.
+func (d *Device) ConfigureMultisynth(output uint8, pll uint8, div uint32, num uint32, denom uint32) error {
+	// Basic validation
+	switch {
+	case !d.initialised:
+		return ErrNotInitialised
+	// Channel range
+	case !(output < 3):
+		return fmt.Errorf("output channel must be between 0 and 2")
+	// Divider integer value
+	case !((div > 3) && (div < 2049)):
+		return ErrInvalidParameter
+	// Avoid divide by zero
+	case !(denom > 0):
+		return ErrInvalidParameter
+	// 20-bit limit
+	case !(num <= 0xFFFFF):
+		return ErrInvalidParameter
+	// 20-bit limit
+	case !(denom <= 0xFFFFF):
+		return ErrInvalidParameter
+		// Make sure the requested PLL has been initialised
+	case pll == PLL_A && !d.pllaConfigured:
+		return ErrInvalidParameter
+	case pll == PLL_B && !d.pllbConfigured:
+		return ErrInvalidParameter
+	}
+
+	// Calculate register values
+	var reg si5351RegSet
+	switch {
+	case num == 0:
+		// Integer mode
+		reg.p1 = 128*div - 512
+		reg.p2 = 0
+		reg.p3 = denom
+	case denom == 1:
+		// Fractional mode, simplified calculations
+		reg.p1 = 128*div + 128*num - 512
+		reg.p2 = 128*num - 128
+		reg.p3 = 1
+	default:
+		// Fractional mode
+		reg.p1 = uint32(128*float64(div) + math.Floor(128*(float64(num)/float64(denom))) - 512)
+		reg.p2 = uint32(128*float64(num) - float64(denom)*math.Floor(128*(float64(num)/float64(denom))))
+		reg.p3 = denom
+	}
+
+	// Determine if we should use integer mode
+	intMode := num == 0
+
+	// Use existing R divider value (0 if not previously set)
+	rDiv := d.lastRdivValue[output] >> 4
+
+	return d.setMS(output, reg, intMode, rDiv, pll)
+}
+
+func (d *Device) ConfigureRdiv(output uint8, div uint8) error {
+	// Channel range
+	if !(output < 3) {
+		return ErrInvalidParameter
+	}
+
+	var register uint8
+	switch output {
+	case 0:
+		register = MULTISYNTH0_PARAMETERS_3
+	case 1:
+		register = MULTISYNTH1_PARAMETERS_3
+	case 2:
+		register = MULTISYNTH2_PARAMETERS_3
+	}
+
+	data, err := d.rw.Read8(register)
+	if err != nil {
+		return err
+	}
+
+	d.lastRdivValue[output] = (div & 0x07) << 4
+	data = (data & 0x0F) | d.lastRdivValue[output]
+	return d.rw.Write8(register, data)
+}
+
+// si5351RegSet holds the register values for multisynth configuration
+type si5351RegSet struct {
+	p1 uint32
+	p2 uint32
+	p3 uint32
+}
+
+var ErrFrequencyOutOfRange = errors.New("Si5351 frequency out of range")
+var ErrClockConflict = errors.New("Si5351 clock conflict with existing configuration")
+
+// SetFrequency sets the clock frequency of the specified CLK output.
+// Frequency range is 8 kHz to 150 MHz.
+//
+// freq - Output frequency in Hz
+// output - Clock output (0, 1, or 2 for this driver)
+// pll - The PLL to use (PLL_A or PLL_B)
+func (d *Device) SetFrequency(freq uint64, output uint8, pll uint8) error {
+	switch {
+	case !d.initialised:
+		return ErrNotInitialised
+	case output > 2:
+		return ErrInvalidParameter
+	}
+
+	switch {
+	// Lower bounds check
+	case freq < CLKOUT_MIN_FREQ:
+		freq = CLKOUT_MIN_FREQ
+	// Upper bounds check
+	case freq > MULTISYNTH_MAX_FREQ:
+		freq = MULTISYNTH_MAX_FREQ
+	}
+
+	// Select the proper R divider value for low frequencies
+	rDiv := d.selectRDiv(&freq)
+
+	// Calculate PLL and multisynth parameters
+	var pllFreq uint64
+	switch {
+	case pll == PLL_A && d.pllaConfigured:
+		pllFreq = uint64(d.pllaFreq)
+	case pll == PLL_B && d.pllbConfigured:
+		pllFreq = uint64(d.pllbFreq)
+	default:
+		// PLL not configured, calculate optimal PLL frequency
+		pllFreq = d.calculatePLLFreq(freq)
+	}
+
+	// Calculate multisynth divider parameters
+	msReg := d.multisynthCalc(freq, pllFreq)
+
+	// Determine if we should use integer mode
+	intMode := msReg.p2 == 0
+
+	// Configure PLL if not already configured or if we need a new frequency
+	if (pll == PLL_A && !d.pllaConfigured) || (pll == PLL_B && !d.pllbConfigured) {
+		if err := d.setPLL(pllFreq, pll); err != nil {
+			return err
+		}
+	}
+
+	// Set multisynth registers
+	if err := d.setMS(output, msReg, intMode, rDiv, pll); err != nil {
+		return err
+	}
+
+	// Enable output
+	return d.OutputEnable(output, true)
+}
+
+// selectRDiv selects the appropriate R divider for low frequencies
+// and modifies the frequency accordingly
+func (d *Device) selectRDiv(freq *uint64) uint8 {
+	var rDiv uint8 = 0
+
+	if *freq >= CLKOUT_MIN_FREQ && *freq < CLKOUT_MIN_FREQ*2 {
+		rDiv = R_DIV_128
+		*freq *= 128
+	} else if *freq >= CLKOUT_MIN_FREQ*2 && *freq < CLKOUT_MIN_FREQ*4 {
+		rDiv = R_DIV_64
+		*freq *= 64
+	} else if *freq >= CLKOUT_MIN_FREQ*4 && *freq < CLKOUT_MIN_FREQ*8 {
+		rDiv = R_DIV_32
+		*freq *= 32
+	} else if *freq >= CLKOUT_MIN_FREQ*8 && *freq < CLKOUT_MIN_FREQ*16 {
+		rDiv = R_DIV_16
+		*freq *= 16
+	} else if *freq >= CLKOUT_MIN_FREQ*16 && *freq < CLKOUT_MIN_FREQ*32 {
+		rDiv = R_DIV_8
+		*freq *= 8
+	} else if *freq >= CLKOUT_MIN_FREQ*32 && *freq < CLKOUT_MIN_FREQ*64 {
+		rDiv = R_DIV_4
+		*freq *= 4
+	} else if *freq >= CLKOUT_MIN_FREQ*64 && *freq < CLKOUT_MIN_FREQ*128 {
+		rDiv = R_DIV_2
+		*freq *= 2
+	}
+
+	return rDiv
+}
+
+// calculatePLLFreq calculates an optimal PLL frequency for the given output frequency
+func (d *Device) calculatePLLFreq(freq uint64) uint64 {
+	// Try to find an integer divider that puts PLL in valid range (600-900 MHz)
+	// Start with a divider that gives us a PLL freq near 750 MHz (middle of range)
+	targetPLL := uint64(750000000)
+	divider := targetPLL / freq
+
+	// Ensure divider is in valid range (8-900 for fractional, 4/6/8 for integer)
+
+	switch {
+	case divider < 8:
+		divider = 8
+	case divider > 900:
+		divider = 900
+	}
+
+	pllFreq := freq * divider
+
+	// Ensure PLL frequency is in valid range
+	switch {
+	case pllFreq < PLL_VCO_MIN:
+		pllFreq = PLL_VCO_MIN
+	case pllFreq > PLL_VCO_MAX:
+		pllFreq = PLL_VCO_MAX
+	}
+
+	return pllFreq
+}
+
+// multisynthCalc calculates the multisynth register values
+func (d *Device) multisynthCalc(freq, pllFreq uint64) si5351RegSet {
+	var reg si5351RegSet
+
+	// Calculate the division ratio
+	// divider = pllFreq / freq
+	a := uint32(pllFreq / freq)
+	remainder := pllFreq % freq
+
+	// Calculate b and c for fractional part
+	// We use c = SI5351_PLL_C_MAX (max 20-bit value) for best resolution
+	c := uint32(SI5351_PLL_C_MAX)
+	b := uint32((uint64(remainder) * uint64(c)) / freq)
+
+	// Calculate P1, P2, P3
+	// P1 = 128 * a + floor(128 * b / c) - 512
+	// P2 = 128 * b - c * floor(128 * b / c)
+	// P3 = c
+	floor128bc := uint32((128 * uint64(b)) / uint64(c))
+
+	reg.p1 = 128*a + floor128bc - 512
+	reg.p2 = 128*b - c*floor128bc
+	reg.p3 = c
+
+	return reg
+}
+
+// setPLL configures the PLL with the specified frequency
+func (d *Device) setPLL(pllFreq uint64, pll uint8) error {
+	// Calculate PLL multiplier from crystal frequency
+	// pllFreq = crystalFreq * (a + b/c)
+	xtalFreq := uint64(d.crystalFreq)
+
+	a := uint32(pllFreq / xtalFreq)
+	remainder := pllFreq % xtalFreq
+
+	// Use max denominator for best resolution
+	c := uint32(SI5351_PLL_C_MAX)
+	b := uint32((remainder * uint64(c)) / xtalFreq)
+
+	return d.ConfigurePLL(pll, uint8(a), b, c)
+}
+
+// setMS sets the multisynth registers for the specified output
+func (d *Device) setMS(output uint8, reg si5351RegSet, intMode bool, rDiv uint8, pll uint8) error {
+	// Get the appropriate starting point for the registers
+	var baseaddr uint8
+	switch output {
+	case 0:
+		baseaddr = MULTISYNTH0_PARAMETERS_1
+	case 1:
+		baseaddr = MULTISYNTH1_PARAMETERS_1
+	case 2:
+		baseaddr = MULTISYNTH2_PARAMETERS_1
+	default:
+		return ErrInvalidParameter
+	}
+
+	// Store R divider value
+	d.lastRdivValue[output] = (rDiv & 0x07) << 4
+
+	// Pack and write registers
+	data := packRegSet(reg.p1, reg.p2, reg.p3, d.lastRdivValue[output])
+	if err := d.bus.Tx(uint16(baseaddr), data[:], nil); err != nil {
+		return err
+	}
+
+	// Configure the clk control register
+	clkControlReg := uint8(0x0F) // 8mA drive strength, powered up
+	if pll == PLL_B {
+		clkControlReg |= (1 << 5) // Use PLLB
+	}
+	if intMode {
+		clkControlReg |= (1 << 6) // Integer mode
+	}
+
+	var clkReg uint8
+	switch output {
+	case 0:
+		clkReg = CLK0_CONTROL
+	case 1:
+		clkReg = CLK1_CONTROL
+	case 2:
+		clkReg = CLK2_CONTROL
+	}
+
+	return d.rw.Write8(clkReg, clkControlReg)
+}
+
+// GetFreqStep returns the frequency step size of the radio in Hz.
+// This is the smallest frequency increment that can be achieved,
+// determined by the PLL frequency and denominator resolution.
+// If pll is PLL_A, uses PLLA settings; if PLL_B, uses PLLB settings.
+// Returns 0 if the specified PLL is not configured.
+func (d *Device) GetFreqStep(pll uint8) uint64 {
+	// The frequency step at the output is:
+	// step = pllFreq / (SI5351_PLL_C_MAX * multisynth_divider)
+	//
+	// However, since multisynth divider varies per output, we return
+	// the base step from the PLL, which is:
+	// step = pllFreq / SI5351_PLL_C_MAX
+
+	var pllFreq uint64
+
+	switch pll {
+	case PLL_A:
+		if !d.pllaConfigured {
+			return 0
+		}
+		pllFreq = uint64(d.pllaFreq)
+	case PLL_B:
+		if !d.pllbConfigured {
+			return 0
+		}
+		pllFreq = uint64(d.pllbFreq)
+	default:
+		return 0
+	}
+
+	return pllFreq / SI5351_PLL_C_MAX
+}
+
+// SetClockFanout enables or disables the specified clock fanout.
+// fanout - The fanout to configure, which must be one of:
+//   - FANOUT_CLKIN
+//   - FANOUT_XO
+//   - FANOUT_MS
+//
+// enable - true to enable the fanout, false to disable it.
+func (d *Device) SetClockFanout(fanout int, enable bool) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	// Read the current value of the FANOUT_ENABLE register
+	regVal, err := d.rw.Read8(FANOUT_ENABLE)
+	if err != nil {
+		return err
+	}
+	// Modify regVal based on fanout and enable
+	switch fanout {
+	case FANOUT_CLKIN:
+		if enable {
+			regVal |= CLKIN_ENABLE
+		} else {
+			regVal &^= CLKIN_ENABLE
+		}
+	case FANOUT_XO:
+		if enable {
+			regVal |= XTAL_ENABLE
+		} else {
+			regVal &^= XTAL_ENABLE
+		}
+	case FANOUT_MS:
+		if enable {
+			regVal |= MULTISYNTH_ENABLE
+		} else {
+			regVal &^= MULTISYNTH_ENABLE
+		}
+	default:
+		return ErrInvalidParameter
+	}
+
+	return d.rw.Write8(FANOUT_ENABLE, regVal)
+}
+
+// SetClockSource sets the clock source for a multisynth output.
+// clk - Clock output (0..7)
+// src - Clock source (see constants below)
+func (d *Device) SetClockSource(clk uint8, src uint8) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	clkReg := CLK0_CONTROL + clk
+	regVal, err := d.rw.Read8(clkReg)
+	if err != nil {
+		return err
+	}
+
+	// Clear the input source bits
+	regVal &^= CLK_INPUT_MASK
+
+	switch src {
+	case CLK_SRC_XTAL:
+		regVal |= CLK_INPUT_XTAL
+	case CLK_SRC_CLKIN:
+		regVal |= CLK_INPUT_CLKIN
+	case CLK_SRC_MS0:
+		if clk == 0 {
+			return nil // MS0 not valid for CLK0
+		}
+		regVal |= CLK_INPUT_MULTISYNTH_0_4
+	case CLK_SRC_MS:
+		regVal |= CLK_INPUT_MULTISYNTH_N
+	default:
+		return ErrInvalidParameter
+	}
+
+	return d.rw.Write8(clkReg, regVal)
+}
+
+// SetClockInvert enables or disables inversion of the clock output waveform.
+// clk - Clock output (0..7)
+// invert - true to enable inversion, false to disable
+func (d *Device) SetClockInvert(clk uint8, invert bool) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	clkReg := CLK0_CONTROL + clk
+	regVal, err := d.rw.Read8(clkReg)
+	if err != nil {
+		return err
+	}
+
+	if invert {
+		regVal |= CLK_INVERT
+	} else {
+		regVal &^= CLK_INVERT
+	}
+
+	return d.rw.Write8(clkReg, regVal)
+}
+
+// SetDriveStrength sets the drive strength of the specified clock output.
+// clk - Clock output (0..7)
+// drive - Desired drive level (use SI5351_CLK_DRIVE_STRENGTH_* constants)
+func (d *Device) SetDriveStrength(clk uint8, drive uint8) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	const mask = 0x03
+	clkReg := CLK0_CONTROL + clk
+	regVal, err := d.rw.Read8(clkReg)
+	if err != nil {
+		return err
+	}
+
+	// Clear drive strength bits
+	regVal &^= mask
+
+	switch drive {
+	case CLK_DRIVE_STRENGTH_2MA:
+		regVal |= 0x00
+	case CLK_DRIVE_STRENGTH_4MA:
+		regVal |= 0x01
+	case CLK_DRIVE_STRENGTH_6MA:
+		regVal |= 0x02
+	case CLK_DRIVE_STRENGTH_8MA:
+		regVal |= 0x03
+	default:
+		return ErrInvalidParameter
+	}
+
+	return d.rw.Write8(clkReg, regVal)
+}
+
+// SetClockPower enables or disables power to a clock output (power saving).
+// clk - Clock output (0..7)
+// enable - true to enable power, false to disable (power down)
+func (d *Device) SetClockPower(clk uint8, enable bool) error {
+	if !d.initialised {
+		return ErrNotInitialised
+	}
+
+	clkReg := CLK0_CONTROL + clk
+	regVal, err := d.rw.Read8(clkReg)
+	if err != nil {
+		return err
+	}
+
+	if enable {
+		regVal &^= 0x80 // Clear bit 7 to enable power
+	} else {
+		regVal |= 0x80 // Set bit 7 to disable power (power down)
+	}
+
+	return d.rw.Write8(clkReg, regVal)
+}

smoketest.sh

@@ -20,9 +20,11 @@ tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/bmi
 tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/bmp180/main.go
 tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/bmp280/main.go
 tinygo build -size short -o ./build/test.hex -target=trinket-m0 ./examples/bmp388/main.go
+tinygo build -size short -o ./build/test.hex -target=metro-rp2350 ./examples/bno08x/i2c/main.go
 tinygo build -size short -o ./build/test.hex -target=bluepill ./examples/ds1307/sram/main.go
 tinygo build -size short -o ./build/test.hex -target=bluepill ./examples/ds1307/time/main.go
-tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/ds3231/main.go
+tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/ds3231/alarms/main.go
+tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/ds3231/basic/main.go
 tinygo build -size short -o ./build/test.hex -target=microbit ./examples/easystepper/main.go
 tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/flash/console/spi
 tinygo build -size short -o ./build/test.hex -target=pyportal ./examples/flash/console/qspi
@@ -144,6 +146,8 @@ tinygo build -size short -o ./build/test.hex -target=pico ./examples/tmc5160/mai
 tinygo build -size short -o ./build/test.uf2 -target=nicenano ./examples/sharpmem/main.go
 tinygo build -size short -o ./build/test.hex -target=feather-nrf52840 ./examples/max6675/main.go
 tinygo build -size short -o ./build/test.hex -target=pico ./examples/ens160/main.go
+tinygo build -size short -o ./build/test.hex -target=pico ./examples/si5351/main.go
+tinygo build -size short -o ./build/test.hex -target=pico ./examples/w5500/main.go
 # network examples (espat)
 tinygo build -size short -o ./build/test.hex -target=challenger-rp2040 ./examples/net/ntpclient/
 # network examples (wifinina)

ssd1289/pinbus.go

@@ -1,15 +1,19 @@
 package ssd1289
 
-import "machine"
+import (
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
+)
 
 type pinBus struct {
-	pins [16]machine.Pin
+	pins [16]pin.Output
 }
 
-func NewPinBus(pins [16]machine.Pin) pinBus {
+func NewPinBus(pins [16]pin.Output) pinBus {
 
+	// configure GPIO pins (on baremetal targets only, for backwards compatibility)
 	for i := 0; i < 16; i++ {
-		pins[i].Configure(machine.PinConfig{Mode: machine.PinOutput})
+		legacy.ConfigurePinOut(pins[i])
 	}
 
 	return pinBus{
@@ -18,20 +22,7 @@ func NewPinBus(pins [16]machine.Pin) pinBus {
 }
 
 func (b pinBus) Set(data uint16) {
-	b.pins[15].Set((data & (1 << 15)) != 0)
-	b.pins[14].Set((data & (1 << 14)) != 0)
-	b.pins[13].Set((data & (1 << 13)) != 0)
-	b.pins[12].Set((data & (1 << 12)) != 0)
-	b.pins[11].Set((data & (1 << 11)) != 0)
-	b.pins[10].Set((data & (1 << 10)) != 0)
-	b.pins[9].Set((data & (1 << 9)) != 0)
-	b.pins[8].Set((data & (1 << 8)) != 0)
-	b.pins[7].Set((data & (1 << 7)) != 0)
-	b.pins[6].Set((data & (1 << 6)) != 0)
-	b.pins[5].Set((data & (1 << 5)) != 0)
-	b.pins[4].Set((data & (1 << 4)) != 0)
-	b.pins[3].Set((data & (1 << 3)) != 0)
-	b.pins[2].Set((data & (1 << 2)) != 0)
-	b.pins[1].Set((data & (1 << 1)) != 0)
-	b.pins[0].Set((data & (1 << 0)) != 0)
+	for i := 15; i >= 0; i-- {
+		b.pins[i].Set((data & (1 << i)) != 0)
+	}
 }

ssd1289/ssd1289.go

@@ -5,8 +5,10 @@ package ssd1289
 
 import (
 	"image/color"
-	"machine"
 	"time"
+
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 type Bus interface {
@@ -14,33 +16,34 @@ type Bus interface {
 }
 
 type Device struct {
-	rs  machine.Pin
-	wr  machine.Pin
-	cs  machine.Pin
-	rst machine.Pin
+	rs  pin.OutputFunc
+	wr  pin.OutputFunc
+	cs  pin.OutputFunc
+	rst pin.OutputFunc
 	bus Bus
 }
 
 const width = int16(240)
 const height = int16(320)
 
-func New(rs machine.Pin, wr machine.Pin, cs machine.Pin, rst machine.Pin, bus Bus) Device {
-	d := Device{
-		rs:  rs,
-		wr:  wr,
-		cs:  cs,
-		rst: rst,
+func New(rs, wr, cs, rst pin.Output, bus Bus) *Device {
+	d := &Device{
+		rs:  rs.Set,
+		wr:  wr.Set,
+		cs:  cs.Set,
+		rst: rst.Set,
 		bus: bus,
 	}
 
-	rs.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	wr.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	rst.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	// configure GPIO pins (only on baremetal targets, for backwards compatibility)
+	legacy.ConfigurePinOut(rs)
+	legacy.ConfigurePinOut(wr)
+	legacy.ConfigurePinOut(cs)
+	legacy.ConfigurePinOut(rst)
 
-	cs.High()
-	rst.High()
-	wr.High()
+	d.cs.High()
+	d.rst.High()
+	d.wr.High()
 
 	return d
 }

ssd1306/ssd1306_spi.go

@@ -1,31 +1,33 @@
 package ssd1306
 
 import (
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 type SPIBus struct {
 	wire     drivers.SPI
-	dcPin    machine.Pin
-	resetPin machine.Pin
-	csPin    machine.Pin
+	dcPin    pin.OutputFunc
+	resetPin pin.OutputFunc
+	csPin    pin.OutputFunc
 	buffer   []byte // buffer to avoid heap allocations
 }
 
 // NewSPI creates a new SSD1306 connection. The SPI wire must already be configured.
-func NewSPI(bus drivers.SPI, dcPin, resetPin, csPin machine.Pin) *Device {
-	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+func NewSPI(bus drivers.SPI, dcPin, resetPin, csPin pin.Output) *Device {
+	// configure GPIO pins (on baremetal targets only, for backwards compatibility)
+	legacy.ConfigurePinOut(dcPin)
+	legacy.ConfigurePinOut(resetPin)
+	legacy.ConfigurePinOut(csPin)
 	return &Device{
 		bus: &SPIBus{
 			wire:     bus,
-			dcPin:    dcPin,
-			resetPin: resetPin,
-			csPin:    csPin,
+			dcPin:    dcPin.Set,
+			resetPin: resetPin.Set,
+			csPin:    csPin.Set,
 		},
 	}
 }
@@ -60,7 +62,7 @@ func (b *SPIBus) flush() error {
 // tx sends data to the display
 func (b *SPIBus) tx(data []byte, isCommand bool) error {
 	b.csPin.High()
-	b.dcPin.Set(!isCommand)
+	b.dcPin(!isCommand)
 	b.csPin.Low()
 	err := b.wire.Tx(data, nil)
 	b.csPin.High()

ssd1331/ssd1331.go

@@ -5,12 +5,13 @@ package ssd1331 // import "tinygo.org/x/drivers/ssd1331"
 
 import (
 	"image/color"
-	"machine"
 
 	"errors"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 type Model uint8
@@ -19,9 +20,9 @@ type Rotation uint8
 // Device wraps an SPI connection.
 type Device struct {
 	bus         drivers.SPI
-	dcPin       machine.Pin
-	resetPin    machine.Pin
-	csPin       machine.Pin
+	dcPin       pin.OutputFunc
+	resetPin    pin.OutputFunc
+	csPin       pin.OutputFunc
 	width       int16
 	height      int16
 	batchLength int16
@@ -36,15 +37,16 @@ type Config struct {
 }
 
 // New creates a new SSD1331 connection. The SPI wire must already be configured.
-func New(bus drivers.SPI, resetPin, dcPin, csPin machine.Pin) Device {
-	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+func New(bus drivers.SPI, resetPin, dcPin, csPin pin.Output) Device {
+	// configure GPIO pins (on baremetal targets only, for backwards compatibility)
+	legacy.ConfigurePinOut(dcPin)
+	legacy.ConfigurePinOut(resetPin)
+	legacy.ConfigurePinOut(csPin)
 	return Device{
 		bus:      bus,
-		dcPin:    dcPin,
-		resetPin: resetPin,
-		csPin:    csPin,
+		dcPin:    dcPin.Set,
+		resetPin: resetPin.Set,
+		csPin:    csPin.Set,
 	}
 }
 
@@ -251,7 +253,7 @@ func (d *Device) Data(data uint8) {
 
 // Tx sends data to the display
 func (d *Device) Tx(data []byte, isCommand bool) {
-	d.dcPin.Set(!isCommand)
+	d.dcPin(!isCommand)
 	d.bus.Tx(data, nil)
 }
 

ssd1351/ssd1351.go

@@ -6,10 +6,11 @@ package ssd1351 // import "tinygo.org/x/drivers/ssd1351"
 import (
 	"errors"
 	"image/color"
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 )
 
 var (
@@ -19,17 +20,18 @@ var (
 
 // Device wraps an SPI connection.
 type Device struct {
-	bus          drivers.SPI
-	dcPin        machine.Pin
-	resetPin     machine.Pin
-	csPin        machine.Pin
-	enPin        machine.Pin
-	rwPin        machine.Pin
-	width        int16
-	height       int16
-	rowOffset    int16
-	columnOffset int16
-	bufferLength int16
+	bus           drivers.SPI
+	dcPin         pin.OutputFunc
+	resetPin      pin.OutputFunc
+	csPin         pin.OutputFunc
+	enPin         pin.OutputFunc
+	rwPin         pin.OutputFunc
+	width         int16
+	height        int16
+	rowOffset     int16
+	columnOffset  int16
+	bufferLength  int16
+	configurePins func()
 }
 
 // Config is the configuration for the display
@@ -41,14 +43,21 @@ type Config struct {
 }
 
 // New creates a new SSD1351 connection. The SPI wire must already be configured.
-func New(bus drivers.SPI, resetPin, dcPin, csPin, enPin, rwPin machine.Pin) Device {
+func New(bus drivers.SPI, resetPin, dcPin, csPin, enPin, rwPin pin.Output) Device {
 	return Device{
 		bus:      bus,
-		dcPin:    dcPin,
-		resetPin: resetPin,
-		csPin:    csPin,
-		enPin:    enPin,
-		rwPin:    rwPin,
+		dcPin:    dcPin.Set,
+		resetPin: resetPin.Set,
+		csPin:    csPin.Set,
+		enPin:    enPin.Set,
+		rwPin:    rwPin.Set,
+		configurePins: func() {
+			legacy.ConfigurePinOut(dcPin)
+			legacy.ConfigurePinOut(resetPin)
+			legacy.ConfigurePinOut(csPin)
+			legacy.ConfigurePinOut(enPin)
+			legacy.ConfigurePinOut(rwPin)
+		},
 	}
 }
 
@@ -72,12 +81,8 @@ func (d *Device) Configure(cfg Config) {
 		d.bufferLength = d.height
 	}
 
-	// configure GPIO pins
-	d.dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.enPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.rwPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	// configure GPIO pins (on baremetal targets only, for backwards compatibility)
+	d.configurePins()
 
 	// reset the device
 	d.resetPin.High()
@@ -278,7 +283,7 @@ func (d *Device) Data(data uint8) {
 
 // Tx sends data to the display
 func (d *Device) Tx(data []byte, isCommand bool) {
-	d.dcPin.Set(!isCommand)
+	d.dcPin(!isCommand)
 	d.csPin.Low()
 	d.bus.Tx(data, nil)
 	d.csPin.High()

st7735/st7735.go

@@ -5,12 +5,13 @@ package st7735 // import "tinygo.org/x/drivers/st7735"
 
 import (
 	"image/color"
-	"machine"
 	"time"
 
 	"errors"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 	"tinygo.org/x/drivers/pixel"
 )
 
@@ -39,10 +40,10 @@ type Device = DeviceOf[pixel.RGB565BE]
 // formats.
 type DeviceOf[T Color] struct {
 	bus          drivers.SPI
-	dcPin        machine.Pin
-	resetPin     machine.Pin
-	csPin        machine.Pin
-	blPin        machine.Pin
+	dcPin        pin.OutputFunc
+	resetPin     pin.OutputFunc
+	csPin        pin.OutputFunc
+	blPin        pin.OutputFunc
 	width        int16
 	height       int16
 	columnOffset int16
@@ -65,23 +66,25 @@ type Config struct {
 }
 
 // New creates a new ST7735 connection. The SPI wire must already be configured.
-func New(bus drivers.SPI, resetPin, dcPin, csPin, blPin machine.Pin) Device {
+func New(bus drivers.SPI, resetPin, dcPin, csPin, blPin pin.Output) Device {
 	return NewOf[pixel.RGB565BE](bus, resetPin, dcPin, csPin, blPin)
 }
 
 // NewOf creates a new ST7735 connection with a particular pixel format. The SPI
 // wire must already be configured.
-func NewOf[T Color](bus drivers.SPI, resetPin, dcPin, csPin, blPin machine.Pin) DeviceOf[T] {
-	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	blPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+func NewOf[T Color](bus drivers.SPI, resetPin, dcPin, csPin, blPin pin.Output) DeviceOf[T] {
+	// IMPORTANT: pin configuration should really be done outside of this driver,
+	// but for backwards compatibility with existing code, we do it here.
+	legacy.ConfigurePinOut(dcPin)
+	legacy.ConfigurePinOut(resetPin)
+	legacy.ConfigurePinOut(csPin)
+	legacy.ConfigurePinOut(blPin)
 	return DeviceOf[T]{
 		bus:      bus,
-		dcPin:    dcPin,
-		resetPin: resetPin,
-		csPin:    csPin,
-		blPin:    blPin,
+		dcPin:    dcPin.Set,
+		resetPin: resetPin.Set,
+		csPin:    csPin.Set,
+		blPin:    blPin.Set,
 	}
 }
 
@@ -423,7 +426,7 @@ func (d *DeviceOf[T]) Data(data uint8) {
 
 // Tx sends data to the display
 func (d *DeviceOf[T]) Tx(data []byte, isCommand bool) {
-	d.dcPin.Set(!isCommand)
+	d.dcPin(!isCommand)
 	d.bus.Tx(data, nil)
 }
 

version.go

@@ -2,4 +2,4 @@ package drivers
 
 // Version returns a user-readable string showing the version of the drivers package for support purposes.
 // Update this value before release of new version of software.
-const Version = "0.33.0"
+const Version = "0.34.0"

w5500/io.go

@@ -0,0 +1,104 @@
+package w5500
+
+import "time"
+
+func (d *Device) irqPoll(sockn uint8, state uint8, deadline time.Time) uint8 {
+	waitTime := 500 * time.Microsecond
+	for {
+		if !deadline.IsZero() && time.Now().After(deadline) {
+			// If a deadline is set and it has passed, return 0.
+			return sockIntUnknown
+		}
+
+		irq := d.readByte(sockInt, sockAddr(sockn)) & 0b00011111
+		if got := irq & state; got != 0 {
+			// Acknowledge the interrupt.
+			d.writeByte(sockInt, sockAddr(sockn), got)
+
+			return got
+		}
+
+		d.mu.Unlock()
+
+		time.Sleep(waitTime)
+
+		// Exponential backoff for polling.
+		waitTime *= 2
+		if waitTime > 10*time.Millisecond {
+			waitTime = 10 * time.Millisecond
+		}
+
+		d.mu.Lock()
+	}
+}
+
+func (d *Device) read(addr uint16, bsb uint8, p []byte) {
+	d.cs(false)
+	if len(p) == 0 {
+		return
+	}
+
+	d.sendReadHeader(addr, bsb)
+	_ = d.bus.Tx(nil, p)
+	d.cs(true)
+}
+
+func (d *Device) readUint16(addr uint16, bsb uint8) uint16 {
+	d.cs(false)
+	d.sendReadHeader(addr, bsb)
+	buf := d.cmdBuf
+	_ = d.bus.Tx(nil, buf[:2])
+	d.cs(true)
+	return uint16(buf[1]) | uint16(buf[0])<<8
+}
+
+func (d *Device) readByte(addr uint16, bsb uint8) byte {
+	d.cs(false)
+	d.sendReadHeader(addr, bsb)
+	r, _ := d.bus.Transfer(byte(0))
+	d.cs(true)
+	return r
+}
+
+func (d *Device) write(addr uint16, bsb uint8, p []byte) {
+	d.cs(false)
+	if len(p) == 0 {
+		return
+	}
+	d.sendWriteHeader(addr, bsb)
+	_ = d.bus.Tx(p, nil)
+	d.cs(true)
+}
+
+func (d *Device) writeUint16(addr uint16, bsb uint8, v uint16) {
+	d.cs(false)
+	d.sendWriteHeader(addr, bsb)
+	buf := d.cmdBuf
+	buf[0] = byte(v >> 8)
+	buf[1] = byte(v & 0xff)
+	_ = d.bus.Tx(buf[:2], nil)
+	d.cs(true)
+}
+
+func (d *Device) writeByte(addr uint16, bsb uint8, b byte) {
+	d.cs(false)
+	d.sendWriteHeader(addr, bsb)
+	_, _ = d.bus.Transfer(b)
+	d.cs(true)
+}
+
+func (d *Device) sendReadHeader(addr uint16, bsb uint8) {
+	buf := d.cmdBuf
+	buf[0] = byte(addr >> 8)
+	buf[1] = byte(addr & 0xff)
+	buf[2] = bsb << 3
+	_ = d.bus.Tx(buf[:], nil)
+}
+
+func (d *Device) sendWriteHeader(addr uint16, bsb uint8) {
+	buf := d.cmdBuf
+	buf[0] = byte(addr >> 8)
+	buf[1] = byte(addr & 0xff)
+	buf[2] = bsb<<3 | 0b100
+	_ = d.bus.Tx(buf[:], nil)
+}

w5500/netdev.go

@@ -0,0 +1,445 @@
+package w5500
+
+import (
+	"errors"
+	"net"
+	"net/netip"
+	"os"
+	"runtime"
+	"time"
+
+	"tinygo.org/x/drivers/netdev"
+)
+
+type socket struct {
+	sockn    uint8
+	protocol uint8
+	port     uint16
+	inUse    bool
+	closed   bool
+}
+
+func (s *socket) setProtocol(proto byte) *socket {
+	s.protocol = proto
+	return s
+}
+
+func (s *socket) setPort(port uint16) *socket {
+	s.port = port
+	return s
+}
+
+func (s *socket) setInUse(inUse bool) *socket {
+	s.inUse = inUse
+	return s
+}
+
+func (s *socket) setClosed(closed bool) *socket {
+	s.closed = closed
+	return s
+}
+
+func (s *socket) reset() {
+	s.protocol = 0
+	s.port = 0
+	s.inUse = false
+	s.closed = false
+}
+
+// GetHostByName resolves the given host name to an IP address.
+func (d *Device) GetHostByName(name string) (netip.Addr, error) {
+	d.mu.Lock()
+	dns := d.dns
+	d.mu.Unlock()
+
+	if dns == nil {
+		return netip.Addr{}, netdev.ErrNotSupported
+	}
+	return dns(name)
+}
+
+func (d *Device) Socket(domain int, stype int, protocol int) (int, error) {
+	if domain != netdev.AF_INET {
+		return -1, netdev.ErrFamilyNotSupported
+	}
+	switch {
+	case stype == netdev.SOCK_STREAM && protocol == netdev.IPPROTO_TCP:
+	case stype == netdev.SOCK_DGRAM && protocol == netdev.IPPROTO_UDP:
+	default:
+		return -1, errors.New("unsupported combination of socket type and protocol")
+	}
+
+	var proto byte
+	switch protocol {
+	case netdev.IPPROTO_TCP:
+		proto = 1 // TCP
+	case netdev.IPPROTO_UDP:
+		proto = 2 // UDP
+	default:
+		return -1, netdev.ErrNotSupported
+	}
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sockfd, sock, err := d.nextSocket()
+	if err != nil {
+		return -1, err
+	}
+
+	d.openSocket(sock.sockn, proto)
+
+	sock.setProtocol(proto).setInUse(true)
+	return sockfd, nil
+}
+
+func (d *Device) openSocket(sockn uint8, proto byte) {
+	d.writeByte(sockMode, sockAddr(sockn), proto&0x0F)
+}
+
+func (d *Device) Bind(sockfd int, ip netip.AddrPort) error {
+	// The IP address is irrelevant. The configured ip will always be used.
+	port := ip.Port()
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return err
+	}
+
+	if err = d.bindSocket(sock.sockn, port); err != nil {
+		return errors.New("could not set socket port: " + err.Error())
+	}
+
+	sock.setPort(port)
+	return nil
+}
+
+func (d *Device) bindSocket(sockn uint8, port uint16) error {
+	d.writeUint16(sockSrcPort, sockAddr(sockn), port)
+	d.socketSendCmd(sockn, sockCmdOpen)
+	if d.sockStatus(sockn) == sockStatusClosed {
+		return errors.New("socket is closed after binding")
+	}
+	return nil
+}
+
+// SetSockOpt sets the socket option for the given socket file descriptor.
+// It is not supported by the W5500, so it always returns an error.
+func (d *Device) SetSockOpt(int, int, int, any) error {
+	return netdev.ErrNotSupported
+}
+
+// Connect establishes a connection to the specified host and port or ip and port.
+//
+// If the host is an empty string, it will use the provided ip address and port,
+// otherwise it will resolve the host name to an IP address.
+func (d *Device) Connect(sockfd int, host string, ip netip.AddrPort) error {
+	destIP := ip.Addr()
+	if host != "" {
+		var err error
+		destIP, err = d.GetHostByName(host)
+		if err != nil {
+			return errors.New("could not resolve host " + host + ":" + err.Error())
+		}
+	}
+	if !destIP.IsValid() || !destIP.Is4() {
+		return errors.New("invalid destination IP address: " + destIP.String())
+	}
+	port := ip.Port()
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return err
+	}
+
+	d.write(sockDestIP, sockAddr(sock.sockn), destIP.AsSlice())
+	d.writeUint16(sockDestPort, sockAddr(sock.sockn), port)
+	d.socketSendCmd(sock.sockn, sockCmdOpen)
+	return nil
+}
+
+// Listen sets the socket to listen for incoming connections on the specified socket file descriptor.
+//
+// The backlog parameter is ignored, as the W5500 does not support it.
+func (d *Device) Listen(sockfd int, _ int) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return err
+	}
+
+	if sock.protocol != 1 { // Only TCP sockets can listen
+		return errors.New("not a TCP socket")
+	}
+
+	if err = d.listen(sock.sockn); err != nil {
+		return errors.New("could not send listen command: " + err.Error())
+	}
+	return nil
+}
+
+func (d *Device) listen(sockn uint8) error {
+	state := d.sockStatus(sockn)
+	if state != sockStatusInit {
+		return errors.New("socket is not in the initial state")
+	}
+	d.socketSendCmd(sockn, sockCmdListen)
+	return nil
+}
+
+// Accept waits for an incoming connection on the specified socket file descriptor.
+func (d *Device) Accept(sockfd int) (int, netip.AddrPort, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	lsock, err := d.socket(sockfd)
+	if err != nil {
+		return -1, netip.AddrPort{}, errors.New("could not get socket: " + err.Error())
+	}
+
+	if err = d.waitForEstablished(lsock.sockn); err != nil {
+		return -1, netip.AddrPort{}, err
+	}
+
+	// Acquire a new socket for the listening connection.
+	csockfd, csock, err := d.nextSocket()
+	if err != nil {
+		return -1, netip.AddrPort{}, err
+	}
+	// Swap the socket numbers of the client and listening sockets.
+	lsock.sockn, csock.sockn = csock.sockn, lsock.sockn
+
+	// Rebind the listening socket to the local address and port and start listening.
+	d.openSocket(lsock.sockn, lsock.protocol)
+	if err = d.bindSocket(lsock.sockn, lsock.port); err != nil {
+		return -1, netip.AddrPort{}, errors.New("could not bind listening socket: " + err.Error())
+	}
+	if err = d.listen(lsock.sockn); err != nil {
+		return -1, netip.AddrPort{}, errors.New("could not set listening socket: " + err.Error())
+	}
+
+	csock.setInUse(true)
+
+	remoteIP := d.remoteIP(csock.sockn)
+	return csockfd, remoteIP, nil
+}
+
+func (d *Device) waitForEstablished(sockn uint8) error {
+	for {
+		status := d.sockStatus(sockn)
+		switch status {
+		case sockStatusEstablished:
+			return nil
+		case sockStatusClosed:
+			return net.ErrClosed
+		case sockStatusCloseWait:
+			// The server closed the connection, so we need to reset the socket
+			// and set it to listen again.
+			if err := d.listen(sockn); err != nil {
+				return errors.New("could not set socket to listen: " + err.Error())
+			}
+		}
+
+		d.irqPoll(sockn, sockIntConnect|sockIntDisconnect, time.Time{})
+	}
+}
+
+func (d *Device) remoteIP(sockn uint8) netip.AddrPort {
+	var rip [4]byte
+	d.read(sockDestIP, sockAddr(sockn), rip[:])
+
+	var rport [2]byte
+	d.read(sockDestPort, sockAddr(sockn), rport[:])
+
+	return netip.AddrPortFrom(netip.AddrFrom4(rip), uint16(rport[0])<<8|uint16(rport[1]))
+}
+
+// Send sends data to the socket with the given file descriptor.
+// It blocks until all data is sent or the deadline is reached.
+func (d *Device) Send(sockfd int, buf []byte, _ int, deadline time.Time) (int, error) {
+	bufLen := len(buf)
+	if bufLen <= d.maxSockSize {
+		// Fast path for small buffers.
+		return d.sendChunk(sockfd, buf, deadline)
+	}
+
+	var n int
+	for i := 0; i < bufLen; i += d.maxSockSize {
+		end := i + d.maxSockSize
+		if end > bufLen {
+			end = bufLen
+		}
+
+		sent, err := d.sendChunk(sockfd, buf[i:end], deadline)
+		if err != nil {
+			return n, errors.New("could not send chunk: " + err.Error())
+		}
+		n += sent
+	}
+	return n, nil
+}
+
+func (d *Device) sendChunk(sockfd int, buf []byte, deadline time.Time) (int, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return 0, errors.New("could not get socket: " + err.Error())
+	}
+	if sock.closed {
+		return 0, os.ErrClosed
+	}
+
+	bufLen := uint16(len(buf))
+	if err = d.waitForFreeBuffer(sock.sockn, bufLen, deadline); err != nil {
+		return 0, err
+	}
+
+	sendPtr := d.readUint16(sockTXWritePtr, sockAddr(sock.sockn))
+
+	d.write(sendPtr, sock.sockn<<2|0b10, buf)
+	d.writeUint16(sockTXWritePtr, sockAddr(sock.sockn), sendPtr+bufLen)
+	d.writeByte(sockCmd, sockAddr(sock.sockn), sockCmdSend)
+
+	irq := d.irqPoll(sock.sockn, sockIntSendOK|sockIntDisconnect|sockIntTimeout, deadline)
+	switch {
+	case irq == sockIntUnknown:
+		return 0, os.ErrDeadlineExceeded
+	case irq&sockIntDisconnect != 0:
+		sock.setClosed(true)
+		return 0, net.ErrClosed
+	case irq&sockIntTimeout != 0:
+		return 0, netdev.ErrTimeout
+	default:
+		return int(bufLen), nil
+	}
+}
+
+func (d *Device) waitForFreeBuffer(sockn uint8, len uint16, deadline time.Time) error {
+	for {
+		freeSize := d.readUint16(sockTXFreeSize, sockAddr(sockn))
+		if freeSize >= len {
+			return nil
+		}
+
+		if !deadline.IsZero() && time.Now().After(deadline) {
+			return netdev.ErrTimeout
+		}
+
+		status := d.sockStatus(sockn)
+		switch status {
+		case sockStatusEstablished, sockStatusCloseWait:
+		default:
+			return errors.New("socket is not in a valid state for sending data")
+		}
+
+		d.mu.Unlock()
+
+		time.Sleep(time.Millisecond)
+
+		d.mu.Lock()
+	}
+}
+
+// Recv reads data from the socket with the given file descriptor into the provided buffer.
+// It blocks until data is available or the deadline is reached.
+func (d *Device) Recv(sockfd int, buf []byte, _ int, deadline time.Time) (int, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return 0, errors.New("could not get socket: " + err.Error())
+	}
+	if sock.closed {
+		return 0, os.ErrClosed
+	}
+
+	size, err := d.waitForData(sock, deadline)
+	if err != nil {
+		return 0, err
+	}
+
+	recvPtr := d.readUint16(sockRXReadPtr, sockAddr(sock.sockn))
+
+	buf = buf[:min(size, len(buf))]
+	d.read(recvPtr, sock.sockn<<2|0b00011, buf)
+	d.writeUint16(sockRXReadPtr, sockAddr(sock.sockn), recvPtr+uint16(len(buf)))
+	d.socketSendCmd(sock.sockn, sockCmdRecv)
+
+	return len(buf), nil
+}
+
+func (d *Device) waitForData(sock *socket, deadline time.Time) (int, error) {
+	for {
+		recvdSize := d.readUint16(sockRXReceivedSize, sockAddr(sock.sockn))
+		if recvdSize > 0 {
+			return int(recvdSize), nil
+		}
+
+		irq := d.irqPoll(sock.sockn, sockIntReceive|sockIntDisconnect, deadline)
+		switch {
+		case irq == sockIntUnknown:
+			return 0, os.ErrDeadlineExceeded
+		case irq&sockIntDisconnect != 0:
+			sock.setClosed(true)
+			return 0, net.ErrClosed
+		}
+	}
+}
+
+// Close closes the socket with the given file descriptor.
+func (d *Device) Close(sockfd int) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	sock, err := d.socket(sockfd)
+	if err != nil {
+		return err
+	}
+
+	d.socketSendCmd(sock.sockn, sockCmdClose)
+	sock.reset()
+	return nil
+}
+
+func (d *Device) nextSocket() (int, *socket, error) {
+	for i, sock := range d.sockets {
+		if sock.inUse {
+			continue
+		}
+		return i, sock, nil
+	}
+	return -1, nil, netdev.ErrNoMoreSockets
+}
+
+func (d *Device) socket(sockfd int) (*socket, error) {
+	if sockfd < 0 || sockfd >= len(d.sockets) {
+		return nil, netdev.ErrInvalidSocketFd
+	}
+	return d.sockets[sockfd], nil
+}
+
+func (d *Device) socketSendCmd(sockn uint8, cmd byte) {
+	d.writeByte(sockCmd, sockAddr(sockn), cmd)
+	for d.readByte(sockCmd, sockAddr(sockn)) != 0 {
+		runtime.Gosched()
+	}
+}
+
+func (d *Device) sockStatus(sockn uint8) int {
+	return int(d.readByte(sockStatus, sockAddr(sockn)))
+}
+
+func sockAddr(sockn uint8) uint8 {
+	return sockn<<2 | 0b0001
+}

w5500/registers.go

@@ -0,0 +1,88 @@
+package w5500
+
+// Common Registers.
+const (
+	regMode        = 0x0000
+	regGatewayAddr = 0x0001
+	regSubnetMask  = 0x0005
+	regMAC         = 0x0009
+	regIPAddr      = 0x000F
+	regIntLevel    = 0x0013
+	regInt         = 0x0015
+	regIntMask     = 0x0016
+	regSockInt     = 0x0017
+	regSockIntMask = 0x0018
+	regRetryTime   = 0x0019
+	regRetryN      = 0x001B
+	// ... PPP registers, not needed
+	regPHYCfg  = 0x002E
+	regChipVer = 0x0039
+)
+
+// Socket Registers.
+const (
+	sockMode           = 0x0000
+	sockCmd            = 0x0001
+	sockInt            = 0x0002
+	sockStatus         = 0x0003
+	sockSrcPort        = 0x0004
+	sockDestMAC        = 0x0006
+	sockDestIP         = 0x000C
+	sockDestPort       = 0x0010
+	sockMaxSegSize     = 0x0012
+	sockIPTOS          = 0x0015
+	sockIPTTL          = 0x0016
+	sockRXBUFSize      = 0x001E
+	sockTXBUFSize      = 0x001F
+	sockTXFreeSize     = 0x0020
+	sockTXReadPtr      = 0x0022
+	sockTXWritePtr     = 0x0024
+	sockRXReceivedSize = 0x0026
+	sockRXReadPtr      = 0x0028
+	sockRXWritePtr     = 0x002A
+	sockIntMask        = 0x002C
+	sockKeepInt        = 0x002F
+)
+
+// Socket Commands.
+const (
+	sockCmdOpen       = 0x01
+	sockCmdClose      = 0x10
+	sockCmdListen     = 0x02
+	sockCmdConnect    = 0x04
+	sockCmdDisconnect = 0x08
+	sockCmdSend       = 0x20
+	sockCmdSendMacRaw = 0x21
+	sockCmdSendKeep   = 0x22
+	sockCmdRecv       = 0x40
+)
+
+// Socket Statuses.
+const (
+	sockStatusClosed      = 0x00
+	sockStatusInit        = 0x13
+	sockStatusListen      = 0x14
+	sockStatusEstablished = 0x17
+	sockStatusCloseWait   = 0x1C
+	sockStatusUdp         = 0x22
+	sockStatusMacRaw      = 0x42
+	// Temporary TCP states
+	sockStatusSynSent  = 0x15
+	sockStatusSynRecv  = 0x16
+	sockStatusFinWait  = 0x18
+	sockStatusClosing  = 0x1A
+	sockStatusTimeWait = 0x1B
+	sockStatusLastAck  = 0x1D
+	sockStatusUnknown  = 0xFF
+)
+
+// Socket Interrupts.
+const (
+	sockIntConnect uint8 = 1 << iota
+	sockIntDisconnect
+	sockIntReceive
+	sockIntTimeout
+	sockIntSendOK
+
+	sockIntUnknown uint8 = 0
+)

w5500/w5500.go

@@ -0,0 +1,248 @@
+// Package w5500 implements a driver for the W5500 Ethernet controller.
+//
+// The driver supports basic network functionality including TCP and UDP sockets.
+// It currently does not use the IRQ or RST pins.
+//
+// Datasheet: https://docs.wiznet.io/img/products/w5500/W5500_ds_v110e.pdf
+// Product Page: https://wiznet.io/products/ethernet-chips/w5500
+package w5500
+
+import (
+	"errors"
+	"net"
+	"net/netip"
+	"sync"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/pin"
+	"tinygo.org/x/drivers/netdev"
+)
+
+var _ netdev.Netdever = &Device{}
+
+// Resolver is a function that resolves a hostname to an IP address.
+type Resolver func(host string) (netip.Addr, error)
+
+// Device is a driver for the W5500 Ethernet controller.
+type Device struct {
+	maxSockets  int
+	maxSockSize int
+
+	mu  sync.Mutex
+	bus drivers.SPI
+	cs  pin.OutputFunc
+	dns Resolver
+
+	sockets []*socket
+	laddr   netip.Addr
+
+	cmdBuf [3]byte
+}
+
+// New returns a new w5500 driver.
+func New(bus drivers.SPI, csPin pin.Output) *Device {
+	return &Device{
+		bus: bus,
+		cs:  csPin.Set,
+	}
+}
+
+// Config is the configuration for the device.
+//
+// The SPI bus must be fully configured.
+type Config struct {
+	DNS Resolver
+
+	MAC        net.HardwareAddr
+	IP         netip.Addr
+	SubnetMask netip.Addr
+	Gateway    netip.Addr
+
+	// Optional, default is 8.
+	MaxSockets int
+}
+
+// Configure sets up the device.
+//
+// MAC address must be provided. The other fields are optional.
+func (d *Device) Configure(cfg Config) error {
+	d.cs(true)
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.dns = cfg.DNS
+
+	d.reset()
+
+	if err := d.setupSockets(cfg.MaxSockets); err != nil {
+		return errors.New("could not setup sockets: " + err.Error())
+	}
+
+	// Set the MAC address and IP configuration.
+	d.write(regMAC, 0, cfg.MAC)
+	d.write(regIPAddr, 0, cfg.IP.AsSlice())
+	d.write(regSubnetMask, 0, cfg.SubnetMask.AsSlice())
+	d.write(regGatewayAddr, 0, cfg.Gateway.AsSlice())
+	d.laddr = cfg.IP
+
+	return nil
+}
+
+func (d *Device) setupSockets(maxSockets int) error {
+	if maxSockets == 0 {
+		maxSockets = 8 // Default to 8 sockets if not specified.
+	}
+	switch maxSockets {
+	case 1, 2, 4, 8:
+		// Valid socket counts.
+	default:
+		return errors.New("invalid number of sockets, must be one of 1, 2, 4, or 8")
+	}
+
+	socks := make([]*socket, maxSockets)
+	for i := range socks {
+		socks[i] = &socket{
+			sockn: uint8(i),
+		}
+	}
+
+	d.maxSockets = maxSockets
+	d.maxSockSize = 16 * 1024 / maxSockets
+	d.sockets = socks
+
+	// Set the RX and TX buffer sizes for each socket.
+	for i := 0; i < 8; i++ {
+		size := byte(d.maxSockSize >> 10)
+		if i >= maxSockets {
+			size = 0
+		}
+
+		d.writeByte(sockRXBUFSize, sockAddr(uint8(i)), size)
+		d.writeByte(sockTXBUFSize, sockAddr(uint8(i)), size)
+	}
+
+	mask := byte(0b11111111)
+	switch maxSockets {
+	case 1:
+		mask = 0b00000001
+	case 2:
+		mask = 0b00000011
+	case 4:
+		mask = 0b00001111
+	}
+	d.writeByte(regSockIntMask, 0, mask)
+	d.writeByte(regIntMask, 0, 0)
+	return nil
+}
+
+// Reset performs a soft reset.
+func (d *Device) Reset() {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.reset()
+}
+
+func (d *Device) reset() {
+	// RST is bit 7 of regMode.
+	d.writeByte(regMode, 0, 0x80)
+}
+
+// GetHardwareAddr returns the hardware address of the device.
+func (d *Device) GetHardwareAddr() (net.HardwareAddr, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	mac := make([]byte, 6)
+	d.read(regMAC, 0, mac)
+	return mac, nil
+}
+
+// Addr returns the IP address of the device.
+func (d *Device) Addr() (netip.Addr, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	var ip [4]byte
+	d.read(regIPAddr, 0, ip[:])
+	return netip.AddrFrom4(ip), nil
+}
+
+// SetAddr sets the IP address of the device.
+//
+// The IP address must be a valid IPv4 address.
+func (d *Device) SetAddr(ip netip.Addr) error {
+	if err := d.setAddress(regIPAddr, ip); err != nil {
+		return errors.New("could not set IP address: " + err.Error())
+	}
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.laddr = ip
+	return nil
+}
+
+// SetSubnetMask sets the subnet mask of the device.
+//
+// The subnet mask must be a valid IPv4 address.
+// It is not checked if the subnet mask is valid for the device's IP address.
+func (d *Device) SetSubnetMask(mask netip.Addr) error {
+	return d.setAddress(regSubnetMask, mask)
+}
+
+// SetGateway sets the gateway address of the device.
+//
+// The gateway must be a valid IPv4 address.
+// It is not checked if the gateway is in the same subnet as the device.
+func (d *Device) SetGateway(gateway netip.Addr) error {
+	return d.setAddress(regGatewayAddr, gateway)
+}
+
+func (d *Device) setAddress(addr uint16, ip netip.Addr) error {
+	if !ip.IsValid() || !ip.Is4() {
+		return errors.New("invalid IP address: " + ip.String())
+	}
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.write(addr, 0, ip.AsSlice())
+	return nil
+}
+
+// LinkStatus is the link status of the device.
+type LinkStatus = uint8
+
+// LinkStatus values.
+const (
+	LinkStatusDown LinkStatus = iota
+	LinkStatusUp
+)
+
+// LinkStatus returns the current link status of the device.
+func (d *Device) LinkStatus() LinkStatus {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	return d.readByte(regPHYCfg, 0) & 0b00000001
+}
+
+// LinkInfo returns the current link information of the device.
+func (d *Device) LinkInfo() string {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	linkInfo := d.readByte(regPHYCfg, 0) & 0b00000110
+
+	speed := "10Mbps"
+	if linkInfo&0b00000010 != 0 {
+		speed = "100Mbps"
+	}
+	duplex := "Half Duplex"
+	if linkInfo&0b00000100 != 0 {
+		duplex = "Full Duplex"
+	}
+	return speed + " " + duplex
+}