Prepare for release 0.29

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

.github/FUNDING.yml

@@ -0,0 +1,2 @@
+# These are supported funding model platforms
+open_collective: tinygo

CHANGELOG.md

@@ -1,3 +1,40 @@
+0.29.0
+---
+- **new devices**
+    - **epd1in54**
+        - Waveshare 1.54inch B/W e-Paper display (#704)
+    - **touch**
+        - add capacitive touch sensing on normal GPIO pins
+    - **INA219**
+        - I2C INA219 driver (#705)
+    - **pcf8591**
+        - add ADC only implementation for I2C ADC/DAC (#690)
+
+- **enhancements**
+    - **pixel**
+        - add NewImageFromBytes() function to allow creating image from existing slice
+    - **servo**
+        - Add function `SetAngleWithMicroseconds` (#695)
+    - **onewire**
+        - onewire improvements
+    - **ssd1306**
+        - Add function `SetFlip` and `GetFlip` (#702)
+    - **uc8151**
+        - add FillRectangle() and SetScroll() functions to satisfy tinyterm.Displayer interface
+    - **ssd1306**
+        - add FillRectangle() and SetScroll() functions to satisfy tinyterm.Displayer interface
+
+- **bugfixes**
+    - **pixel**
+        - fix Monochrome setPixel
+
+- **docs**
+    - **readme**
+        - discuss need to change variables in examples
+    - **sponsor**
+        - Add sponsor button to key repositories
+
+
 0.28.0
 ---
 - **new devices**

README.md

@@ -16,7 +16,7 @@ go get tinygo.org/x/drivers
 
 ## How to use
 
-Here is an example in TinyGo that uses the BMP180 digital barometer:
+Here is an example in TinyGo that uses the BMP180 digital barometer.  This example should work on any board that supports I2C:
 
 ```go
 package main
@@ -53,6 +53,28 @@ func main() {
 }
 ```
 
+## Examples Using GPIO or SPI 
+
+If compiling these examples directly you are likely to need to make minor changes to the defined variables to map the pins for the board you are using.  For example, this block in main.go:
+
+```golang
+var (
+        spi   = machine.SPI0
+        csPin = machine.D5
+)
+```
+
+It might not be obvious, but you need to change these to match how you wired your specific board.  Constants are [defined for each supported microcontroller](https://tinygo.org/docs/reference/microcontrollers/).  
+
+For example, to change the definitions for use on a Raspberry Pi Pico using typical wiring, you might need to do this:
+
+```golang
+var (
+        spi   = machine.SPI0
+        csPin = machine.GP17
+)
+```
+
 ## Contributing
 
 Your contributions are welcome!

ds18b20/ds18b20.go

@@ -19,7 +19,7 @@ type OneWireDevice interface {
 	Write(uint8)
 	Read() uint8
 	Select([]uint8) error
-	Сrc8([]uint8, int) uint8
+	Сrc8([]uint8) uint8
 }
 
 // Device wraps a connection to an 1-Wire devices.
@@ -69,7 +69,7 @@ func (d Device) ReadTemperatureRaw(romid []uint8) ([]uint8, error) {
 	for i := 0; i < 9; i++ {
 		spb[i] = d.owd.Read()
 	}
-	if d.owd.Сrc8(spb, 8) != spb[8] {
+	if d.owd.Сrc8(spb) != 0 {
 		return nil, errReadTemperature
 	}
 	return spb[:2:2], nil

examples/ina219/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/ina219"
+)
+
+func main() {
+	machine.I2C0.Configure(machine.I2CConfig{})
+
+	dev := ina219.New(machine.I2C0)
+	dev.Configure()
+
+	for {
+		busVoltage, shuntVoltage, current, power, err := dev.Measurements()
+		if err != nil {
+			println("Error reading measurements", err)
+		}
+
+		println("Bus Voltage:", busVoltage, "V")
+		println("Shunt Voltage:", shuntVoltage/100, "mV")
+		println("Current:", current, "mA")
+		println("Power:", power, "mW")
+
+		time.Sleep(10 * time.Millisecond)
+	}
+}

examples/pcf8591/main.go

@@ -0,0 +1,28 @@
+// Connects to a pcf8591 ADC via I2C.
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/pcf8591"
+)
+
+var (
+	i2c = machine.I2C0
+)
+
+func main() {
+	i2c.Configure(machine.I2CConfig{})
+	adc := pcf8591.New(i2c)
+	adc.Configure()
+
+	// get "CH0" aka "machine.ADC" interface to channel 0 from ADC.
+	p := adc.CH0
+
+	for {
+		val := p.Get()
+		println(val)
+		time.Sleep(50 * time.Millisecond)
+	}
+}

examples/touch/capacitive/main.go

@@ -0,0 +1,69 @@
+// Capacitive touch sensing example.
+//
+// This capacitive touch sensor works by charging a normal GPIO pin, then slowly
+// discharging it through a 1MΩ resistor and seeing how long it takes to go from
+// high to low.
+//
+// Use as follows:
+//   - Change touchPin below as needed.
+//   - Connect this pin to some metal surface, like a piece of aluminimum foil.
+//     Make sure this surface is covered (using paper, Scotch tape, etc).
+//   - Also connect this same pin to ground through a 1MΩ resistor.
+//
+// This sensor is very sensitive to noise on the power source, so you should
+// probably try to limit it by running from a battery for example. Especially
+// phone chargers can produce a lot of noise.
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/touch/capacitive"
+)
+
+const touchPin = machine.GP16 // Raspberry Pi Pico
+
+func main() {
+	time.Sleep(time.Second * 2)
+	println("start")
+
+	led := machine.LED
+	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	led.Low()
+
+	// Configure the array of GPIO pins used for capacitive touch sensing.
+	// We're using only one pin.
+	array := capacitive.NewArray([]machine.Pin{touchPin})
+
+	// Use a dynamic threshold, meaning the GPIO pin is automatically calibrated
+	// and re-calibrated to adjust for varying environments (e.g. changing
+	// humidity).
+	array.SetDynamicThreshold(100)
+
+	wasTouching := false
+	for i := uint32(0); ; i++ {
+		// Update the GPIO pin. This must be called very often.
+		array.Update()
+		touching := array.Touching(0)
+
+		// Indicate whether the pin is touched via the LED.
+		led.Set(touching)
+
+		// Print something when the touch state changed.
+		if wasTouching != touching {
+			wasTouching = touching
+			if touching {
+				println("  touch!")
+			} else {
+				println("  release!")
+			}
+		}
+
+		// Print the current value, as a debugging aid. It's not really meant to
+		// be used directly.
+		if i%128 == 32 {
+			println("touch value:", array.RawValue(0))
+		}
+	}
+}

examples/waveshare-epd/epd1in54/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"image/color"
+	"machine"
+
+	"tinygo.org/x/drivers/waveshare-epd/epd1in54"
+	"tinygo.org/x/tinyfont"
+	"tinygo.org/x/tinyfont/gophers"
+)
+
+var (
+	spi0 = machine.SPI0
+	cs   = machine.D10
+	dc   = machine.D9
+	rst  = machine.D6
+	busy = machine.D5
+
+	black = color.RGBA{R: 1, G: 1, B: 1, A: 255}
+)
+
+func main() {
+	display := epd1in54.New(spi0, cs, dc, rst, busy)
+
+	display.LDirInit(epd1in54.Config{})
+	display.Clear()
+	display.ClearBuffer()
+
+	tinyfont.WriteLineRotated(&display, &gophers.Regular58pt, 150, 0, "A B C", black, tinyfont.ROTATION_90)
+	tinyfont.WriteLineRotated(&display, &gophers.Regular58pt, 100, 0, "D E F", black, tinyfont.ROTATION_90)
+	tinyfont.WriteLineRotated(&display, &gophers.Regular58pt, 50, 0, "G H I", black, tinyfont.ROTATION_90)
+	tinyfont.WriteLineRotated(&display, &gophers.Regular58pt, 0, 0, "J K L", black, tinyfont.ROTATION_90)
+
+	display.Display()
+	display.Sleep()
+}

go.mod

@@ -2,8 +2,6 @@ module tinygo.org/x/drivers
 
 go 1.18
 
-replace tinygo.org/x/drivers/mcp9808 => /home/kasterby/Documents/drivers/mcp9808
-
 require (
 	github.com/eclipse/paho.mqtt.golang v1.2.0
 	github.com/frankban/quicktest v1.10.2

ina219/config.go

@@ -0,0 +1,183 @@
+package ina219
+
+type Config struct {
+	// BusVoltageRange sets the bus voltage range.
+	BusVoltageRange BusVoltageRange
+
+	// PGA sets the programmable gain amplifier.
+	PGA PGA
+
+	// BusADC sets the bus ADC resolution.
+	BusADC BusADC
+
+	// ShuntADC sets the shunt ADC resolution.
+	ShuntADC ShuntADC
+
+	// Mode sets the operating mode.
+	Mode Mode
+
+	// Calibration sets the calibration value for the expected
+	// voltage and current values.
+	Calibration Calibration
+
+	// 1000 / uA per bit
+	CurrentDivider float32
+
+	// 1mW per bit
+	PowerMultiplier float32
+}
+
+// RegisterValue returns the register value of the configuration.
+func (c *Config) RegisterValue() uint16 {
+	return c.BusVoltageRange.RegisterValue() |
+		c.PGA.RegisterValue() |
+		c.BusADC.RegisterValue() |
+		c.ShuntADC.RegisterValue() |
+		c.Mode.RegisterValue()
+}
+
+// Generate a new configuration from a register value.
+func NewConfig(config int16, calibration int16) Config {
+	return Config{
+		BusVoltageRange: BusVoltageRange(config >> 13 & 0x1),
+		PGA:             PGA(config >> 11 & 0x3),
+		BusADC:          BusADC(config >> 7 & 0xF),
+		ShuntADC:        ShuntADC(config >> 3 & 0xF),
+		Mode:            Mode(config & 0x7),
+		Calibration:     Calibration(calibration),
+	}
+}
+
+// Configurations from
+// https://github.com/adafruit/Adafruit_INA219/blob/master/Adafruit_INA219.cpp
+var (
+	// Config32V2A is a configuration for a 32V 2A range.
+	Config32V2A = Config{
+		BusVoltageRange: Range32V,
+		PGA:             PGA8,
+		BusADC:          ADC12,
+		ShuntADC:        SADC12,
+		Mode:            ModeContShuntBus,
+		Calibration:     Calibration16V400mA,
+		CurrentDivider:  10.0,
+		PowerMultiplier: 2.0,
+	}
+
+	// Config32V1A is a configuration for a 32V 1A range.
+	Config32V1A = Config{
+		BusVoltageRange: Range32V,
+		PGA:             PGA8,
+		BusADC:          ADC12,
+		ShuntADC:        SADC12,
+		Mode:            ModeContShuntBus,
+		Calibration:     Calibration32V1A,
+		CurrentDivider:  25.0,
+		PowerMultiplier: 0.8,
+	}
+
+	// Config16V400mA is a configuration for a 16V 400mA range.
+	Config16V400mA = Config{
+		BusVoltageRange: Range16V,
+		PGA:             PGA1,
+		BusADC:          ADC12,
+		ShuntADC:        SADC12,
+		Mode:            ModeContShuntBus,
+		Calibration:     Calibration16V400mA,
+		CurrentDivider:  20.0,
+		PowerMultiplier: 1.0,
+	}
+)
+
+// BusVoltageRange is the bus voltage range.
+type BusVoltageRange int8
+
+const (
+	Range16V BusVoltageRange = 0 // 0-16V
+	Range32V BusVoltageRange = 1 // 0-32V
+)
+
+func (r BusVoltageRange) RegisterValue() uint16 {
+	return uint16(r) << 13
+}
+
+// PGA is the programmable gain amplifier.
+type PGA int8
+
+const (
+	PGA1 PGA = 0 // 40mV
+	PGA2 PGA = 1 // 80mV
+	PGA4 PGA = 2 // 160mV
+	PGA8 PGA = 3 // 320mV
+)
+
+func (p PGA) RegisterValue() uint16 {
+	return uint16(p) << 11
+}
+
+// BusADC is the bus ADC resolution.
+type BusADC int8
+
+const (
+	ADC9  BusADC = 0 // 9-bit
+	ADC10 BusADC = 1 // 10-bit
+	ADC11 BusADC = 2 // 11-bit
+	ADC12 BusADC = 3 // 12-bit
+)
+
+func (b BusADC) RegisterValue() uint16 {
+	return uint16(b) << 7
+}
+
+// ShuntADC is the shunt ADC resolution.
+type ShuntADC int8
+
+const (
+	SADC9  ShuntADC = 0 // 9-bit
+	SADC10 ShuntADC = 1 // 10-bit
+	SADC11 ShuntADC = 2 // 11-bit
+	SADC12 ShuntADC = 3 // 12-bit
+)
+
+func (s ShuntADC) RegisterValue() uint16 {
+	return uint16(s) << 3
+}
+
+// Mode is the operating mode.
+type Mode int8
+
+const (
+	ModePowerDown    Mode = 0 // power-down
+	ModeTrigShunt    Mode = 1 // triggered shunt voltage
+	ModeTrigBus      Mode = 2 // triggered bus voltage
+	ModeTrigShuntBus Mode = 3 // triggered shunt and bus voltage
+	ModeADCOff       Mode = 4 // ADC off
+	ModeContShunt    Mode = 5 // continuous shunt voltage
+	ModeContBus      Mode = 6 // continuous bus voltage
+	ModeContShuntBus Mode = 7 // continuous shunt and bus voltage
+)
+
+// ModeTriggered is a mask for triggered modes.
+const ModeTriggeredMask Mode = 0x4
+
+// ModeTriggered returns true if the mode is a triggered mode.
+func ModeTriggered(m Mode) bool {
+	return m != ModePowerDown && m&ModeTriggeredMask == 0
+}
+
+func (m Mode) RegisterValue() uint16 {
+	return uint16(m)
+}
+
+// Calibration is the calibration register for the INA219. Values from:
+// https://github.com/adafruit/Adafruit_INA219/blob/master/Adafruit_INA219.cpp
+type Calibration uint16
+
+const (
+	Calibration32V2A    Calibration = 4096
+	Calibration32V1A    Calibration = 10240
+	Calibration16V400mA Calibration = 8192
+)
+
+func (c Calibration) RegisterValue() uint16 {
+	return uint16(c)
+}

ina219/errors.go

@@ -0,0 +1,13 @@
+package ina219
+
+type ErrOverflow struct{}
+
+func (e ErrOverflow) Error() string { return "overflow" }
+
+type ErrNotReady struct{}
+
+func (e ErrNotReady) Error() string { return "not ready" }
+
+type ErrConfigMismatch struct{}
+
+func (e ErrConfigMismatch) Error() string { return "config mismatch" }

ina219/ina219.go

@@ -0,0 +1,202 @@
+package ina219
+
+import (
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
+)
+
+// An INA219 device.
+type Device struct {
+	bus     drivers.I2C
+	Address uint16
+	config  Config
+}
+
+// Create a new INA219 device with the default configuration
+// and the given I2C bus at the default address.
+//
+// Set Address after New to change the address.
+//
+// Call Configure after New to write the configuration to the
+// device. If you don't call Configure, the device may have a
+// different configuration and the power divider and current
+// multiplier are probably wrong.
+func New(bus drivers.I2C) Device {
+	return Device{
+		bus:     bus,
+		Address: Address,
+		config:  Config32V2A,
+	}
+}
+
+// Set the configuration for the device. This only changes the
+// configuration in memory, not on the device. Call Configure
+// to write the configuration to the device.
+func (d *Device) SetConfig(config Config) {
+	d.config = config
+}
+
+// Write the current configuration to the device.
+func (d *Device) Configure() (err error) {
+	if err = d.WriteRegister(
+		RegConfig,
+		d.config.RegisterValue(),
+	); err != nil {
+		return
+	}
+
+	if err = d.WriteRegister(
+		RegCalibration,
+		d.config.Calibration.RegisterValue(),
+	); err != nil {
+		return
+	}
+
+	var readConfig Config
+	// make sure the configuration is read back correctly
+	if readConfig, err = d.ReadConfig(); err != nil {
+		return
+	} else if readConfig.RegisterValue() != d.config.RegisterValue() {
+		err = ErrConfigMismatch{}
+	} else if readConfig.Calibration.RegisterValue() != d.config.Calibration.RegisterValue() {
+		err = ErrConfigMismatch{}
+	}
+
+	return
+}
+
+// Trigger a conversion. This is only necessary if the device is in
+// trigger mode. In continuous mode (the default), the device will
+// automatically trigger conversions and this has no effect. See
+// config.go.
+//
+// Triggering a conversion or reading the "power" register resets
+// the conversion ready bit.
+func (d *Device) Trigger() (err error) {
+	// Only trigger if the mode is one of the triggered modes.
+	if ModeTriggered(d.config.Mode) {
+		err = d.WriteRegister(RegConfig, d.config.RegisterValue())
+	}
+	return
+}
+
+// Measurements reads the bus voltage, shunt voltage, current, and power
+// from the device.
+func (d *Device) Measurements() (
+	busVoltage int16,
+	shuntVoltage int16,
+	current float32,
+	power float32,
+	err error,
+) {
+	// Attempt to read bus voltage first, so we can check for overflow
+	// or conversion not ready.
+	if busVoltage, err = d.BusVoltage(); err != nil {
+		return
+	}
+
+	// Read the rest of the values, reading Power last, which resets
+	// the conversion ready bit (relevant for triggered modes).
+	if shuntVoltage, err = d.ShuntVoltage(); err != nil {
+		return
+	}
+
+	if current, err = d.Current(); err != nil {
+		return
+	}
+
+	if power, err = d.Power(); err != nil {
+		return
+	}
+
+	return
+}
+
+// BusVoltage reads the "bus" voltage in millivolts.
+//
+// It returns an error if the value is invalid due to overflow
+// or if the conversion is not ready yet. In a continuous mode
+// there should always be a measurement available after the
+// device is ready. See above notes on Trigger.
+func (d *Device) BusVoltage() (voltage int16, err error) {
+	val, err := d.ReadRegister(RegBusVoltage)
+	if err != nil {
+		return
+	}
+
+	// The overflow bit is set, so the values are invalid.
+	if val&(1<<0) != 0 {
+		err = ErrOverflow{}
+		return
+	}
+
+	// The conversion is not ready yet.
+	if ModeTriggered(d.config.Mode) && val&(1<<1) != 0 {
+		err = ErrNotReady{}
+		return
+	}
+
+	voltage = (int16(val) >> 3) * 4
+	return
+}
+
+// ShuntVoltage reads the "shunt" voltage in 100ths of a millivolt.
+func (d *Device) ShuntVoltage() (voltage int16, err error) {
+	return d.ReadRegister(RegShuntVoltage)
+}
+
+// Current reads the current in milliamps.
+func (d *Device) Current() (current float32, err error) {
+	val, err := d.ReadRegister(RegCurrent)
+	if err != nil {
+		return
+	}
+
+	current = float32(val) / d.config.CurrentDivider
+	return
+}
+
+// Power reads the power in milliwatts.
+func (d *Device) Power() (power float32, err error) {
+	val, err := d.ReadRegister(RegPower)
+	if err != nil {
+		return
+	}
+
+	power = float32(val) * d.config.PowerMultiplier
+	return
+}
+
+// Read the configuration from the device.
+func (d *Device) ReadConfig() (config Config, err error) {
+	var cfg, cal int16
+	if cfg, err = d.ReadRegister(RegConfig); err != nil {
+		return
+	}
+
+	if cal, err = d.ReadRegister(RegCalibration); err != nil {
+		return
+	}
+
+	config = NewConfig(cfg, cal)
+	return
+}
+
+// Read a register from the device.
+func (d *Device) ReadRegister(reg uint8) (val int16, err error) {
+	buf := make([]byte, 2)
+
+	err = legacy.ReadRegister(d.bus, uint8(d.Address), reg, buf)
+	if err != nil {
+		return
+	}
+
+	val = int16(buf[0])<<8 | int16(buf[1]&0xff)
+	return
+}
+
+// Write to a register on the device.
+func (d *Device) WriteRegister(reg uint8, val uint16) error {
+	buf := []byte{byte(val >> 8), byte(val & 0xff)}
+	return legacy.WriteRegister(d.bus, uint8(d.Address), reg, buf)
+}

ina219/ina219_test.go

@@ -0,0 +1,232 @@
+package ina219
+
+import (
+	"fmt"
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+	"tinygo.org/x/drivers/tester"
+)
+
+func TestDefaultAddress(t *testing.T) {
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	dev := New(bus)
+	c.Assert(dev.Address, qt.Equals, uint16(Address))
+}
+
+func TestBusVoltage(t *testing.T) {
+	t.Run("valid", func(t *testing.T) {
+		c := qt.New(t)
+		bus := tester.NewI2CBus(c)
+		fake := tester.NewI2CDevice16(c, Address)
+		fake.Registers = map[uint8]uint16{
+			RegBusVoltage: (4200 << 3) / 4, // 4.2V
+		}
+		bus.AddDevice(fake)
+
+		dev := New(bus)
+		voltage, err := dev.BusVoltage()
+		c.Assert(err, qt.IsNil)
+		c.Assert(voltage, qt.Equals, int16(4200))
+	})
+
+	t.Run("overflow", func(t *testing.T) {
+		c := qt.New(t)
+		bus := tester.NewI2CBus(c)
+		fake := tester.NewI2CDevice16(c, Address)
+		fake.Registers = map[uint8]uint16{
+			RegBusVoltage: (1 >> 0), // overflow
+		}
+		bus.AddDevice(fake)
+
+		dev := New(bus)
+		_, err := dev.BusVoltage()
+		c.Assert(err, qt.Not(qt.IsNil))
+		c.Assert(err, qt.ErrorMatches, ErrOverflow{}.Error())
+	})
+
+	t.Run("not ready", func(t *testing.T) {
+		c := qt.New(t)
+		bus := tester.NewI2CBus(c)
+		fake := tester.NewI2CDevice16(c, Address)
+		fake.Registers = map[uint8]uint16{
+			RegBusVoltage: ((4200 << 3) / 4) | (1 << 1), // not ready
+		}
+		bus.AddDevice(fake)
+
+		dev := New(bus)
+		dev.config.Mode = ModeTrigBus
+		_, err := dev.BusVoltage()
+		c.Assert(err, qt.Not(qt.IsNil))
+		c.Assert(err, qt.ErrorMatches, ErrNotReady{}.Error())
+	})
+}
+
+func TestShuntVoltage(t *testing.T) {
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	fake := tester.NewI2CDevice16(c, Address)
+	fake.Registers = map[uint8]uint16{
+		RegShuntVoltage: 0x1234,
+	}
+	bus.AddDevice(fake)
+
+	dev := New(bus)
+	voltage, err := dev.ShuntVoltage()
+	c.Assert(err, qt.IsNil)
+	c.Assert(voltage, qt.Equals, int16(0x1234))
+}
+
+func TestCurrent(t *testing.T) {
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	fake := tester.NewI2CDevice16(c, Address)
+	fake.Registers = map[uint8]uint16{
+		RegCurrent: 420 * 6.9, // 420mA
+	}
+	bus.AddDevice(fake)
+
+	dev := New(bus)
+	dev.config.CurrentDivider = 6.9
+	current, err := dev.Current()
+	c.Assert(err, qt.IsNil)
+	c.Assert(current, qt.Equals, float32(420))
+}
+
+func TestPower(t *testing.T) {
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	fake := tester.NewI2CDevice16(c, Address)
+	fake.Registers = map[uint8]uint16{
+		RegPower: 420 / 0.8, // 420mW
+	}
+	bus.AddDevice(fake)
+
+	dev := New(bus)
+	dev.config.PowerMultiplier = 0.8
+	power, err := dev.Power()
+	c.Assert(err, qt.IsNil)
+	c.Assert(power, qt.Equals, float32(420))
+}
+
+func TestReadConfig(t *testing.T) {
+	// use the default configurations
+	for _, tc := range []Config{
+		Config16V400mA,
+		Config32V2A,
+		Config32V1A,
+	} {
+		n := fmt.Sprintf("%x/%x", tc.RegisterValue(), tc.Calibration.RegisterValue())
+		t.Run(n, func(t *testing.T) {
+			c := qt.New(t)
+			bus := tester.NewI2CBus(c)
+			fake := tester.NewI2CDevice16(c, Address)
+			fake.Registers = map[uint8]uint16{
+				RegConfig:      tc.RegisterValue(),
+				RegCalibration: tc.Calibration.RegisterValue(),
+			}
+			bus.AddDevice(fake)
+
+			dev := New(bus)
+			config, err := dev.ReadConfig()
+			c.Assert(err, qt.IsNil)
+			c.Assert(config.BusADC, qt.Equals, tc.BusADC)
+			c.Assert(config.BusVoltageRange, qt.Equals, tc.BusVoltageRange)
+			c.Assert(config.Calibration, qt.Equals, tc.Calibration)
+			c.Assert(config.Mode, qt.Equals, tc.Mode)
+			c.Assert(config.PGA, qt.Equals, tc.PGA)
+			c.Assert(config.ShuntADC, qt.Equals, tc.ShuntADC)
+		})
+	}
+}
+
+func TestWriteConfig(t *testing.T) {
+	// use the default configurations
+	for _, tc := range []Config{
+		Config16V400mA,
+		Config32V2A,
+		Config32V1A,
+	} {
+		n := fmt.Sprintf("%x/%x", tc.RegisterValue(), tc.Calibration.RegisterValue())
+		t.Run(n, func(t *testing.T) {
+			c := qt.New(t)
+			bus := tester.NewI2CBus(c)
+			fake := tester.NewI2CDevice16(c, Address)
+			bus.AddDevice(fake)
+			fake.Registers = map[uint8]uint16{
+				RegConfig:      0,
+				RegCalibration: 0,
+			}
+
+			dev := New(bus)
+			dev.config = tc
+			err := dev.Configure()
+			c.Assert(err, qt.IsNil)
+			c.Assert(fake.Registers[RegConfig], qt.Equals, tc.RegisterValue())
+			c.Assert(fake.Registers[RegCalibration], qt.Equals, tc.Calibration.RegisterValue())
+		})
+	}
+}
+
+func TestSetConfig(t *testing.T) {
+	for _, tc := range []Config{
+		Config16V400mA,
+		Config32V2A,
+		Config32V1A,
+	} {
+		n := fmt.Sprintf("%x/%x", tc.RegisterValue(), tc.Calibration.RegisterValue())
+		t.Run(n, func(t *testing.T) {
+			c := qt.New(t)
+			bus := tester.NewI2CBus(c)
+			dev := New(bus)
+			dev.SetConfig(tc)
+			c.Assert(dev.config, qt.Equals, tc)
+		})
+	}
+}
+
+func TestTrigger(t *testing.T) {
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	fake := tester.NewI2CDevice16(c, Address)
+	bus.AddDevice(fake)
+	fake.Registers = map[uint8]uint16{
+		RegConfig: Config32V2A.RegisterValue(),
+	}
+
+	dev := New(bus)
+	dev.config = Config32V2A
+	dev.config.Mode = ModeTrigBus
+	err := dev.Trigger()
+	c.Assert(err, qt.IsNil)
+	c.Assert(fake.Registers[RegConfig], qt.Equals, dev.config.RegisterValue())
+}
+
+func TestMeasurements(t *testing.T) {
+	bvVal := int16(4200)
+	svVal := int16(1234)
+	iVal := float32(420)
+	pVal := float32(420)
+
+	c := qt.New(t)
+	bus := tester.NewI2CBus(c)
+	fake := tester.NewI2CDevice16(c, Address)
+	bus.AddDevice(fake)
+	fake.Registers = map[uint8]uint16{
+		RegBusVoltage:   uint16(((4200 << 3) / 4) | (1 << 1)),
+		RegShuntVoltage: uint16(svVal),
+		RegCurrent:      uint16(iVal * Config16V400mA.CurrentDivider),
+		RegPower:        uint16(pVal / Config16V400mA.PowerMultiplier),
+	}
+
+	dev := New(bus)
+	dev.config = Config16V400mA
+	bv, sv, i, p, err := dev.Measurements()
+	c.Assert(err, qt.IsNil)
+	c.Assert(bv, qt.Equals, bvVal)
+	c.Assert(sv, qt.Equals, svVal)
+	c.Assert(i, qt.Equals, iVal)
+	c.Assert(p, qt.Equals, pVal)
+
+}

ina219/registers.go

@@ -0,0 +1,13 @@
+package ina219
+
+// The default I2C address for this device.
+const Address = 0x40
+
+const (
+	RegConfig       uint8 = 0x0
+	RegShuntVoltage uint8 = 0x1
+	RegBusVoltage   uint8 = 0x2
+	RegPower        uint8 = 0x3
+	RegCurrent      uint8 = 0x4
+	RegCalibration  uint8 = 0x5
+)

onewire/onewire.go

@@ -27,8 +27,9 @@ type Config struct{}
 
 // Errors list
 var (
-	errNoPresence  = errors.New("Error: OneWire. No devices on the bus.")
-	errReadAddress = errors.New("Error: OneWire. Read address error: CRC mismatch.")
+	errNoPresence     = errors.New("Error: OneWire. No devices on the bus.")
+	errTooManyDevices = errors.New("Error: OneWire. Too many devices on the bus.")
+	errReadAddress    = errors.New("Error: OneWire. Read address error: CRC mismatch.")
 )
 
 // New creates a new GPIO 1-Wire connection.
@@ -46,7 +47,7 @@ func (d *Device) Configure(config Config) {}
 func (d Device) Reset() error {
 	d.p.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	time.Sleep(480 * time.Microsecond)
-	d.p.Configure(machine.PinConfig{Mode: machine.PinInput})
+	d.p.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 	time.Sleep(70 * time.Microsecond)
 	precence := d.p.Get()
 	time.Sleep(410 * time.Microsecond)
@@ -61,11 +62,11 @@ func (d Device) WriteBit(data uint8) {
 	d.p.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	if data&1 == 1 { // Send '1'
 		time.Sleep(5 * time.Microsecond)
-		d.p.Configure(machine.PinConfig{Mode: machine.PinInput})
+		d.p.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 		time.Sleep(60 * time.Microsecond)
 	} else { // Send '0'
 		time.Sleep(60 * time.Microsecond)
-		d.p.Configure(machine.PinConfig{Mode: machine.PinInput})
+		d.p.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 		time.Sleep(5 * time.Microsecond)
 	}
 }
@@ -82,7 +83,7 @@ func (d Device) Write(data uint8) {
 func (d Device) ReadBit() (data uint8) {
 	d.p.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	time.Sleep(3 * time.Microsecond)
-	d.p.Configure(machine.PinConfig{Mode: machine.PinInput})
+	d.p.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 	time.Sleep(8 * time.Microsecond)
 	if d.p.Get() {
 		data = 1
@@ -111,7 +112,7 @@ func (d Device) ReadAddress() ([]uint8, error) {
 	for i := 0; i < 8; i++ {
 		romid[i] = d.Read()
 	}
-	if d.Сrc8(romid, 7) != romid[7] {
+	if d.Сrc8(romid) != 0 {
 		return nil, errReadAddress
 	}
 	return romid, nil
@@ -187,15 +188,22 @@ func (d Device) Search(cmd uint8) ([][]uint8, error) {
 			}
 			d.WriteBit(bit)
 		}
+		if d.Сrc8(lastAddress) != 0 {
+			continue
+		}
+
 		lastFork = lastZero
 		copy(romIDs[romIndex], lastAddress)
 		romIndex++
+		if romIndex >= 32 {
+			return romIDs, errTooManyDevices
+		}
 	}
 	return romIDs[:romIndex:romIndex], nil
 }
 
 // Crc8 compute a Dallas Semiconductor 8 bit CRC.
-func (d Device) Сrc8(buffer []uint8, size int) (crc uint8) {
+func (_ Device) Сrc8(buffer []uint8) (crc uint8) {
 	// Dow-CRC using polynomial X^8 + X^5 + X^4 + X^0
 	// Tiny 2x16 entry CRC table created by Arjen Lentz
 	// See http://lentz.com.au/blog/calculating-crc-with-a-tiny-32-entry-lookup-table
@@ -205,7 +213,7 @@ func (d Device) Сrc8(buffer []uint8, size int) (crc uint8) {
 		0x00, 0x9D, 0x23, 0xBE, 0x46, 0xDB, 0x65, 0xF8,
 		0x8C, 0x11, 0xAF, 0x32, 0xCA, 0x57, 0xE9, 0x74,
 	}
-	for i := 0; i < size; i++ {
+	for i := 0; i < len(buffer); i++ {
 		crc = buffer[i] ^ crc // just re-using crc as intermediate
 		crc = crc8_table[crc&0x0f] ^ crc8_table[16+((crc>>4)&0x0f)]
 	}

pcf8591/pcf8591.go

@@ -0,0 +1,84 @@
+// Package pcf8591 implements a driver for the PCF8591 Analog to Digital/Digital to Analog Converter.
+//
+// Datasheet: https://www.nxp.com/docs/en/data-sheet/PCF8591.pdf
+package pcf8591 // import "tinygo.org/x/drivers/pcf8591"
+
+import (
+	"machine"
+
+	"errors"
+
+	"tinygo.org/x/drivers"
+)
+
+// Device wraps PCF8591 ADC functions.
+type Device struct {
+	bus     drivers.I2C
+	Address uint16
+	CH0     ADCPin
+	CH1     ADCPin
+	CH2     ADCPin
+	CH3     ADCPin
+}
+
+// ADCPin is the implementation of the ADConverter interface.
+type ADCPin struct {
+	machine.Pin
+	d *Device
+}
+
+// New returns a new PCF8591 driver. Pass in a fully configured I2C bus.
+func New(b drivers.I2C) *Device {
+	d := &Device{
+		bus:     b,
+		Address: defaultAddress,
+	}
+
+	// setup all channels
+	d.CH0 = d.GetADC(0)
+	d.CH1 = d.GetADC(1)
+	d.CH2 = d.GetADC(2)
+	d.CH3 = d.GetADC(3)
+
+	return d
+}
+
+// Configure here just for interface compatibility.
+func (d *Device) Configure() {
+}
+
+// Read analog data from channel
+func (d *Device) Read(ch int) (uint16, error) {
+	if ch < 0 || ch > 3 {
+		return 0, errors.New("invalid channel for pcf8591 Read")
+	}
+
+	return d.GetADC(ch).Get(), nil
+}
+
+// GetADC returns an ADC for a specific channel.
+func (d *Device) GetADC(ch int) ADCPin {
+	return ADCPin{machine.Pin(ch), d}
+}
+
+// Get the current reading for a specific ADCPin.
+func (p ADCPin) Get() uint16 {
+	// TODO: also implement DAC
+	tx := make([]byte, 2)
+	tx[0] = byte(p.Pin)
+
+	rx := make([]byte, 2)
+
+	// The result from the measurement triggered by the first write,
+	// however, the second write is required to get the result.
+	// See section 8.4 "A/D Conversion" in the datasheet for more info
+	p.d.bus.Tx(p.d.Address, tx, rx)
+	p.d.bus.Tx(p.d.Address, tx, rx)
+
+	// scale result to 16bit value like other ADCs
+	return uint16(rx[1]) << 8
+}
+
+// Configure here just for interface compatibility.
+func (p ADCPin) Configure() {
+}

pcf8591/registers.go

@@ -0,0 +1,7 @@
+package pcf8591
+
+// PCF8591 Default Address
+const defaultAddress = 0x48
+
+// control bit for DAC
+const PCF8591_ENABLE_DAC = 0x40

pixel/image.go

@@ -43,6 +43,40 @@ func NewImage[T Color](width, height int) Image[T] {
 	}
 }
 
+// NewImageFromBytes creates a new image of the given size using an existing data slice of bytes.
+func NewImageFromBytes[T Color](width, height int, buf []byte) Image[T] {
+	if width < 0 || height < 0 || int(int16(width)) != width || int(int16(height)) != height {
+		// The width/height are stored as 16-bit integers and should never be
+		// negative.
+		panic("NewImageFromBytes: width/height out of bounds")
+	}
+	var zeroColor T
+	var data unsafe.Pointer
+	switch {
+	case zeroColor.BitsPerPixel()%8 == 0:
+		// Typical formats like RGB888 and RGB565.
+		// Each color starts at a whole byte offset from the start.
+		if len(buf) != width*height*int(unsafe.Sizeof(zeroColor)) {
+			panic("NewImageFromBytes: data slice size mismatch")
+		}
+		data = unsafe.Pointer(&buf[0])
+	default:
+		// Formats like RGB444 that have 12 bits per pixel.
+		// We access these as bytes, so allocate the buffer as a byte slice.
+		bufBits := width * height * zeroColor.BitsPerPixel()
+		bufBytes := (bufBits + 7) / 8
+		if len(buf) != bufBytes {
+			panic("NewImageFromBytes: data slice size mismatch")
+		}
+		data = unsafe.Pointer(&buf[0])
+	}
+	return Image[T]{
+		width:  int16(width),
+		height: int16(height),
+		data:   data,
+	}
+}
+
 // Rescale returns a new Image buffer based on the img buffer.
 // The contents is undefined after the Rescale operation, and any modification
 // to the returned image will overwrite the underlying image buffer in undefined
@@ -104,15 +138,16 @@ func (img Image[T]) setPixel(index int, c T) {
 	switch {
 	case zeroColor.BitsPerPixel() == 1:
 		// Monochrome.
-		x := index % int(img.width)
-		y := index / int(img.width)
-		offset := x + (y/8)*int(img.width)
+		offset := index / 8
+		bits := index % 8
+
 		ptr := (*byte)(unsafe.Add(img.data, offset))
 		if c != zeroColor {
-			*((*byte)(ptr)) |= 1 << uint8(y%8)
+			*((*byte)(ptr)) |= (1 << (7 - uint8(bits)))
 		} else {
-			*((*byte)(ptr)) &^= 1 << uint8(y%8)
+			*((*byte)(ptr)) &^= (1 << (7 - uint8(bits)))
 		}
+
 		return
 	case zeroColor.BitsPerPixel()%8 == 0:
 		// Each color starts at a whole byte offset.
@@ -166,9 +201,10 @@ func (img Image[T]) Get(x, y int) T {
 	case zeroColor.BitsPerPixel() == 1:
 		// Monochrome.
 		var c Monochrome
-		offset := x + (y/8)*int(img.width)
+		offset := index / 8
+		bits := index % 8
 		ptr := (*byte)(unsafe.Add(img.data, offset))
-		c = (*ptr >> uint8(y%8) & 0x1) == 1
+		c = ((*ptr >> (7 - uint8(bits))) & 0x1) > 0
 		return any(c).(T)
 	case zeroColor.BitsPerPixel()%8 == 0:
 		// Colors like RGB565, RGB888, etc.

pixel/image_test.go

@@ -66,9 +66,9 @@ func TestImageRGB444BE(t *testing.T) {
 }
 
 func TestImageMonochrome(t *testing.T) {
-	image := pixel.NewImage[pixel.Monochrome](5, 3)
-	if width, height := image.Size(); width != 5 && height != 3 {
-		t.Errorf("image.Size(): expected 5, 3 but got %d, %d", width, height)
+	image := pixel.NewImage[pixel.Monochrome](128, 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{
 		{R: 0xff, G: 0xff, B: 0xff},
@@ -80,19 +80,101 @@ func TestImageMonochrome(t *testing.T) {
 		{B: 0x00, A: 0xff},
 	} {
 		encoded := pixel.NewColor[pixel.Monochrome](expected.R, expected.G, expected.B)
-		image.Set(4, 2, encoded)
-		actual := image.Get(4, 2).RGBA()
+		image.Set(5, 3, encoded)
+		actual := image.Get(5, 3).RGBA()
 		switch {
-		case expected.R == 0 && expected.G == 0 && expected.B == 0:
-			// should be false eg black
-			if actual.R != 0 || actual.G != 0 || actual.B != 0 {
-				t.Errorf("failed to roundtrip color: expected %v but got %v", expected, actual)
-			}
 		case int(expected.R)+int(expected.G)+int(expected.B) > 128*3:
 			// should be true eg white
 			if actual.R == 0 || actual.G == 0 || actual.B == 0 {
 				t.Errorf("failed to roundtrip color: expected %v but got %v", expected, actual)
 			}
+		default:
+			// should be false eg black
+			if actual.R != 0 || actual.G != 0 || actual.B != 0 {
+				t.Errorf("failed to roundtrip color: expected %v but got %v", expected, actual)
+			}
+		}
+	}
+}
+
+// 128x128
+var rprofile = []byte{
+	0x00, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x44, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00,
+	0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00,
+	0x00, 0x07, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC0, 0x03, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC0, 0x00, 0x00, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF8, 0x0F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0x00,
+	0x00, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xE8, 0x17, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF8, 0x00, 0x07, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC0,
+	0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0x3F, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xFF, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0xBF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x01, 0xF8, 0x00, 0x5F, 0xFF, 0xFF, 0xFC, 0x00, 0x02, 0x80, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x03, 0xFE, 0x03, 0xFF, 0xFD, 0xBF, 0xFF, 0x80, 0x1F, 0xE0, 0x3F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x03, 0xFE, 0x01, 0xFF, 0xF7, 0x6B, 0xFF, 0x80, 0x1F, 0xC0, 0x1F, 0xFF, 0xFE, 0x02, 0xFF, 0xFC, 0x03, 0xDF, 0x17, 0xFA, 0x00, 0x00, 0x37, 0xF0, 0x3F, 0xE0, 0x1F, 0xFF, 0xD0,
+	0x00, 0x07, 0xFC, 0x07, 0x07, 0xBF, 0x00, 0x00, 0x00, 0x01, 0xFE, 0xF8, 0x78, 0x3F, 0xF8, 0x00, 0x00, 0x01, 0xFC, 0x06, 0x1B, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xEA, 0x78, 0x1F, 0x80, 0x00,
+	0x00, 0x01, 0xFC, 0x03, 0x1B, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xE2, 0x68, 0x1F, 0xC0, 0x00, 0x00, 0x01, 0xFC, 0x07, 0x5B, 0xE8, 0x00, 0x00, 0x00, 0x00, 0x07, 0xC4, 0x38, 0x1F, 0x80, 0x00,
+	0x00, 0x01, 0xF8, 0x03, 0x3F, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF7, 0x78, 0x3F, 0xC0, 0x00, 0x00, 0x01, 0xFC, 0x03, 0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0x68, 0x1F, 0x80, 0x00,
+	0x00, 0x01, 0xFC, 0x07, 0x9F, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFC, 0x70, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x03, 0x9E, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x3F, 0x3E, 0xE8, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x01, 0xFF, 0xFF, 0xE0, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xE0, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xF8, 0x01, 0xFF, 0x55, 0xF8, 0x00, 0x00, 0x03, 0xEA, 0xFF, 0xC0, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x01, 0xFE, 0xAF, 0xF0, 0x00, 0x00, 0x03, 0xFD, 0xBF, 0xE0, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x01, 0xF8, 0x00, 0x7C, 0x00, 0x00, 0x07, 0x80, 0x03, 0xE0, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x03, 0xC1, 0xE0, 0x3E, 0x00, 0x00, 0x1F, 0x03, 0xC0, 0xF0, 0x1F, 0x80, 0x00, 0x00, 0x00, 0xF8, 0x07, 0x82, 0xF8, 0x0F, 0x00, 0x00, 0x3E, 0x05, 0xE0, 0x7C, 0x1F, 0x80, 0x00,
+	0x00, 0x01, 0xFC, 0x07, 0x01, 0xF8, 0x17, 0x00, 0x00, 0x3C, 0x09, 0xE0, 0x78, 0x1F, 0xC0, 0x00, 0x00, 0x03, 0xFC, 0x0F, 0x06, 0xFC, 0x07, 0x80, 0x00, 0x7C, 0x1D, 0xE0, 0x3C, 0x1F, 0xC0, 0x00,
+	0x00, 0xFF, 0xFC, 0x1E, 0x03, 0xFC, 0x03, 0x80, 0x00, 0x78, 0x1F, 0xE0, 0x1E, 0x1F, 0xFE, 0x80, 0x2F, 0xFF, 0xFC, 0x1C, 0x07, 0xF8, 0x01, 0x80, 0x00, 0x60, 0x1F, 0xE0, 0x16, 0x1F, 0xFF, 0xF8,
+	0x1F, 0xFF, 0xF8, 0x3E, 0x07, 0xFC, 0x01, 0xC0, 0x00, 0xE8, 0x1F, 0xE0, 0x1E, 0x1F, 0xFF, 0xEC, 0x3F, 0xFF, 0xFC, 0x3C, 0x03, 0xF8, 0x01, 0xC0, 0x00, 0xE0, 0x17, 0xE0, 0x07, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x38, 0x03, 0xE8, 0x00, 0xC0, 0x00, 0xC0, 0x07, 0xC0, 0x03, 0x1F, 0xFF, 0xFC, 0x3F, 0xFF, 0xFC, 0x38, 0x00, 0xC0, 0x00, 0xE0, 0x00, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x78, 0x01, 0xE0, 0x00, 0xC0, 0x00, 0xC0, 0x00, 0x00, 0x03, 0x1F, 0xFF, 0xFC, 0x3F, 0xFF, 0xFC, 0x38, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xF8, 0x78, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x68, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x70, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x01, 0x9F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x78, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x68, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE, 0x3F, 0xFF, 0xF8, 0x70, 0x00, 0x00, 0x00, 0xC0, 0x01, 0xC0, 0x00, 0x00, 0x01, 0x9F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x68, 0x00, 0x00, 0x00, 0xE0, 0x01, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x38, 0x00, 0x00, 0x00, 0xC0, 0x00, 0xC0, 0x00, 0x00, 0x03, 0x9F, 0xFF, 0xFE,
+	0x07, 0xFF, 0xFC, 0x78, 0x00, 0x00, 0x00, 0xC0, 0x80, 0xC0, 0x00, 0x00, 0x03, 0x1F, 0xFF, 0xF8, 0x00, 0x37, 0xF8, 0x38, 0x00, 0x00, 0x01, 0xC7, 0xF0, 0xE0, 0x00, 0x00, 0x03, 0x9F, 0xFE, 0x00,
+	0x00, 0x5F, 0xFC, 0x38, 0x00, 0x00, 0x01, 0xC3, 0xE8, 0xE0, 0x00, 0x00, 0x03, 0x1F, 0xFB, 0x00, 0x00, 0x01, 0xFC, 0x3C, 0x00, 0x00, 0x01, 0xC7, 0xF8, 0xE0, 0x00, 0x00, 0x07, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x3C, 0x00, 0x00, 0x03, 0x9F, 0xFC, 0x70, 0x00, 0x00, 0x07, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xF8, 0x1E, 0x00, 0x00, 0x03, 0xBF, 0xFE, 0x78, 0x00, 0x00, 0x1E, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x1E, 0x00, 0x00, 0x07, 0x9F, 0xFF, 0x78, 0x00, 0x00, 0x16, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x1E, 0x00, 0x00, 0x07, 0x73, 0xC3, 0x3C, 0x00, 0x00, 0x1E, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x1F, 0x00, 0x00, 0x1E, 0x60, 0x01, 0x9E, 0x00, 0x00, 0x3C, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xF8, 0x1F, 0x80, 0x00, 0x7E, 0x40, 0x01, 0x17, 0x80, 0x00, 0x7E, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x1F, 0x80, 0x00, 0x3C, 0x40, 0x01, 0x9F, 0x00, 0x00, 0x7C, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x1F, 0xC0, 0x00, 0xFC, 0x40, 0x01, 0x07, 0xC0, 0x00, 0xFC, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x1F, 0xF8, 0x0B, 0xE8, 0x7B, 0xFF, 0x81, 0xF8, 0x03, 0xFC, 0x1F, 0x80, 0x00, 0x00, 0x03, 0xF8, 0x1C, 0xFF, 0xFF, 0xC0, 0x3F, 0xFE, 0x00, 0xFF, 0xFF, 0xDE, 0x1F, 0xC0, 0x00,
+	0x00, 0x05, 0xFC, 0x1C, 0xFF, 0xFF, 0x80, 0x7F, 0xDE, 0x00, 0xFF, 0x7F, 0xDC, 0x1F, 0x80, 0x00, 0x00, 0xFF, 0xFC, 0x1C, 0x3F, 0xFE, 0x00, 0x0E, 0xB8, 0x00, 0x3F, 0xFF, 0x1C, 0x1F, 0xFC, 0x00,
+	0x2F, 0xFF, 0xF8, 0x1C, 0x00, 0x00, 0x00, 0x04, 0x98, 0x00, 0x01, 0x00, 0x1E, 0x1F, 0xFF, 0xF4, 0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x06, 0x98, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x1C, 0x00, 0x00, 0x00, 0x06, 0x98, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE, 0x7F, 0xFF, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x02, 0xB8, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x1C, 0x00, 0x00, 0x00, 0x03, 0xE8, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE, 0x7F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE, 0x7F, 0xFF, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE, 0x7F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE, 0x7F, 0xFF, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE,
+	0x7F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFE,
+	0x7F, 0xFF, 0xFC, 0x38, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x16, 0x1F, 0xFF, 0xFE, 0x0B, 0xFF, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xF8,
+	0x00, 0x7F, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFE, 0x00, 0x00, 0x01, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xC0, 0x00,
+	0x00, 0x03, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x16, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x38, 0x15, 0xB7, 0x80, 0x00, 0x00, 0x3E, 0x00, 0x00, 0x1C, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xF8, 0x3C, 0x16, 0xAB, 0x00, 0x00, 0x00, 0x52, 0x00, 0x00, 0x16, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x3C, 0x3F, 0xFB, 0x80, 0x00, 0x00, 0xFF, 0x80, 0x00, 0x1C, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x3C, 0x1F, 0xE9, 0x00, 0x00, 0x01, 0xF7, 0x80, 0x00, 0x1E, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xF8, 0x3C, 0x03, 0x82, 0x1D, 0xC6, 0x39, 0xC0, 0x07, 0x00, 0x14, 0x1F, 0xC0, 0x00,
+	0x00, 0x01, 0xFC, 0x3C, 0x03, 0x87, 0x14, 0x85, 0x15, 0xC1, 0x03, 0x80, 0x1E, 0x1F, 0x80, 0x00, 0x00, 0x01, 0xFC, 0x3C, 0x03, 0x87, 0x9F, 0xE6, 0x3D, 0xC0, 0x1F, 0xC0, 0x1C, 0x1F, 0xC0, 0x00,
+	0x00, 0xBF, 0xF8, 0x3C, 0x03, 0x83, 0x9F, 0xE7, 0x3F, 0x8D, 0x1E, 0xC0, 0x16, 0x1F, 0xD4, 0x00, 0x17, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0x9E, 0xE7, 0x79, 0xD7, 0xBC, 0xE0, 0x1C, 0x1F, 0xFF, 0xE8,
+	0x1F, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0x9C, 0xE3, 0x3F, 0x9F, 0xBC, 0xE0, 0x1E, 0x1F, 0xFF, 0xD0, 0x3F, 0xFF, 0xF8, 0x3C, 0x03, 0x83, 0x9E, 0xE7, 0x79, 0xC7, 0xBC, 0xE0, 0x16, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0xBC, 0xE3, 0xF9, 0xC3, 0xBC, 0xE0, 0x1C, 0x1F, 0xFF, 0xFC, 0x3F, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0x9E, 0xEB, 0xE9, 0xE3, 0xBD, 0xE0, 0x1E, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xF8, 0x3C, 0x03, 0x83, 0x9C, 0xE3, 0xF1, 0xC3, 0x9C, 0xC0, 0x1C, 0x1F, 0xFF, 0xFC, 0x3F, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0x9E, 0xE9, 0xE0, 0xFF, 0x9F, 0xC0, 0x16, 0x1F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x03, 0x83, 0xBC, 0x61, 0xE0, 0xFF, 0x07, 0xC0, 0x1E, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x00, 0x00, 0x00, 0x1C, 0x3F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xF8, 0x3C, 0x00, 0x00, 0x00, 0x00, 0xE0, 0x00, 0x00, 0x00, 0x1E, 0x1F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x07, 0xC0, 0x00, 0x00, 0x00, 0x1C, 0x1F, 0xFF, 0xFC,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x17, 0xC0, 0x00, 0x00, 0x00, 0x16, 0x3F, 0xFF, 0xFE, 0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x3F, 0xFF, 0xFE,
+	0x3F, 0xFF, 0xFC, 0x3C, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x1E, 0x3F, 0xFF, 0xFC, 0x3F, 0xFF, 0xFE, 0x3C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1C, 0x7F, 0xFF, 0xFE,
+	0x2F, 0xFF, 0xFF, 0xBC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x80, 0x5F, 0xFF, 0xFF, 0xF8, 0x00, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00,
+	0x01, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xA0, 0x00, 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF0, 0x00,
+	0x00, 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00,
+	0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+}
+
+func TestImageFromBytesMonochrome(t *testing.T) {
+	image := pixel.NewImageFromBytes[pixel.Monochrome](128, 128, rprofile)
+	if width, height := image.Size(); width != 128 && height != 128 {
+		t.Errorf("image.Size(): expected 128, 128 but got %d, %d", width, height)
+	}
+
+	raw := image.RawBuffer()
+	for i, b := range raw {
+		if b != rprofile[i] {
+			t.Fatalf("failed to roundtrip image. expected %v but got %v", rprofile[i], b)
 		}
 	}
 }
@@ -101,22 +183,30 @@ func TestImageMonochrome(t *testing.T) {
 // contain the same data afterwards.
 func TestImageNoise(t *testing.T) {
 	t.Run("RGB888", func(t *testing.T) {
-		testImageNoise[pixel.RGB888](t)
+		testImageNoiseN[pixel.RGB888](t)
 	})
 	t.Run("RGB565BE", func(t *testing.T) {
-		testImageNoise[pixel.RGB565BE](t)
+		testImageNoiseN[pixel.RGB565BE](t)
 	})
 	t.Run("RGB555", func(t *testing.T) {
-		testImageNoise[pixel.RGB555](t)
+		testImageNoiseN[pixel.RGB555](t)
 	})
 	t.Run("RGB444BE", func(t *testing.T) {
-		testImageNoise[pixel.RGB444BE](t)
+		testImageNoiseN[pixel.RGB444BE](t)
 	})
 	t.Run("Monochrome", func(t *testing.T) {
-		testImageNoise[pixel.Monochrome](t)
+		testImageNoiseN[pixel.Monochrome](t)
 	})
 }
 
+// Run the testImageNoise multiple times, because a single test might not catch
+// all bugs (since the test uses random data).
+func testImageNoiseN[T pixel.Color](t *testing.T) {
+	for i := 0; i < 10; i++ {
+		testImageNoise[T](t)
+	}
+}
+
 func testImageNoise[T pixel.Color](t *testing.T) {
 	// Create an image of a random width/height for extra testing.
 	width := rand.Int()%500 + 10

servo/servo.go

@@ -102,3 +102,16 @@ func (s Servo) SetAngle(angle int) error {
 
 	return nil
 }
+
+// SetAngleWithMicroseconds sets the angle of the servo in degrees. The angle should be between
+// 0 and 180, where 0 is the minimum angle and 180 is the maximum angle.
+// The high duration can be customized
+// 0° is lowMicroseconds(us), 180° is highMicroseconds(us)
+func (s Servo) SetAngleWithMicroseconds(angle int, lowMicroseconds, highMicroseconds int) error {
+	if angle < 0 || angle > 180 {
+		return ErrInvalidAngle
+	}
+	microseconds := lowMicroseconds + (highMicroseconds-lowMicroseconds)*angle/180
+	s.SetMicroseconds(int16(microseconds))
+	return nil
+}

smoketest.sh

@@ -73,10 +73,12 @@ tinygo build -size short -o ./build/test.hex -target=microbit ./examples/st7789/
 tinygo build -size short -o ./build/test.hex -target=circuitplay-express ./examples/thermistor/main.go
 tinygo build -size short -o ./build/test.hex -target=circuitplay-bluefruit ./examples/tone
 tinygo build -size short -o ./build/test.hex -target=arduino-nano33 ./examples/tm1637/main.go
+tinygo build -size short -o ./build/test.hex -target=pico ./examples/touch/capacitive
 tinygo build -size short -o ./build/test.hex -target=pyportal ./examples/touch/resistive/fourwire/main.go
 tinygo build -size short -o ./build/test.hex -target=pyportal ./examples/touch/resistive/pyportal_touchpaint/main.go
 tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/vl53l1x/main.go
 tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/vl6180x/main.go
+tinygo build -size short -o ./build/test.hex -target=feather-nrf52840-sense ./examples/waveshare-epd/epd1in54/main.go
 tinygo build -size short -o ./build/test.hex -target=microbit ./examples/waveshare-epd/epd2in13/main.go
 tinygo build -size short -o ./build/test.hex -target=microbit ./examples/waveshare-epd/epd2in13x/main.go
 tinygo build -size short -o ./build/test.hex -target=microbit ./examples/waveshare-epd/epd4in2/main.go
@@ -106,7 +108,9 @@ tinygo build -size short -o ./build/test.hex -target=xiao ./examples/pcf8563/clk
 tinygo build -size short -o ./build/test.hex -target=xiao ./examples/pcf8563/time/
 tinygo build -size short -o ./build/test.hex -target=xiao ./examples/pcf8563/timer/
 tinygo build -size short -o ./build/test.hex -target=pico ./examples/qmi8658c/main.go
+tinygo build -size short -o ./build/test.hex -target=feather-rp2040 ./examples/pcf8591/
 tinygo build -size short -o ./build/test.hex -target=feather-m0 ./examples/ina260/main.go
+tinygo build -size short -o ./build/test.hex -target=feather-m0 ./examples/ina219/main.go
 tinygo build -size short -o ./build/test.hex -target=nucleo-l432kc ./examples/aht20/main.go
 tinygo build -size short -o ./build/test.hex -target=feather-m4 ./examples/sdcard/console/
 tinygo build -size short -o ./build/test.hex -target=feather-m4 ./examples/i2csoft/adt7410/

ssd1306/registers.go

@@ -1,5 +1,7 @@
 package ssd1306
 
+import "tinygo.org/x/drivers"
+
 // Registers
 const (
 	Address        = 0x3D
@@ -38,4 +40,7 @@ const (
 
 	EXTERNALVCC  VccMode = 0x1
 	SWITCHCAPVCC VccMode = 0x2
+
+	NO_ROTATION  = drivers.Rotation0
+	ROTATION_180 = drivers.Rotation180
 )

ssd1306/ssd1306.go

@@ -15,9 +15,8 @@ import (
 )
 
 var (
-	errBufferSize     = errors.New("invalid size buffer")
-	errOutOfRange     = errors.New("out of screen range")
-	errNotImplemented = errors.New("not implemented")
+	errBufferSize = errors.New("invalid size buffer")
+	errOutOfRange = errors.New("out of screen range")
 )
 
 type ResetValue [2]byte
@@ -33,6 +32,7 @@ type Device struct {
 	canReset   bool
 	resetCol   ResetValue
 	resetPage  ResetValue
+	rotation   drivers.Rotation
 }
 
 // Config is the configuration for the display
@@ -48,6 +48,7 @@ type Config struct {
 	// If you're using a different size, you might need to set these values manually.
 	ResetCol  ResetValue
 	ResetPage ResetValue
+	Rotation  drivers.Rotation
 }
 
 type I2CBus struct {
@@ -149,8 +150,8 @@ func (d *Device) Configure(cfg Config) {
 	}
 	d.Command(MEMORYMODE)
 	d.Command(0x00)
-	d.Command(SEGREMAP | 0x1)
-	d.Command(COMSCANDEC)
+
+	d.SetRotation(cfg.Rotation)
 
 	if (d.width == 128 && d.height == 64) || (d.width == 64 && d.height == 48) { // 128x64 or 64x48
 		d.Command(SETCOMPINS)
@@ -363,13 +364,25 @@ func (d *Device) DrawBitmap(x, y int16, bitmap pixel.Image[pixel.Monochrome]) er
 
 // Rotation returns the currently configured rotation.
 func (d *Device) Rotation() drivers.Rotation {
-	return drivers.Rotation0
+	return d.rotation
 }
 
 // SetRotation changes the rotation of the device (clock-wise).
-// Would have to be implemented in software for this device.
 func (d *Device) SetRotation(rotation drivers.Rotation) error {
-	return errNotImplemented
+	d.rotation = rotation
+	switch d.rotation {
+	case drivers.Rotation0:
+		d.Command(SEGREMAP | 0x1) // Reverse horizontal mapping
+		d.Command(COMSCANDEC)     // Reverse vertical mapping
+	case drivers.Rotation180:
+		d.Command(SEGREMAP)   // Normal horizontal mapping
+		d.Command(COMSCANINC) // Normal vertical mapping
+	// nothing to do
+	default:
+		d.Command(SEGREMAP | 0x1) // Reverse horizontal mapping
+		d.Command(COMSCANDEC)     // Reverse vertical mapping
+	}
+	return nil
 }
 
 // Set the sleep mode for this display. When sleeping, the panel uses a lot
@@ -383,3 +396,31 @@ func (d *Device) Sleep(sleepEnabled bool) error {
 	}
 	return nil
 }
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	dw, dh := d.Size()
+
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= d.width || (x+width) > dw || y >= dh || (y+height) > dh {
+		return errOutOfRange
+	}
+
+	if x+width == dw && y+height == dh && c.R == 0 && c.G == 0 && c.B == 0 {
+		d.ClearDisplay()
+		return nil
+	}
+
+	for i := x; i < x+width; i++ {
+		for j := y; j < y+height; j++ {
+			d.SetPixel(i, j, c)
+		}
+	}
+
+	return nil
+}
+
+// SetScroll sets the vertical scrolling for the display, which is a NOP for this display.
+func (d *Device) SetScroll(line int16) {
+	return
+}

touch/capacitive/gpio.go

@@ -0,0 +1,313 @@
+package capacitive
+
+import (
+	"machine"
+	"runtime/interrupt"
+	"time"
+)
+
+const (
+	// How often to measure.
+	// The Update function will wait until this amount of time has passed.
+	measurementFrequency       = 200
+	minTimeBetweenMeasurements = time.Second / measurementFrequency
+
+	// How much to multiply values before averaging. A value higher than 1 will
+	// help to avoid integer rounding errors and may improve accuracy slightly.
+	oversampling = 8
+
+	// How many samples to use for the moving average.
+	movingAverageWindow = 16
+
+	// After how many samples should the touch sensor be recalibrated?
+	// This should be a power of two (for efficient division) and be a multiple
+	// of movingAverageWindow. Ideally it should cause a recalibration every 5s
+	// or so.
+	recalibrationSamples = 1024
+)
+
+type Array struct {
+	// Time when the last update finished. This is used to make sure we call
+	// Update() the expected number of times per second.
+	lastUpdate time.Time
+
+	// List of pins to measure each time.
+	pins []machine.Pin
+
+	// Raw values (non-smoothed) from the last read.
+	values []uint16
+
+	hasFirstMeasurement bool
+
+	// Static threshold. Zero if using a dynamic threshold.
+	staticThreshold uint16
+
+	// How long to measure.
+	measureCycles uint16
+
+	// Sensitivity (in promille) for the dynamic threshold.
+	sensitivity uint16
+
+	// Capacitance trackers for dynamic capacitance measurement.
+	trackers []capacitanceTracker
+}
+
+// Create a new array of pins to be used as touch sensors.
+// The pins do not need to be initialized. The array is immediately ready to
+// use.
+//
+// By default, NewArray configures a static threshold that is not very
+// sensitive. If you want the touch inputs to be more sensitive, use
+// SetDynamicThreshold.
+func NewArray(pins []machine.Pin) *Array {
+	for _, pin := range pins {
+		pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+		pin.High()
+	}
+	array := &Array{
+		pins:          pins,
+		values:        make([]uint16, len(pins)),
+		measureCycles: uint16(machine.CPUFrequency() / 125000), // 1000 on the RP2040 (which is 125MHz)
+		lastUpdate:    time.Now(),
+	}
+
+	// A threshold of 500 works well on the RP2040. Scale this number to
+	// something similar on other chips.
+	array.SetStaticThreshold(int(machine.CPUFrequency() / 250000))
+
+	return array
+}
+
+// Use a static threshold. This works well on simple touch surfaces where you'll
+// directly touch the metal.
+func (a *Array) SetStaticThreshold(threshold int) {
+	if threshold > 0xffff {
+		threshold = 0xffff
+	}
+	a.staticThreshold = uint16(threshold)
+	a.trackers = nil
+}
+
+// Use a dynamic threshold (as promille), that will calibrate automatically.
+// This is needed when you want to be able to detect touches through a
+// non-conducting surface for example. Something like 100‰ (10%) will probably
+// work in many cases, though you may need to try different value to reliably
+// detect touches.
+func (a *Array) SetDynamicThreshold(sensitivity int) {
+	a.sensitivity = uint16(sensitivity)
+	a.staticThreshold = 0
+	a.trackers = make([]capacitanceTracker, len(a.pins))
+}
+
+// Measure all GPIO pins. This function must be called very often, ideally about
+// 100-200 times per second (it will delay a bit when called more than 200 times
+// per second).
+func (a *Array) Update() {
+	// Wait until enough time has passed to charge all pins.
+	now := time.Now()
+	timeSinceLastUpdate := now.Sub(a.lastUpdate)
+	sleepTime := minTimeBetweenMeasurements - timeSinceLastUpdate
+	time.Sleep(sleepTime)
+	a.lastUpdate = now.Add(sleepTime) // should be ~equivalent to time.Now()
+
+	// Measure each pin in turn.
+	for i, pin := range a.pins {
+		// Interrupts must be disabled during measuring for accurate results.
+		mask := interrupt.Disable()
+
+		// Switch to input. This will stop the charging, and let it discharge
+		// through the resistor.
+		pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+
+		// Wait for the pin to go low again.
+		// A longer duration means more capacitance, which means something is
+		// touching it (finger, banana, etc).
+		count := uint32(i)
+		for i := 0; i < int(a.measureCycles); i++ {
+			if !pin.Get() {
+				break
+			}
+			count++
+		}
+
+		interrupt.Restore(mask)
+
+		a.values[i] = uint16(count)
+
+		// Set the pin to high, to charge it for the next measurement.
+		pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+		pin.High()
+	}
+
+	// The first measurement tends to be slightly off (too low value) so ignore
+	// that one.
+	if !a.hasFirstMeasurement {
+		a.hasFirstMeasurement = true
+		return
+	}
+
+	for i := 0; i < len(a.trackers); i++ {
+		a.trackers[i].addValue(int(a.values[i]), int(a.sensitivity))
+	}
+}
+
+// Return the raw value of the given pin index of the most recent call to
+// Update. This value is not smoothed in any way.
+func (a *Array) RawValue(index int) int {
+	return int(a.values[index])
+}
+
+// Return the value from the moving average. This value is only available when a
+// dynamic threshold has been set, it will panic otherwise.
+func (a *Array) SmoothedValue(index int) int {
+	return int(a.trackers[index].avg) / oversampling
+}
+
+// Return whether the given pin index is currently being touched.
+func (a *Array) Touching(index int) bool {
+	if a.staticThreshold != 0 {
+		// Using a static threshold.
+		return a.values[index] > a.staticThreshold
+	}
+
+	return a.trackers[index].touching
+}
+
+// Separate object to store calibration data and track capacitance over time.
+type capacitanceTracker struct {
+	recentValues [movingAverageWindow]uint16
+	sum          uint32
+	avg          uint16
+
+	baseline   uint16
+	noise      uint16
+	valueCount uint8
+	touching   bool
+
+	recalibrationCount    uint8
+	recalibrationPrevAvg  uint16
+	recalibrationNoiseSum int32
+	recalibrationSum      uint32
+}
+
+func (ct *capacitanceTracker) addValue(value int, sensitivity int) {
+	// Maybe increase the resolution slightly by oversampling. This should
+	// increase the resolution a little bit after averaging and should reduce
+	// rounding errors.
+	// Typical input values on the RP2040 are 100-200 (or up to 1000 or so when
+	// touching the metal) so multiplying by 4-8 should be fine. Other chips
+	// generally have much lower values.
+	value *= oversampling
+	if value > 0xffff {
+		value = 0xffff // unlikely, but make sure we don't overflow
+	}
+
+	// This does a number of things at the same time:
+	//  * Add the new value to the recentValues array.
+	//  * Calculate the moving sum (and average) of recentValues using a
+	//    recursive moving average algorithm:
+	//    https://www.dspguide.com/ch15/5.htm
+	ptr := &ct.recentValues[ct.valueCount%movingAverageWindow]
+	ct.sum -= uint32(*ptr)
+	ct.sum += uint32(value)
+	ct.avg = uint16(ct.sum / movingAverageWindow)
+	*ptr = uint16(value)
+	ct.valueCount++
+
+	// Do an initial calibration once the first values have been read.
+	if ct.baseline == 0 && ct.valueCount == movingAverageWindow {
+		ct.baseline = ct.avg
+
+		// Calculate initial noise as an average absolute deviation:
+		// https://en.wikipedia.org/wiki/Average_absolute_deviation
+		// This is a quick and imprecise way to find the noise, better noise
+		// detection happens during recalibration.
+		var diffSum uint32
+		for _, sample := range ct.recentValues {
+			diff := int(ct.avg) - int(sample)
+			if diff < 0 {
+				diff = -diff
+			}
+			diffSum += uint32(diff)
+		}
+		ct.noise = uint16(diffSum / (movingAverageWindow / 2))
+	}
+
+	// Now determine whether the touch pad is being touched.
+
+	if ct.baseline == 0 {
+		// Not yet calibrated.
+		ct.touching = false
+		return
+	}
+
+	// Calculate the threshold.
+	// Divide by 65536 (instead of 65500) to avoid a potentially expensive
+	// division while still being close enough.
+	threshold := (uint32(ct.baseline) * uint32(sensitivity+1000) * 65) / 65536
+
+	// Add noise to the threshold, to avoid toggling quickly. This mainly
+	// filters out mains noise.
+	threshold += uint32(ct.noise)
+
+	// Implement some hysteresis: if the touch pad was previously touched, lower
+	// the threshold a little to avoid bouncing effects.
+	// TODO: let this hysteresis depend on the amount of noise.
+	if ct.touching {
+		threshold = (threshold*3 + uint32(ct.baseline)) / 4 // lower the threshold by 25%
+	}
+
+	// Is the pad being touched?
+	ct.touching = uint32(ct.avg) > threshold
+
+	// Do a recalibration after the sensor hasn't been touched for ~5s, to
+	// account for drift over time (humidity etc).
+	if ct.touching {
+		// Reset calibration (start from zero).
+		ct.recalibrationCount = 0
+		ct.recalibrationSum = 0
+		ct.recalibrationNoiseSum = 0
+	} else {
+		// Add the last batch of samples to the sum.
+		if ct.valueCount%movingAverageWindow == 0 {
+			ct.recalibrationCount++
+
+			// Wait a few cycles before starting data collection for
+			// calibration.
+			cycle := int(ct.recalibrationCount) - 3
+
+			if cycle < 0 {
+				// Store the previous average, to calculate the noise value.
+				ct.recalibrationPrevAvg = ct.avg
+
+			} else if cycle >= 0 {
+				// Collect data for recalibration.
+				ct.recalibrationSum += ct.sum
+
+				// Add difference between two (averaged) samples as a measure of
+				// the noise.
+				diff := int32(ct.recalibrationPrevAvg) - int32(ct.avg)
+				if diff < 0 {
+					diff = -diff
+				}
+				ct.recalibrationNoiseSum += diff
+				ct.recalibrationPrevAvg = ct.avg
+
+			}
+
+			// Do the recalibration after enough samples have been collected.
+			// Note: the noise is basically the average of absolute differences
+			// between two averaging windows. I don't know whether this
+			// algorithm has a name, but it seems to work here to detect the
+			// amount of noise.
+			const totalRecalibrationCount = recalibrationSamples / movingAverageWindow
+			if cycle == totalRecalibrationCount {
+				ct.baseline = uint16(ct.recalibrationSum / recalibrationSamples)
+				ct.noise = uint16(ct.recalibrationNoiseSum / (totalRecalibrationCount / 2))
+				ct.recalibrationCount = 0
+				ct.recalibrationSum = 0
+				ct.recalibrationNoiseSum = 0
+			}
+		}
+	}
+}

uc8151/uc8151.go

@@ -478,3 +478,31 @@ func (d *Device) SetLUT(speed Speed, flickerFree bool) error {
 
 	return nil
 }
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	dw, dh := d.Size()
+
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= d.width || (x+width) > dw || y >= dh || (y+height) > dh {
+		return errOutOfRange
+	}
+
+	if x+width == dw && y+height == dh && c.R == 0 && c.G == 0 && c.B == 0 {
+		d.ClearDisplay()
+		return nil
+	}
+
+	for i := x; i < x+width; i++ {
+		for j := y; j < y+height; j++ {
+			d.SetPixel(i, j, c)
+		}
+	}
+
+	return nil
+}
+
+// SetScroll sets the vertical scrolling for the display, which is a NOP for this display.
+func (d *Device) SetScroll(line int16) {
+	return
+}

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 = "0.28.0"
+const Version = "0.29.0"

waveshare-epd/epd1in54/epd1in54.go

@@ -0,0 +1,424 @@
+// Package epd1in54 implements a driver for Waveshare 1.54in black and white e-paper device.
+//
+// Derived from:
+//
+//	https://github.com/tinygo-org/drivers/tree/master/waveshare-epd
+//	https://github.com/waveshare/e-Paper/blob/master/Arduino/epd1in54_V2/epd1in54_V2.cpp
+//
+// Datasheet: https://www.waveshare.com/w/upload/e/e5/1.54inch_e-paper_V2_Datasheet.pdf
+package epd1in54
+
+import (
+	"image/color"
+	"machine"
+	"time"
+)
+
+type Config struct {
+	Width        int16
+	Height       int16
+	LogicalWidth int16
+	Rotation     Rotation
+}
+
+type Device struct {
+	bus  machine.SPI
+	cs   machine.Pin
+	dc   machine.Pin
+	rst  machine.Pin
+	busy machine.Pin
+
+	buffer   []uint8
+	rotation Rotation
+}
+
+type Rotation uint8
+
+var fullRefresh = [159]uint8{
+	0x80, 0x48, 0x40, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x40, 0x48, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x80, 0x48, 0x40, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x40, 0x48, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0xA, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x8, 0x1, 0x0, 0x8, 0x1, 0x0, 0x2,
+	0xA, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x0, 0x0, 0x0,
+	0x22, 0x17, 0x41, 0x0, 0x32, 0x20,
+}
+
+var partialRefresh = [159]uint8{
+	0x0, 0x40, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x80, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x40, 0x40, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0xF, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x1, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+	0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x0, 0x0, 0x0,
+	0x02, 0x17, 0x41, 0xB0, 0x32, 0x28,
+}
+
+// New returns a new epd1in54 driver. Pass in a fully configured SPI bus.
+func New(bus machine.SPI, csPin, dcPin, rstPin, busyPin machine.Pin) Device {
+	return Device{
+		buffer: make([]uint8, (uint32(Width)*uint32(Height))/8),
+		bus:    bus,
+		cs:     csPin,
+		dc:     dcPin,
+		rst:    rstPin,
+		busy:   busyPin,
+	}
+}
+
+func (d *Device) LDirInit(cfg Config) {
+	d.cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.rst.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.dc.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.busy.Configure(machine.PinConfig{Mode: machine.PinInput})
+
+	d.bus.Configure(machine.SPIConfig{
+		Frequency: 2000000,
+		Mode:      0,
+		LSBFirst:  false,
+	})
+
+	d.Reset()
+	d.WaitUntilIdle()
+
+	d.SendCommand(0x12)
+	d.WaitUntilIdle()
+
+	d.SendCommand(0x01)
+	d.SendData(0xC7)
+	d.SendData(0x00)
+	d.SendData(0x00)
+
+	d.SendCommand(0x11)
+	d.SendData(0x03)
+
+	d.SendCommand(0x44)
+	/* x point must be the multiple of 8 or the last 3 bits will be ignored */
+	d.SendData((0 >> 3) & 0xFF)
+	d.SendData((199 >> 3) & 0xFF)
+
+	d.SendCommand(0x45)
+	d.SendData(0 & 0xFF)
+	d.SendData((0 >> 8) & 0xFF)
+	d.SendData(199 & 0xFF)
+	d.SendData((199 >> 8) & 0xFF)
+
+	d.SendCommand(0x3C)
+	d.SendData(0x01)
+
+	d.SendCommand(0x18)
+	d.SendData(0x80)
+
+	d.SendCommand(0x22)
+	d.SendData(0xB1)
+
+	d.SendCommand(0x20)
+
+	d.SendCommand(0x4E)
+	d.SendData(0x00)
+
+	d.SendCommand(0x4F)
+	d.SendData(0xC7)
+	d.SendData(0x00)
+
+	d.WaitUntilIdle()
+	d.setLUT(fullRefresh)
+}
+
+func (d *Device) HDirInit(cfg Config) {
+	d.cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.rst.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.dc.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	d.busy.Configure(machine.PinConfig{Mode: machine.PinInput})
+
+	d.bus.Configure(machine.SPIConfig{
+		Frequency: 2000000,
+		Mode:      0,
+		LSBFirst:  false,
+	})
+
+	d.Reset()
+	d.WaitUntilIdle()
+
+	d.SendCommand(0x12)
+	d.WaitUntilIdle()
+
+	d.SendCommand(0x01)
+	d.SendData(0xC7)
+	d.SendData(0x00)
+	d.SendData(0x01)
+
+	d.SendCommand(0x11)
+	d.SendData(0x01)
+
+	d.SendCommand(0x44)
+	d.SendData(0x00)
+	d.SendData(0x18)
+
+	d.SendCommand(0x45)
+	d.SendData(0xC7)
+	d.SendData(0x00)
+	d.SendData(0x00)
+	d.SendData(0x00)
+
+	d.SendCommand(0x3C)
+	d.SendData(0x01)
+
+	d.SendCommand(0x18)
+	d.SendData(0x80)
+
+	d.SendCommand(0x22)
+	d.SendData(0xB1)
+
+	d.SendCommand(0x20)
+
+	d.SendCommand(0x4E)
+	d.SendData(0x00)
+
+	d.SendCommand(0x4F)
+	d.SendData(0xC7)
+	d.SendData(0x00)
+
+	d.WaitUntilIdle()
+	d.setLUT(fullRefresh)
+}
+
+func (d *Device) setLUT(lut [159]uint8) {
+	d.SendCommand(0x32)
+	for i := 0; i < 153; i++ {
+		d.SendData(lut[i])
+	}
+	d.WaitUntilIdle()
+
+	d.SendCommand(0x3F)
+	d.SendData(lut[153])
+
+	d.SendCommand(0x03)
+	d.SendData(lut[154])
+
+	d.SendCommand(0x04)
+	d.SendData(lut[155])
+	d.SendData(lut[156])
+	d.SendData(lut[157])
+
+	d.SendCommand(0x2C)
+	d.SendData(lut[158])
+}
+
+// Reset resets the display.
+func (d *Device) Reset() {
+	d.rst.High()
+	time.Sleep(20 * time.Millisecond)
+	d.rst.Low()
+	time.Sleep(5 * time.Millisecond)
+	d.rst.High()
+	time.Sleep(20 * time.Millisecond)
+}
+
+// SendCommand sends a command to the display
+func (d *Device) SendCommand(command uint8) {
+	d.sendDataCommand(true, command)
+}
+
+// SendData sends a data byte to the display
+func (d *Device) SendData(data uint8) {
+	d.sendDataCommand(false, data)
+}
+
+// sendDataCommand sends image data or a command to the screen
+func (d *Device) sendDataCommand(isCommand bool, data uint8) {
+	if isCommand {
+		d.dc.Low()
+	} else {
+		d.dc.High()
+	}
+	d.cs.Low()
+	d.bus.Transfer(data)
+	d.cs.High()
+}
+
+// SetPixel modifies the internal buffer in a single pixel.
+// The display have 2 colors: black and white
+// We use RGBA(0,0,0, 255) as white (transparent)
+// Anything else as black
+func (d *Device) SetPixel(x int16, y int16, c color.RGBA) {
+	x, y = d.xy(x, y)
+	if x < 0 || x >= Width || y < 0 || y >= Height {
+		return
+	}
+	byteIndex := (uint32(x) + uint32(y)*uint32(Width)) / 8
+	if c.R == 0 && c.G == 0 && c.B == 0 { // TRANSPARENT / WHITE
+		d.buffer[byteIndex] |= 0x80 >> uint8(x%8)
+	} else { // WHITE / EMPTY
+		d.buffer[byteIndex] &^= 0x80 >> uint8(x%8)
+	}
+}
+
+func (d *Device) DisplayImage(image []uint8) {
+	var w, h int
+	if Width%8 == 0 {
+		w = int(Width / 8)
+	} else {
+		w = int(Width/8 + 1)
+	}
+	h = int(Height)
+
+	d.SendCommand(0x24)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			d.SendData(image[i+j*w])
+		}
+	}
+
+	d.SendCommand(0x26)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			d.SendData(image[i+j*w])
+		}
+	}
+
+	d.displayFrame()
+}
+
+func (d *Device) Display() error {
+	var w, h int
+	if Width%8 == 0 {
+		w = int(Width / 8)
+	} else {
+		w = int(Width/8 + 1)
+	}
+	h = int(Height)
+
+	d.SendCommand(0x24)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			x := i + j*w
+			d.SendData(d.buffer[x])
+		}
+	}
+
+	d.SendCommand(0x26)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			x := i + j*w
+			d.SendData(d.buffer[x])
+		}
+	}
+
+	d.displayFrame()
+
+	return nil
+}
+
+func (d *Device) displayFrame() {
+	d.SendCommand(0x22)
+	d.SendData(0xC7)
+	d.SendCommand(0x20)
+	d.WaitUntilIdle()
+}
+
+func (d *Device) Clear() {
+	var w, h int
+	if Width%8 == 0 {
+		w = int(Width / 8)
+	} else {
+		w = int(Width/8 + 1)
+	}
+	h = int(Height)
+
+	d.SendCommand(0x24)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			d.SendData(0xff)
+		}
+	}
+
+	d.SendCommand(0x26)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			d.SendData(0xff)
+		}
+	}
+
+	d.displayFrame()
+}
+
+// WaitUntilIdle waits until the display is ready
+func (d *Device) WaitUntilIdle() {
+	for d.busy.Get() {
+		time.Sleep(100 * time.Millisecond)
+	}
+	time.Sleep(200 * time.Millisecond)
+}
+
+// IsBusy returns the busy status of the display
+func (d *Device) IsBusy() bool {
+	return d.busy.Get()
+}
+
+// ClearBuffer sets the buffer to 0xFF (white)
+func (d *Device) ClearBuffer() {
+	for i := 0; i < len(d.buffer); i++ {
+		d.buffer[i] = 0xFF
+	}
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	if d.rotation == ROTATION_90 || d.rotation == ROTATION_270 {
+		return Height, Width
+	}
+	return Width, Height
+}
+
+// SetRotation changes the rotation (clock-wise) of the device
+func (d *Device) SetRotation(rotation Rotation) {
+	d.rotation = rotation
+}
+
+// xy chages the coordinates according to the rotation
+func (d *Device) xy(x, y int16) (int16, int16) {
+	switch d.rotation {
+	case NO_ROTATION:
+		return x, y
+	case ROTATION_90:
+		return Width - y - 1, x
+	case ROTATION_180:
+		return Width - x - 1, Height - y - 1
+	case ROTATION_270:
+		return y, Height - x - 1
+	}
+	return x, y
+}
+
+func (d *Device) Sleep() {
+	d.SendCommand(0x10)
+	d.SendData(0x01)
+	time.Sleep(200 * time.Millisecond)
+
+	d.rst.Low()
+}

waveshare-epd/epd1in54/registers.go

@@ -0,0 +1,52 @@
+package epd1in54
+
+// Derived from https://github.com/waveshare/e-Paper/blob/master/Arduino/epd4in2/epd4in2.h
+
+const (
+	Width  = 200
+	Height = 200
+
+	PANEL_SETTING                  = 0x00
+	POWER_SETTING                  = 0x01
+	POWER_OFF                      = 0x02
+	POWER_OFF_SEQUENCE_SETTING     = 0x03
+	POWER_ON                       = 0x04
+	POWER_ON_MEASURE               = 0x05
+	BOOSTER_SOFT_START             = 0x06
+	DEEP_SLEEP                     = 0x07
+	DATA_START_TRANSMISSION_1      = 0x10
+	DATA_STOP                      = 0x11
+	DISPLAY_REFRESH                = 0x12
+	DATA_START_TRANSMISSION_2      = 0x13
+	LUT_FOR_VCOM                   = 0x20
+	LUT_WHITE_TO_WHITE             = 0x21
+	LUT_BLACK_TO_WHITE             = 0x22
+	LUT_WHITE_TO_BLACK             = 0x23
+	LUT_BLACK_TO_BLACK             = 0x24
+	PLL_CONTROL                    = 0x30
+	TEMPERATURE_SENSOR_COMMAND     = 0x40
+	TEMPERATURE_SENSOR_SELECTION   = 0x41
+	TEMPERATURE_SENSOR_WRITE       = 0x42
+	TEMPERATURE_SENSOR_READ        = 0x43
+	VCOM_AND_DATA_INTERVAL_SETTING = 0x50
+	LOW_POWER_DETECTION            = 0x51
+	TCON_SETTING                   = 0x60
+	RESOLUTION_SETTING             = 0x61
+	GSST_SETTING                   = 0x65
+	GET_STATUS                     = 0x71
+	AUTO_MEASUREMENT_VCOM          = 0x80
+	READ_VCOM_VALUE                = 0x81
+	VCM_DC_SETTING                 = 0x82
+	PARTIAL_WINDOW                 = 0x90
+	PARTIAL_IN                     = 0x91
+	PARTIAL_OUT                    = 0x92
+	PROGRAM_MODE                   = 0xA0
+	ACTIVE_PROGRAMMING             = 0xA1
+	READ_OTP                       = 0xA2
+	POWER_SAVING                   = 0xE3
+
+	NO_ROTATION  Rotation = 0
+	ROTATION_90  Rotation = 1
+	ROTATION_180 Rotation = 2
+	ROTATION_270 Rotation = 3
+)