add example usage

* add regmap Device8I2C/SPI types and their methods
* add endianess hint

encoders/quadrature_interrupt.go

@@ -1,4 +1,4 @@
-//go:build tinygo && (rp2040 || stm32 || k210 || esp32c3 || nrf || sam || (avr && (atmega328p || atmega328pb)))
+//go:build tinygo && (rp2040 || rp2350 || stm32 || k210 || esp32c3 || nrf || sam || (avr && (atmega328p || atmega328pb)))
 
 // Implementation based on:
 // https://gist.github.com/aykevl/3fc1683ed77bb0a9c07559dfe857304a

examples/honeyhsc/example.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/honeyhsc"
+)
+
+// Data taken from https://github.com/rodan/honeywell_hsc_ssc_i2c/blob/master/hsc_ssc_i2c.cpp
+// these defaults are valid for the HSCMRNN030PA2A3 chip
+const (
+	i2cAddress = 0x28
+	// 10%
+	outputMinimum = 0x666
+	// 90% of 2^14 - 1
+	outputMax = 0x399A
+	// min is 0 for sensors that give absolute values
+	pressureMin = 0
+	// 30psi (and we want results in millipascals)
+	// pressureMax = 206842.7
+	pressureMax = 206843 * 1000
+)
+
+func main() {
+	bus := machine.I2C0
+	err := bus.Configure(machine.I2CConfig{
+		Frequency: 400_000, // 100kHz minimum and 400kHz I2C maximum clock. 50 to 800 for SPI.
+		SDA:       machine.I2C0_SDA_PIN,
+		SCL:       machine.I2C0_SCL_PIN,
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+	sensor := honeyhsc.NewDevI2C(bus, i2cAddress, outputMinimum, outputMax, pressureMin, pressureMax)
+	for {
+		time.Sleep(time.Second)
+		const measuremask = drivers.Pressure | drivers.Temperature
+		err := sensor.Update(measuremask)
+		if err != nil {
+			println("error updating measurements:", err.Error())
+			continue
+		}
+		P := sensor.Pressure()
+		T := sensor.Temperature()
+		println("pressure:", P, "temperature:", T)
+	}
+}

examples/lis3dh/main.go

@@ -14,9 +14,18 @@ func main() {
 	i2c.Configure(machine.I2CConfig{SCL: machine.SCL1_PIN, SDA: machine.SDA1_PIN})
 
 	accel := lis3dh.New(i2c)
-	accel.Address = lis3dh.Address1 // address on the Circuit Playground Express
-	accel.Configure()
-	accel.SetRange(lis3dh.RANGE_2_G)
+	err := accel.Configure(lis3dh.Config{
+		Address: lis3dh.Address1, // address on the Circuit Playground Express
+	})
+	for err != nil {
+		println("could not configure LIS3DH:", err)
+		time.Sleep(time.Second)
+	}
+	err = accel.SetRange(lis3dh.RANGE_2_G)
+	for err != nil {
+		println("could not set acceleration range:", err)
+		time.Sleep(time.Second)
+	}
 
 	println(accel.Connected())
 

flash/devices.go

@@ -46,6 +46,10 @@ var DefaultDeviceIdentifier = DeviceIdentifierFunc(func(id JedecID) Attrs {
 		return GD25Q16C()
 	case 0xC84017:
 		return GD25Q64C()
+	case 0x856015:
+		return P25Q16H()
+	case 0xEF4014:
+		return W25Q80DV()
 	case 0xEF4015:
 		return W25Q16JVIQ()
 	case 0xEF4016:
@@ -239,6 +243,24 @@ func GD25Q64C() Attrs {
 	}
 }
 
+// Settings for the Puya P25Q16H 2MiB SPI flash.
+// Datasheet: https://files.seeedstudio.com/wiki/github_weiruanexample/Flash_P25Q16H-UXH-IR_Datasheet.pdf
+func P25Q16H() Attrs {
+	return Attrs{
+		TotalSize:           1 << 21, // 2 MiB
+		StartUp:             5000 * time.Microsecond,
+		JedecID:             JedecID{0x85, 0x60, 0x15},
+		MaxClockSpeedMHz:    55,
+		QuadEnableBitMask:   0x02,
+		HasSectorProtection: true,
+		SupportsFastRead:    true,
+		SupportsQSPI:        true,
+		SupportsQSPIWrites:  true,
+		WriteStatusSplit:    true,
+		SingleStatusByte:    false,
+	}
+}
+
 // Settings for the Winbond W25Q16JV-IQ 2MiB SPI flash. Note that JV-IM has a
 // different .memory_type (0x70) Datasheet:
 // https://www.winbond.com/resource-files/w25q16jv%20spi%20revf%2005092017.pdf
@@ -380,6 +402,25 @@ func W25Q80DL() Attrs {
 		TotalSize:           1 << 20, // 1 MiB
 		StartUp:             5000 * time.Microsecond,
 		JedecID:             JedecID{0xEF, 0x60, 0x14},
+		MaxClockSpeedMHz:    80,
+		QuadEnableBitMask:   0x02,
+		HasSectorProtection: false,
+		SupportsFastRead:    true,
+		SupportsQSPI:        true,
+		SupportsQSPIWrites:  false,
+		WriteStatusSplit:    false,
+		SingleStatusByte:    false,
+	}
+}
+
+// Settings for the Winbond W25Q80DV 2MiB SPI flash.
+// Datasheet:
+// https://www.winbond.com/resource-files/w25q80dv%20dl_revh_10022015.pdf
+func W25Q80DV() Attrs {
+	return Attrs{
+		TotalSize:           1 << 21, // 2 MiB
+		StartUp:             5000 * time.Microsecond,
+		JedecID:             JedecID{0xEF, 0x40, 0x14},
 		MaxClockSpeedMHz:    104,
 		QuadEnableBitMask:   0x02,
 		HasSectorProtection: false,

honeyhsc/hsc.go

@@ -0,0 +1,191 @@
+package honeyhsc
+
+import (
+	"errors"
+	"math"
+
+	"tinygo.org/x/drivers"
+)
+
+var (
+	errSensorMissing = errors.New("hsc: not connected")
+	errDiagnostic    = errors.New("hsc: diagnostic error")
+)
+
+const (
+	measuremask  = drivers.Pressure | drivers.Temperature
+	statusMask   = 0b1100_0000
+	statusOffset = 6
+)
+
+// DevI2C is the TruStability® High Accuracy Silicon Ceramic (HSC) Series is a piezoresistive silicon pressure sensor offering a ratiometric
+// analog or digital output for reading pressure over the specified full scale pressure span and temperature range.
+type DevI2C struct {
+	bus drivers.I2C
+	dev
+	addr uint8
+	buf  [6]byte
+}
+
+// NewDevI2C creates and returns a new DevI2C that communicates with an HSC device over the provided I2C bus.
+// Parameters:
+//   - bus: the I2C bus to use.
+//   - addr: the 7-bit I2C address of the sensor.
+//   - outMin, outMax: raw output code range (counts) corresponding to the pressure span. Depends on sensor model.
+//   - pMin, pMax: pressure range endpoints in millipascals (mPa). Depends on sensor model.
+//
+// The returned DevI2C will use these calibration parameters to convert raw bridge counts to pressure.
+func NewDevI2C(bus drivers.I2C, addr, outMin, outMax uint16, pMin, pMax int32) *DevI2C {
+	h := &DevI2C{
+		bus:  bus,
+		addr: uint8(addr),
+		dev: dev{
+			cmin: outMin,
+			cmax: outMax,
+			pmin: pMin,
+			pmax: pMax,
+		},
+	}
+	return h
+}
+
+// ReadTemperature reads and returns the temperature in milliKelvin (mC) from the I2C-attached HSC device.
+// It performs an Update internally to get the latest temperature value.
+func (h *DevI2C) ReadTemperature() (int32, error) {
+	err := h.Update(drivers.Temperature)
+	if err != nil {
+		return 0, err
+	}
+	return h.Temperature(), nil
+}
+
+// Update reads both temperature and pressure data from the I2C-attached HSC device when
+// the requested measurement mask includes pressure or temperature.
+// If neither pressure nor temperature is requested, Update is a no-op.
+func (d *DevI2C) Update(which drivers.Measurement) error {
+	// Update performs an I2C transaction to read 4 bytes, parses the status bits, 14-bit bridge data and
+	// temperature bits, and forwards them to the internal update routine. Any I2C transport error is returned,
+	// as well as errors produced by the internal update (e.g. errSensorMissing, errDiagnostic).
+	if which&measuremask == 0 {
+		return nil
+	}
+	rbuf := d.buf[:4]
+	wbuf := d.buf[4:6]
+	const reg = 0
+	value := (d.addr << 1) | 1
+	wbuf[0] = reg
+	wbuf[1] = value
+	err := d.bus.Tx(uint16(d.addr), wbuf, rbuf)
+	if err != nil {
+		return err
+	}
+	status := (rbuf[0] & statusMask) >> statusOffset
+	bridgeData := (uint16(rbuf[0]&^statusMask) << 8) | uint16(rbuf[1])
+	tempData := uint16(rbuf[2])<<8 | uint16(rbuf[3]&0xe0)>>5
+	return d.dev.update(status, bridgeData, tempData)
+}
+
+type pinout func(level bool)
+
+// DevI2C is the TruStability® High Accuracy Silicon Ceramic (HSC) Series is a piezoresistive silicon pressure sensor offering a ratiometric
+// analog or digital output for reading pressure over the specified full scale pressure span and temperature range.
+type DevSPI struct {
+	spi drivers.SPI
+	cs  pinout
+	dev
+	buf [4]byte
+}
+
+// NewDevSPI creates and returns a new DevSPI that communicates with an HSC device over SPI.
+// Parameters:
+//   - conn: the SPI connection to use.
+//   - cs: a chip-select function that drives the device select line low/high.
+//   - outMin, outMax: raw output code range (counts) corresponding to the pressure span. Depends on sensor model.
+//   - pMin, pMax: pressure range endpoints in millipascals (mPa). Depends on sensor model.
+//
+// The function returns the constructed DevSPI and an error value (currently always nil).
+func NewDevSPI(conn drivers.SPI, cs pinout, outMin, outMax uint16, pMin, pMax int32) (*DevSPI, error) {
+	h := &DevSPI{
+		spi: conn,
+		cs:  cs,
+		dev: dev{
+			cmin: outMin,
+			cmax: outMax,
+			pmin: pMin,
+			pmax: pMax,
+		},
+	}
+	return h, nil
+}
+
+// ReadTemperature reads and returns the temperature in milliKelvin (mC) from the SPI-attached HSC device.
+// It performs an Update internally to get the latest temperature value.
+func (h *DevSPI) ReadTemperature() (int32, error) {
+	err := h.Update(drivers.Temperature)
+	if err != nil {
+		return 0, err
+	}
+	return h.Temperature(), nil
+}
+
+// Update reads pressure and temperature data from the SPI-attached HSC device when the requested measurement mask includes
+// pressure or temperature. If neither pressure nor temperature is requested, Update is a no-op.
+func (h *DevSPI) Update(which drivers.Measurement) error {
+	// It toggles the provided chip-select, performs an SPI transfer to read 4 bytes, parses the status bits,
+	// 14-bit bridge data and temperature bits, and forwards them to the internal update routine. Any SPI
+	// transport error is returned, as well as errors produced by the internal update (e.g. errSensorMissing, errDiagnostic).
+	if which&measuremask == 0 {
+		return nil
+	}
+	buf := &h.buf
+	h.cs(false)
+	err := h.spi.Tx(nil, buf[:4])
+	h.cs(true)
+	if err != nil {
+		return err
+	}
+	// First two bits are status bits.
+	status := (buf[0] & statusMask) >> statusOffset
+	bridgeData := (uint16(buf[0]&^statusMask) << 8) | uint16(buf[1])
+
+	tempData := uint16(buf[2])<<8 | uint16(buf[3]&0xe0)>>5
+	return h.dev.update(status, bridgeData, tempData)
+}
+
+type dev struct {
+	pressure   int32
+	temp       int32
+	cmin, cmax uint16
+	pmin, pmax int32
+}
+
+// Pressure returns the most recently computed pressure value in millipascals (mPa).
+// The value is taken from the last successful Update.
+func (d *dev) Pressure() int32 {
+	return d.pressure
+}
+
+// Temperature returns the most recently read temperature value in milliKelvin (mC).
+// The value is taken from the last successful Update.
+func (d *dev) Temperature() int32 {
+	return d.temp + 273_150
+}
+
+// update interprets raw sensor fields (status, bridgeData, tempData) and updates the dev's stored
+// pressure and temperature. It returns errSensorMissing when the temperature raw value indicates no sensor
+// (tempData == math.MaxUint16), errDiagnostic when the status indicates a device diagnostic condition
+// (status == 3), or nil on success. Pressure is computed with integer arithmetic using the configured
+// cmin/cmax -> pmin/pmax linear mapping in order to avoid overflows.
+func (d *dev) update(status uint8, bridgeData, tempData uint16) error {
+	if tempData == math.MaxUint16 {
+		return errSensorMissing
+	} else if status == 3 {
+		return errDiagnostic
+	}
+
+	// Take care not to overflow here.
+	p := (int32(bridgeData)-int32(d.cmin))*(d.pmax-d.pmin)/int32(d.cmax-d.cmin) + d.pmin
+	d.temp = int32(tempData)
+	d.pressure = p
+	return nil
+}

internal/legacy/pinconfig.go

@@ -0,0 +1,62 @@
+package legacy
+
+import (
+	"errors"
+
+	"tinygo.org/x/drivers/internal/pin"
+)
+
+// The pingconfig group of files serve to abstract away
+// pin configuration calls on the machine.Pin type.
+// It was observed this way of developing drivers was
+// non-portable and unusable on "big" Go projects so
+// future projects should NOT configure pins in driver code.
+// Users must configure pins before passing them as arguments
+// to drivers.
+
+// ConfigurePinOut is a legacy function used to configure pins as outputs.
+//
+// Deprecated: Do not configure pins in drivers.
+// This is a legacy feature and should only be used by drivers that
+// previously configured pins in initialization to avoid breaking users.
+func ConfigurePinOut(po pin.Output) {
+	configurePinOut(po)
+}
+
+// ConfigurePinInput is a legacy function used to configure pins as inputs.
+//
+// Deprecated: Do not configure pins in drivers.
+// This is a legacy feature and should only be used by drivers that
+// previously configured pins in initialization to avoid breaking users.
+func ConfigurePinInputPulldown(pi pin.Input) {
+	configurePinInputPulldown(pi)
+}
+
+// ConfigurePinInput is a legacy function used to configure pins as inputs.
+//
+// Deprecated: Do not configure pins in drivers.
+// This is a legacy feature and should only be used by drivers that
+// previously configured pins in initialization to avoid breaking users.
+func ConfigurePinInput(pi pin.Input) {
+	configurePinInput(pi)
+}
+
+// ConfigurePinInput is a legacy function used to configure pins as inputs.
+//
+// Deprecated: Do not configure pins in drivers.
+// This is a legacy feature and should only be used by drivers that
+// previously configured pins in initialization to avoid breaking users.
+func ConfigurePinInputPullup(pi pin.Input) {
+	configurePinInputPullup(pi)
+}
+
+// PinIsNoPin returns true if the argument is a machine.Pin type and is the machine.NoPin predeclared type.
+//
+// Deprecated: Drivers do not require pin knowledge from now on.
+func PinIsNoPin(pin any) bool {
+	return pinIsNoPin(pin)
+}
+
+var (
+	ErrConfigBeforeInstantiated = errors.New("device must be instantiated with New before calling Configure method")
+)

internal/legacy/pinconfig_go.go

@@ -0,0 +1,15 @@
+//go:build !tinygo
+
+package legacy
+
+import "tinygo.org/x/drivers/internal/pin"
+
+// This file compiles for non-tinygo builds
+// for use with "big" or "upstream" Go where
+// there is no machine package.
+
+func configurePinOut(p pin.Output)          {}
+func configurePinInput(p pin.Input)         {}
+func configurePinInputPulldown(p pin.Input) {}
+func configurePinInputPullup(p pin.Input)   {}
+func pinIsNoPin(a any) bool                 { return false }

internal/legacy/pinconfig_nopulls.go

@@ -0,0 +1,10 @@
+//go:build baremetal && fe310
+
+package legacy
+
+import "machine"
+
+const (
+	pulldown = machine.PinInput
+	pullup   = machine.PinInput
+)

internal/legacy/pinconfig_pulls.go

@@ -0,0 +1,13 @@
+//go:build baremetal && !fe310
+
+package legacy
+
+import "machine"
+
+// If you are getting a build error here you then we missed adding
+// your CPU build tag to the list of CPUs that do not have pulldown/pullups.
+// Add it above and in pinhal_nopulls! You should also add a smoketest for it :)
+const (
+	pulldown = machine.PinInputPulldown
+	pullup   = machine.PinInputPullup
+)

internal/legacy/pinconfig_tinygo.go

@@ -0,0 +1,37 @@
+//go:build baremetal
+
+package legacy
+
+import (
+	"machine"
+
+	"tinygo.org/x/drivers/internal/pin"
+)
+
+func configurePinOut(po pin.Output) {
+	configurePin(po, machine.PinOutput)
+}
+
+func configurePinInputPulldown(pi pin.Input) {
+	configurePin(pi, pulldown) // some chips do not have pull down, in which case pulldown==machine.PinInput.
+}
+
+func configurePinInput(pi pin.Input) {
+	configurePin(pi, machine.PinInput)
+}
+
+func configurePinInputPullup(pi pin.Input) {
+	configurePin(pi, pullup) // some chips do not have pull up, in which case pullup==machine.PinInput.
+}
+
+func pinIsNoPin(a any) bool {
+	p, ok := a.(machine.Pin)
+	return ok && p == machine.NoPin
+}
+
+func configurePin(p any, mode machine.PinMode) {
+	machinePin, ok := p.(machine.Pin)
+	if ok {
+		machinePin.Configure(machine.PinConfig{Mode: mode})
+	}
+}

internal/pin/internalpin.go

@@ -0,0 +1,72 @@
+// package pin implements a TinyGo Pin HAL.
+// It serves to eliminate machine.Pin from driver constructors
+// so that drivers can be used in "big" Go projects where
+// there is no machine package.
+// This file contains both function and interface-style Pin HAL definitions.
+package pin
+
+// OutputFunc is hardware abstraction for a pin which outputs a
+// digital signal (high or low level).
+//
+//	// Code conversion demo: from machine.Pin to pin.OutputFunc
+//	led := machine.LED
+//	led.Configure(machine.PinConfig{Mode: machine.Output})
+//	var pin pin.OutputFunc = led.Set // Going from a machine.Pin to a pin.OutputFunc
+//
+// This is an alternative to [Output] which is an interface type.
+type OutputFunc func(level bool)
+
+// High sets the underlying pin's level to high. This is equivalent to calling PinOutput(true).
+func (setPin OutputFunc) High() {
+	setPin(true)
+}
+
+// Low sets the underlying pin's level to low. This is equivalent to calling PinOutput(false).
+func (setPin OutputFunc) Low() {
+	setPin(false)
+}
+
+// InputFunc is hardware abstraction for a pin which receives a
+// digital signal and reads it (high or low level).
+//
+//	// Code conversion demo: from machine.Pin to pin.InputFunc
+//	input := machine.LED
+//	input.Configure(machine.PinConfig{Mode: machine.PinInputPulldown}) // or use machine.PinInputPullup or machine.Input
+//	var pin pin.InputFunc = input.Get // Going from a machine.Pin to a pin.InputFunc
+//
+// This is an alternative to [Input] which is an interface type.
+type InputFunc func() (level bool)
+
+// // Below is an example on how to define a input/output pin HAL for a
+// // pin that must switch between input and output mode:
+//
+// 	var pinIsOutput bool
+// 	var po PinOutputFunc = func(b bool) {
+// 		if !pinIsOutput {
+// 			pin.Configure(outputMode)
+// 			pinIsOutput = true
+// 		}
+// 		pin.Set(b)
+// 	}
+//
+// 	var pi PinInputFunc = func() bool {
+// 		if pinIsOutput {
+// 			pin.Configure(inputMode)
+// 			pinIsOutput = false
+// 		}
+// 		return pin.Get()
+// 	}
+
+// Output interface represents a pin hardware abstraction layer for a pin that can output a digital signal.
+//
+// This is an alternative to [OutputFunc] abstraction which is a function type.
+type Output interface {
+	Set(level bool)
+}
+
+// Input interface represents a pin hardware abstraction layer for a pin that can read a digital signal.
+//
+// This is an alternative to [InputFunc] abstraction which is a function type.
+type Input interface {
+	Get() (level bool)
+}

internal/regmap/device8.go

@@ -0,0 +1,143 @@
+package regmap
+
+import (
+	"encoding/binary"
+	"io"
+
+	"tinygo.org/x/drivers"
+)
+
+// Device8 implements common logic to most 8-bit peripherals with an I2C or SPI bus.
+// All methods expect the target to support conventional register read and write operations
+// where the first byte sent is the register address being accessed.
+//
+// All methods use an internal buffer and perform no dynamic memory allocation.
+type Device8 struct {
+	buf [10]byte
+}
+
+// clear zeroes Device8's buffers.
+func (d *Device8) clear() {
+	d.buf = [10]byte{}
+}
+
+// I2C methods.
+
+// Read8I2C reads a single byte from register addr of the device at i2cAddr using the provided I2C bus.
+func (d *Device8) Read8I2C(bus drivers.I2C, i2cAddr uint16, addr uint8) (byte, error) {
+	d.buf[0] = addr
+	err := bus.Tx(i2cAddr, d.buf[0:1], d.buf[1:2])
+	return d.buf[1], err
+}
+
+// Read16I2C reads a 16-bit value from register addr of the device at i2cAddr using the provided I2C bus.
+// The byte order is specified by order.
+func (d *Device8) Read16I2C(bus drivers.I2C, i2cAddr uint16, addr uint8, order binary.ByteOrder) (uint16, error) {
+	d.buf[0] = addr
+	err := bus.Tx(i2cAddr, d.buf[0:1], d.buf[1:3])
+	return order.Uint16(d.buf[1:3]), err
+}
+
+// Read32I2C reads a 32-bit value from register addr of the device at i2cAddr using the provided I2C bus.
+// The byte order is specified by order.
+func (d *Device8) Read32I2C(bus drivers.I2C, i2cAddr uint16, addr uint8, order binary.ByteOrder) (uint32, error) {
+	d.buf[0] = addr
+	err := bus.Tx(i2cAddr, d.buf[0:1], d.buf[1:5])
+	return order.Uint32(d.buf[1:5]), err
+}
+
+// ReadDataI2C reads dataLength bytes from register addr of the device at i2cAddr using the provided I2C bus.
+// The data is stored in dataDestination.
+func (d *Device8) ReadDataI2C(bus drivers.I2C, i2cAddr uint16, addr uint8, dataDestination []byte) error {
+	d.buf[0] = addr
+	return bus.Tx(i2cAddr, d.buf[:1], dataDestination)
+}
+
+// Write8I2C writes a single byte value to register addr of the device at i2cAddr using the provided I2C bus.
+func (d *Device8) Write8I2C(bus drivers.I2C, i2cAddr uint16, addr, value uint8) error {
+	d.buf[0] = addr
+	d.buf[1] = value
+	return bus.Tx(i2cAddr, d.buf[:2], nil)
+}
+
+// Write16I2C writes a 16-bit value to register addr of the device at i2cAddr using the provided I2C bus.
+// The byte order is specified by order.
+func (d *Device8) Write16I2C(bus drivers.I2C, i2cAddr uint16, addr uint8, value uint16, order binary.ByteOrder) error {
+	d.buf[0] = addr
+	order.PutUint16(d.buf[1:3], value)
+	return bus.Tx(i2cAddr, d.buf[0:3], nil)
+}
+
+// Write32I2C writes a 32-bit value to register addr of the device at i2cAddr using the provided I2C bus.
+// The byte order is specified by order.
+func (d *Device8) Write32I2C(bus drivers.I2C, i2cAddr uint16, addr uint8, value uint32, order binary.ByteOrder) error {
+	d.buf[0] = addr
+	order.PutUint32(d.buf[1:5], value)
+	return bus.Tx(i2cAddr, d.buf[0:5], nil)
+}
+
+// SPI methods.
+
+// Read8SPI reads a single byte from register addr using the provided SPI bus.
+func (d *Device8) Read8SPI(bus drivers.SPI, addr uint8) (byte, error) {
+	d.clear()
+	d.buf[0] = addr
+	err := bus.Tx(d.buf[0:1], d.buf[1:2]) // We suppose data is returned after first byte in SPI.
+	return d.buf[1], err
+}
+
+// Read16SPI reads a 16-bit value from register addr using the provided SPI bus. The byte order is specified by order.
+func (d *Device8) Read16SPI(bus drivers.SPI, addr uint8, order binary.ByteOrder) (uint16, error) {
+	d.clear()
+	d.buf[0] = addr
+	err := bus.Tx(d.buf[0:3], d.buf[3:6]) // We suppose data is returned after first byte in SPI.
+	return order.Uint16(d.buf[4:6]), err
+}
+
+// Read32SPI reads a 32-bit value from register addr using the provided SPI bus. The byte order is specified by order.
+func (d *Device8) Read32SPI(bus drivers.SPI, addr uint8, order binary.ByteOrder) (uint32, error) {
+	d.clear()
+	d.buf[0] = addr
+	err := bus.Tx(d.buf[0:5], d.buf[5:10]) // We suppose data is returned after first byte in SPI.
+	return order.Uint32(d.buf[6:10]), err
+}
+
+// ReadDataSPI reads data from a 8bit device address. It assumes data at register address is sent back
+// from device after first byte is written as address.
+// It needs the auxiliary buffer length to be large enough to contain both the write and read portions of buffer,
+// so 2*(dataLength+1) < len(auxiliaryBuf) must hold.
+func (d *Device8) ReadDataSPI(bus drivers.SPI, addr uint8, dataLength int, auxiliaryBuf []byte) ([]byte, error) {
+	split := len(auxiliaryBuf) / 2
+	if split < dataLength+1 {
+		return nil, io.ErrShortBuffer
+	}
+
+	wbuf, rbuf := auxiliaryBuf[:split], auxiliaryBuf[split:]
+	wbuf[0] = addr
+	err := bus.Tx(wbuf, rbuf)
+	return rbuf[1:], err
+}
+
+// Write8SPI writes a single byte value to register addr using the provided SPI bus.
+func (d *Device8) Write8SPI(bus drivers.SPI, addr, value uint8) error {
+	d.clear()
+	d.buf[0] = addr
+	d.buf[1] = value
+	return bus.Tx(d.buf[:2], nil)
+}
+
+// Write16SPI writes a 16-bit value to register addr using the provided SPI bus. The byte order is specified by order.
+func (d *Device8) Write16SPI(bus drivers.SPI, addr uint8, value uint16, order binary.ByteOrder) error {
+	d.clear()
+	d.buf[0] = addr
+	order.PutUint16(d.buf[1:3], value)
+	return bus.Tx(d.buf[:3], nil)
+}
+
+// Write32SPI writes a 32-bit value to register addr using the provided SPI bus. The byte order is specified by order.
+func (d *Device8) Write32SPI(bus drivers.SPI, addr uint8, value uint32, order binary.ByteOrder) error {
+	d.clear()
+	d.buf[0] = addr
+	order.PutUint32(d.buf[1:5], value)
+	return bus.Tx(d.buf[:5], nil)
+}

internal/regmap/device8tx.go

@@ -0,0 +1,196 @@
+// 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/i2c-spi.go

@@ -0,0 +1,123 @@
+package regmap
+
+import (
+	"encoding/binary"
+
+	"tinygo.org/x/drivers"
+)
+
+// Device8SPI implements common logic to most 8-bit peripherals with an SPI bus.
+// All methods expect the target to support conventional register read and write operations
+// where the first byte sent is the register address being accessed.
+//
+// All methods use an internal buffer and perform no dynamic memory allocation.
+type Device8SPI struct {
+	bus   drivers.SPI
+	order binary.ByteOrder
+	d     Device8
+}
+
+// SetBus sets the SPI bus and byte order for the Device8SPI.
+//
+// As a hint, most SPI devices use big-endian (MSB) byte order.
+//   - Big endian: A value of 0x1234 is transmitted as 0x12 followed by 0x34.
+//   - Little endian: A value of 0x1234 is transmitted as 0x34 followed by 0x12.
+func (d *Device8SPI) SetBus(bus drivers.SPI, order binary.ByteOrder) {
+	d.bus = bus
+	d.order = order
+}
+
+// Read8 reads a single byte from register addr.
+func (d *Device8SPI) Read8(addr uint8) (byte, error) {
+	return d.d.Read8SPI(d.bus, addr)
+}
+
+// Read16 reads a 16-bit value from register addr.
+func (d *Device8SPI) Read16(addr uint8) (uint16, error) {
+	return d.d.Read16SPI(d.bus, addr, d.order)
+}
+
+// Read32 reads a 32-bit value from register addr.
+func (d *Device8SPI) Read32(addr uint8) (uint32, error) {
+	return d.d.Read32SPI(d.bus, addr, d.order)
+}
+
+// ReadData reads dataLength bytes from register addr. Due to the internal functioning of
+// SPI, an auxiliary buffer must be provided to perform the operation and avoid memory allocation.
+// The returned slice is a subslice of auxBuffer containing the read data.
+func (d *Device8SPI) ReadData(addr uint8, datalength int, auxBuffer []byte) ([]byte, error) {
+	return d.d.ReadDataSPI(d.bus, addr, datalength, auxBuffer)
+}
+
+// Write8 writes a single byte value to register addr.
+func (d *Device8SPI) Write8(addr, value uint8) error {
+	return d.d.Write8SPI(d.bus, addr, value)
+}
+
+// Write16 writes a 16-bit value to register addr.
+func (d *Device8SPI) Write16(addr uint8, value uint16) error {
+	return d.d.Write16SPI(d.bus, addr, value, d.order)
+}
+
+// Write32 writes a 32-bit value to register addr.
+func (d *Device8SPI) Write32(addr uint8, value uint32) error {
+	return d.d.Write32SPI(d.bus, addr, value, d.order)
+}
+
+// Device8I2C implements common logic to most 8-bit peripherals with an I2C bus.
+// All methods expect the target to support conventional register read and write operations
+// where the first byte sent is the register address being accessed.
+//
+// All methods use an internal buffer and perform no dynamic memory allocation.
+type Device8I2C struct {
+	bus     drivers.I2C
+	i2cAddr uint16
+	order   binary.ByteOrder
+	d       Device8
+}
+
+// SetBus sets the I2C bus, device address, and byte order for the Device8I2C.
+//
+// As a hint, most I2C devices use big-endian (MSB) byte order.
+//   - Big endian: A value of 0x1234 is transmitted as 0x12 followed by 0x34.
+//   - Little endian: A value of 0x1234 is transmitted as 0x34 followed by 0x12.
+func (d *Device8I2C) SetBus(bus drivers.I2C, i2cAddr uint16, order binary.ByteOrder) {
+	d.bus = bus
+	d.i2cAddr = i2cAddr
+	d.order = order
+}
+
+// Read8 reads a single byte from register addr.
+func (d *Device8I2C) Read8(addr uint8) (byte, error) {
+	return d.d.Read8I2C(d.bus, d.i2cAddr, addr)
+}
+
+// Read16 reads a 16-bit value from register addr.
+func (d *Device8I2C) Read16(addr uint8) (uint16, error) {
+	return d.d.Read16I2C(d.bus, d.i2cAddr, addr, d.order)
+}
+
+// Read32 reads a 32-bit value from register addr.
+func (d *Device8I2C) Read32(addr uint8) (uint32, error) {
+	return d.d.Read32I2C(d.bus, d.i2cAddr, addr, d.order)
+}
+
+// ReadData reads dataLength bytes from register addr.
+func (d *Device8I2C) ReadData(addr uint8, dataDestination []byte) error {
+	return d.d.ReadDataI2C(d.bus, d.i2cAddr, addr, dataDestination)
+}
+
+// Write8 writes a single byte value to register addr.
+func (d *Device8I2C) Write8(addr, value uint8) error {
+	return d.d.Write8I2C(d.bus, d.i2cAddr, addr, value)
+}
+
+// Write16 writes a 16-bit value to register addr.
+func (d *Device8I2C) Write16(addr uint8, value uint16) error {
+	return d.d.Write16I2C(d.bus, d.i2cAddr, addr, value, d.order)
+}
+
+// Write32 writes a 32-bit value to register addr.
+func (d *Device8I2C) Write32(addr uint8, value uint32) error {
+	return d.d.Write32I2C(d.bus, d.i2cAddr, addr, value, d.order)
+}

internal/regmap/regmap_test.go

@@ -0,0 +1,34 @@
+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)
+}

lis3dh/lis3dh.go

@@ -11,37 +11,57 @@ import (
 // Device wraps an I2C connection to a LIS3DH device.
 type Device struct {
 	bus     drivers.I2C
-	Address uint16
+	address uint16
 	r       Range
+	accel   [6]byte // stored acceleration data (from the Update call)
+}
+
+// Driver configuration, used for the Configure call. All fields are optional.
+type Config struct {
+	Address uint16
 }
 
 // New creates a new LIS3DH 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 {
-	return Device{bus: bus, Address: Address0}
+	return Device{bus: bus, address: Address0}
 }
 
 // Configure sets up the device for communication
-func (d *Device) Configure() {
+func (d *Device) Configure(config Config) error {
+	if config.Address != 0 {
+		d.address = config.Address
+	}
+
 	// enable all axes, normal mode
-	legacy.WriteRegister(d.bus, uint8(d.Address), REG_CTRL1, []byte{0x07})
+	err := legacy.WriteRegister(d.bus, uint8(d.address), REG_CTRL1, []byte{0x07})
+	if err != nil {
+		return err
+	}
 
 	// 400Hz rate
-	d.SetDataRate(DATARATE_400_HZ)
+	err = d.SetDataRate(DATARATE_400_HZ)
+	if err != nil {
+		return err
+	}
 
 	// High res & BDU enabled
-	legacy.WriteRegister(d.bus, uint8(d.Address), REG_CTRL4, []byte{0x88})
+	err = legacy.WriteRegister(d.bus, uint8(d.address), REG_CTRL4, []byte{0x88})
+	if err != nil {
+		return err
+	}
 
 	// get current range
-	d.r = d.ReadRange()
+	d.r, err = d.ReadRange()
+	return err
 }
 
 // Connected returns whether a LIS3DH has been found.
 // It does a "who am I" request and checks the response.
 func (d *Device) Connected() bool {
 	data := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), WHO_AM_I, data)
+	err := legacy.ReadRegister(d.bus, uint8(d.address), WHO_AM_I, data)
 	if err != nil {
 		return false
 	}
@@ -49,46 +69,51 @@ func (d *Device) Connected() bool {
 }
 
 // SetDataRate sets the speed of data collected by the LIS3DH.
-func (d *Device) SetDataRate(rate DataRate) {
+func (d *Device) SetDataRate(rate DataRate) error {
 	ctl1 := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_CTRL1, ctl1)
+	err := legacy.ReadRegister(d.bus, uint8(d.address), REG_CTRL1, ctl1)
 	if err != nil {
-		println(err.Error())
+		return err
 	}
 	// mask off bits
 	ctl1[0] &^= 0xf0
 	ctl1[0] |= (byte(rate) << 4)
-	legacy.WriteRegister(d.bus, uint8(d.Address), REG_CTRL1, ctl1)
+	return legacy.WriteRegister(d.bus, uint8(d.address), REG_CTRL1, ctl1)
 }
 
 // SetRange sets the G range for LIS3DH.
-func (d *Device) SetRange(r Range) {
+func (d *Device) SetRange(r Range) error {
 	ctl := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_CTRL4, ctl)
+	err := legacy.ReadRegister(d.bus, uint8(d.address), REG_CTRL4, ctl)
 	if err != nil {
-		println(err.Error())
+		return err
 	}
 	// mask off bits
 	ctl[0] &^= 0x30
 	ctl[0] |= (byte(r) << 4)
-	legacy.WriteRegister(d.bus, uint8(d.Address), REG_CTRL4, ctl)
+	err = legacy.WriteRegister(d.bus, uint8(d.address), REG_CTRL4, ctl)
+	if err != nil {
+		return err
+	}
 
 	// store the new range
 	d.r = r
+
+	return nil
 }
 
 // ReadRange returns the current G range for LIS3DH.
-func (d *Device) ReadRange() (r Range) {
+func (d *Device) ReadRange() (r Range, err error) {
 	ctl := []byte{0}
-	err := legacy.ReadRegister(d.bus, uint8(d.Address), REG_CTRL4, ctl)
+	err = legacy.ReadRegister(d.bus, uint8(d.address), REG_CTRL4, ctl)
 	if err != nil {
-		println(err.Error())
+		return 0, err
 	}
 	// mask off bits
 	r = Range(ctl[0] >> 4)
 	r &= 0x03
 
-	return r
+	return r, nil
 }
 
 // ReadAcceleration reads the current acceleration from the device and returns
@@ -96,28 +121,17 @@ func (d *Device) ReadRange() (r Range) {
 // and the sensor is not moving the returned value will be around 1000000 or
 // -1000000.
 func (d *Device) ReadAcceleration() (int32, int32, int32, error) {
-	x, y, z := d.ReadRawAcceleration()
-	divider := float32(1)
-	switch d.r {
-	case RANGE_16_G:
-		divider = 1365
-	case RANGE_8_G:
-		divider = 4096
-	case RANGE_4_G:
-		divider = 8190
-	case RANGE_2_G:
-		divider = 16380
-	}
-
-	return int32(float32(x) / divider * 1000000), int32(float32(y) / divider * 1000000), int32(float32(z) / divider * 1000000), nil
+	rawX, rawY, rawZ := d.ReadRawAcceleration()
+	x, y, z := normalizeRange(rawX, rawY, rawZ, d.r)
+	return x, y, z, nil
 }
 
 // ReadRawAcceleration returns the raw x, y and z axis from the LIS3DH
 func (d *Device) ReadRawAcceleration() (x int16, y int16, z int16) {
-	legacy.WriteRegister(d.bus, uint8(d.Address), REG_OUT_X_L|0x80, nil)
+	legacy.WriteRegister(d.bus, uint8(d.address), REG_OUT_X_L|0x80, nil)
 
 	data := []byte{0, 0, 0, 0, 0, 0}
-	d.bus.Tx(d.Address, nil, data)
+	d.bus.Tx(d.address, nil, data)
 
 	x = int16((uint16(data[1]) << 8) | uint16(data[0]))
 	y = int16((uint16(data[3]) << 8) | uint16(data[2]))
@@ -125,3 +139,68 @@ func (d *Device) ReadRawAcceleration() (x int16, y int16, z int16) {
 
 	return
 }
+
+// Update the sensor values of the 'which' parameter. Only acceleration is
+// supported at the moment.
+func (d *Device) Update(which drivers.Measurement) error {
+	if which&drivers.Acceleration != 0 {
+		// Read raw acceleration values and store them in the driver.
+		err := legacy.WriteRegister(d.bus, uint8(d.address), REG_OUT_X_L|0x80, nil)
+		if err != nil {
+			return err
+		}
+		err = d.bus.Tx(d.address, nil, d.accel[:])
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Acceleration returns the last read acceleration in µg (micro-gravity).
+// When one of the axes is pointing straight to Earth and the sensor is not
+// moving the returned value will be around 1000000 or -1000000.
+func (d *Device) Acceleration() (x, y, z int32) {
+	// Extract the raw 16-bit values.
+	rawX := int16((uint16(d.accel[1]) << 8) | uint16(d.accel[0]))
+	rawY := int16((uint16(d.accel[3]) << 8) | uint16(d.accel[2]))
+	rawZ := int16((uint16(d.accel[5]) << 8) | uint16(d.accel[4]))
+
+	// Normalize these values, to be in µg (micro-gravity).
+	return normalizeRange(rawX, rawY, rawZ, d.r)
+}
+
+// Convert raw 16-bit values to normalized 32-bit values while avoiding floats
+// and divisions.
+func normalizeRange(rawX, rawY, rawZ int16, r Range) (x, y, z int32) {
+	// We're going to convert the 16-bit raw values to values in the range
+	// -1000_000..1000_000. For now we're going to assume a range of 16G, we'll
+	// adjust that range later.
+	// The formula is derived as follows, and carefully selected to avoid
+	// overflow and integer divisions (the division will be optimized to a
+	// bitshift):
+	//   x = x * 1000_000      / 2048
+	//   x = x * (1000_000/64) / (2048/64)
+	//   x = x * 15625         / 32
+	x = int32(rawX) * 15625 / 32
+	y = int32(rawY) * 15625 / 32
+	z = int32(rawZ) * 15625 / 32
+
+	// Now we need to normalize the three values, since we assumed 16G before.
+	shift := uint32(0)
+	switch r {
+	case RANGE_16_G:
+		shift = 0
+	case RANGE_8_G:
+		shift = 1
+	case RANGE_4_G:
+		shift = 2
+	case RANGE_2_G:
+		shift = 3
+	}
+	x >>= shift
+	y >>= shift
+	z >>= shift
+
+	return
+}

lsm9ds1/lsm9ds1.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 
 	"tinygo.org/x/drivers"
-	"tinygo.org/x/drivers/internal/legacy"
 )
 
 type AccelRange uint8
@@ -28,7 +27,7 @@ type Device struct {
 	accelMultiplier int32
 	gyroMultiplier  int32
 	magMultiplier   int32
-	buf             [6]uint8
+	buf             [7]uint8 // up to 6 bytes for read + 1 byte for the register address
 }
 
 // Configuration for LSM9DS1 device.
@@ -61,10 +60,15 @@ func New(bus drivers.I2C) *Device {
 // Case of boolean false and error nil means I2C is up,
 // but "who am I" responses have unexpected values.
 func (d *Device) Connected() bool {
-	data1, data2 := d.buf[:1], d.buf[1:2]
-	legacy.ReadRegister(d.bus, d.AccelAddress, WHO_AM_I, data1)
-	legacy.ReadRegister(d.bus, d.MagAddress, WHO_AM_I_M, data2)
-	return data1[0] == 0x68 && data2[0] == 0x3D
+	data, err := d.readBytes(d.AccelAddress, WHO_AM_I, 1)
+	if err != nil || data[0] != 0x68 {
+		return false
+	}
+	data, err = d.readBytes(d.MagAddress, WHO_AM_I_M, 1)
+	if err != nil || data[0] != 0x3D {
+		return false
+	}
+	return true
 }
 
 // ReadAcceleration reads the current acceleration from the device and returns
@@ -72,8 +76,7 @@ func (d *Device) Connected() bool {
 // and the sensor is not moving the returned value will be around 1000000 or
 // -1000000.
 func (d *Device) ReadAcceleration() (x, y, z int32, err error) {
-	data := d.buf[:6]
-	err = legacy.ReadRegister(d.bus, uint8(d.AccelAddress), OUT_X_L_XL, data)
+	data, err := d.readBytes(d.AccelAddress, OUT_X_L_XL, 6)
 	if err != nil {
 		return
 	}
@@ -88,8 +91,7 @@ func (d *Device) ReadAcceleration() (x, y, z int32, err error) {
 // rotation along one axis and while doing so integrate all values over time,
 // you would get a value close to 360000000.
 func (d *Device) ReadRotation() (x, y, z int32, err error) {
-	data := d.buf[:6]
-	err = legacy.ReadRegister(d.bus, uint8(d.AccelAddress), OUT_X_L_G, data)
+	data, err := d.readBytes(d.AccelAddress, OUT_X_L_G, 6)
 	if err != nil {
 		return
 	}
@@ -102,8 +104,7 @@ func (d *Device) ReadRotation() (x, y, z int32, err error) {
 // ReadMagneticField reads the current magnetic field from the device and returns
 // it in nT (nanotesla). 1 G (gauss) = 100_000 nT (nanotesla).
 func (d *Device) ReadMagneticField() (x, y, z int32, err error) {
-	data := d.buf[:6]
-	err = legacy.ReadRegister(d.bus, uint8(d.MagAddress), OUT_X_L_M, data)
+	data, err := d.readBytes(d.MagAddress, OUT_X_L_M, 6)
 	if err != nil {
 		return
 	}
@@ -115,8 +116,7 @@ func (d *Device) ReadMagneticField() (x, y, z int32, err error) {
 
 // ReadTemperature returns the temperature in Celsius milli degrees (°C/1000)
 func (d *Device) ReadTemperature() (t int32, err error) {
-	data := d.buf[:2]
-	err = legacy.ReadRegister(d.bus, uint8(d.AccelAddress), OUT_TEMP_L, data)
+	data, err := d.readBytes(d.AccelAddress, OUT_TEMP_L, 2)
 	if err != nil {
 		return
 	}
@@ -167,20 +167,16 @@ func (d *Device) doConfigure(cfg Configuration) (err error) {
 		d.magMultiplier = 58
 	}
 
-	data := d.buf[:1]
-
 	// Configure accelerometer
 	// Sample rate & measurement range
-	data[0] = uint8(cfg.AccelSampleRate)<<5 | uint8(cfg.AccelRange)<<3
-	err = legacy.WriteRegister(d.bus, d.AccelAddress, CTRL_REG6_XL, data)
+	err = d.writeByte(d.AccelAddress, CTRL_REG6_XL, uint8(cfg.AccelSampleRate)<<5|uint8(cfg.AccelRange)<<3)
 	if err != nil {
 		return
 	}
 
 	// Configure gyroscope
 	// Sample rate & measurement range
-	data[0] = uint8(cfg.GyroSampleRate)<<5 | uint8(cfg.GyroRange)<<3
-	err = legacy.WriteRegister(d.bus, d.AccelAddress, CTRL_REG1_G, data)
+	err = d.writeByte(d.AccelAddress, CTRL_REG1_G, uint8(cfg.GyroSampleRate)<<5|uint8(cfg.GyroRange)<<3)
 	if err != nil {
 		return
 	}
@@ -190,33 +186,44 @@ func (d *Device) doConfigure(cfg Configuration) (err error) {
 	// Temperature compensation enabled
 	// High-performance mode XY axis
 	// Sample rate
-	data[0] = 0b10000000 | 0b01000000 | uint8(cfg.MagSampleRate)<<2
-	err = legacy.WriteRegister(d.bus, d.MagAddress, CTRL_REG1_M, data)
+	err = d.writeByte(d.MagAddress, CTRL_REG1_M, 0b10000000|0b01000000|uint8(cfg.MagSampleRate)<<2)
 	if err != nil {
 		return
 	}
 
 	// Measurement range
-	data[0] = uint8(cfg.MagRange) << 5
-	err = legacy.WriteRegister(d.bus, d.MagAddress, CTRL_REG2_M, data)
+	err = d.writeByte(d.MagAddress, CTRL_REG2_M, uint8(cfg.MagRange)<<5)
 	if err != nil {
 		return
 	}
 
 	// Continuous-conversion mode
 	// https://electronics.stackexchange.com/questions/237397/continuous-conversion-vs-single-conversion-mode
-	data[0] = 0b00000000
-	err = legacy.WriteRegister(d.bus, d.MagAddress, CTRL_REG3_M, data)
+	err = d.writeByte(d.MagAddress, CTRL_REG3_M, 0b00000000)
 	if err != nil {
 		return
 	}
 
 	// High-performance mode Z axis
-	data[0] = 0b00001000
-	err = legacy.WriteRegister(d.bus, d.MagAddress, CTRL_REG4_M, data)
+	err = d.writeByte(d.MagAddress, CTRL_REG4_M, 0b00001000)
 	if err != nil {
 		return
 	}
 
 	return nil
 }
+
+func (d *Device) readBytes(addr, reg, size uint8) ([]byte, error) {
+	d.buf[0] = reg
+	err := d.bus.Tx(uint16(addr), d.buf[0:1], d.buf[1:size+1])
+	if err != nil {
+		return nil, err
+	}
+	return d.buf[1 : size+1], nil
+}
+
+func (d *Device) writeByte(addr, reg, value uint8) error {
+	d.buf[0] = reg
+	d.buf[1] = value
+	return d.bus.Tx(uint16(addr), d.buf[0:2], nil)
+}

uc8151/uc8151.go

@@ -8,10 +8,11 @@ package uc8151 // import "tinygo.org/x/drivers/uc8151"
 import (
 	"errors"
 	"image/color"
-	"machine"
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+	"tinygo.org/x/drivers/internal/pin"
 	"tinygo.org/x/drivers/pixel"
 )
 
@@ -31,10 +32,10 @@ type Config struct {
 
 type Device struct {
 	bus                      drivers.SPI
-	cs                       machine.Pin
-	dc                       machine.Pin
-	rst                      machine.Pin
-	busy                     machine.Pin
+	cs                       pin.OutputFunc
+	dc                       pin.OutputFunc
+	rst                      pin.OutputFunc
+	isBusy                   pin.InputFunc
 	width                    int16
 	height                   int16
 	buffer                   []uint8
@@ -49,17 +50,22 @@ type Device struct {
 type Speed uint8
 
 // New returns a new uc8151 driver. Pass in a fully configured SPI bus.
-func New(bus drivers.SPI, csPin, dcPin, rstPin, busyPin machine.Pin) Device {
-	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	rstPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	busyPin.Configure(machine.PinConfig{Mode: machine.PinInput})
+// Pins passed in must be configured beforehand.
+func New(bus drivers.SPI, csPin, dcPin, rstPin pin.Output, busyPin pin.Input) Device {
+	// For backwards compatibility.
+	// This driver used to configure pins,
+	// so leave in to not break users.
+	// May be removed in future so try not to depend on it!
+	legacy.ConfigurePinOut(csPin)
+	legacy.ConfigurePinOut(dcPin)
+	legacy.ConfigurePinOut(rstPin)
+	legacy.ConfigurePinInput(busyPin)
 	return Device{
-		bus:  bus,
-		cs:   csPin,
-		dc:   dcPin,
-		rst:  rstPin,
-		busy: busyPin,
+		bus:    bus,
+		cs:     csPin.Set,
+		dc:     dcPin.Set,
+		rst:    rstPin.Set,
+		isBusy: busyPin.Get,
 	}
 }
 
@@ -313,14 +319,14 @@ func (d *Device) ClearDisplay() {
 
 // WaitUntilIdle waits until the display is ready
 func (d *Device) WaitUntilIdle() {
-	for !d.busy.Get() {
+	for !d.isBusy() {
 		time.Sleep(10 * time.Millisecond)
 	}
 }
 
 // IsBusy returns the busy status of the display
 func (d *Device) IsBusy() bool {
-	return d.busy.Get()
+	return d.isBusy()
 }
 
 // ClearBuffer sets the buffer to 0xFF (white)