Update for 0.6.0 release

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

CHANGELOG.md

@@ -1,3 +1,27 @@
+0.6.0
+---
+- **new devices**
+    - Support software SPI for APA102 (Itsy Bitsy M0 on-board "Dotstar" LED as example)
+
+0.5.0
+---
+- **new devices**
+    - LSM6DS3 accelerometer
+- **bugfixes**
+    - ws2812: fix timings for the nrf51
+- **enhancements**
+    - ws2812: Add build tag for Arduino Nano33 IoT
+
+0.4.0
+---
+- **new devices**
+    - SSD1331 TFT color display
+    - ST7735 TFT color display
+    - ST7789 TFT color display
+- **docs**
+    - espat
+        - complete list of dependencies for flashing NINA-W102 as used in Arduino Nano33 IoT board.
+
 0.3.0
 ---
 - **new devices**

Makefile

@@ -11,6 +11,7 @@ smoke-test:
 	@mkdir -p build
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/adxl345/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/apa102/main.go
+	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/apa102/itsybitsy-m0/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/at24cx/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/bh1750/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/blinkm/main.go
@@ -28,6 +29,7 @@ smoke-test:
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/hd44780/text/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/hub75/main.go
 	tinygo build -size short -o ./build/test.elf -target=circuitplay-express ./examples/lis3dh/main.go
+	tinygo build -size short -o ./build/test.elf -target=arduino-nano33 ./examples/lsm6ds3/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mag3110/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/microbitmatrix/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/mma8653/main.go
@@ -37,6 +39,9 @@ smoke-test:
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/sht3x/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/ssd1306/i2c_128x32/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/ssd1306/spi_128x64/main.go
+	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/ssd1331/main.go
+	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/st7735/main.go
+	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/st7789/main.go
 	tinygo build -size short -o ./build/test.elf -target=circuitplay-express ./examples/thermistor/main.go
 	tinygo build -size short -o ./build/test.elf -target=itsybitsy-m0 ./examples/vl53l1x/main.go
 	tinygo build -size short -o ./build/test.elf -target=microbit ./examples/waveshare-epd/epd2in13/main.go

README.md

@@ -69,6 +69,7 @@ func main() {
 | [GPS module](https://www.u-blox.com/en/product/neo-6-series) | I2C/UART |
 | [HUB75 RGB led matrix](https://cdn-learn.adafruit.com/downloads/pdf/32x16-32x32-rgb-led-matrix.pdf) | SPI |
 | [LIS3DH accelerometer](https://www.st.com/resource/en/datasheet/lis3dh.pdf) | I2C |
+| [LSM6DS3 accelerometer](https://www.st.com/resource/en/datasheet/lsm6ds3.pdf) | I2C |
 | [MAG3110 magnetometer](https://www.nxp.com/docs/en/data-sheet/MAG3110.pdf) | I2C |
 | [BBC micro:bit LED matrix](https://github.com/bbcmicrobit/hardware/blob/master/SCH_BBC-Microbit_V1.3B.pdf) | GPIO |
 | [Microphone - PDM](https://cdn-learn.adafruit.com/assets/assets/000/049/977/original/MP34DT01-M.pdf) | I2S/PDM |
@@ -77,6 +78,9 @@ func main() {
 | [PCD8544 display](http://eia.udg.edu/~forest/PCD8544_1.pdf) | SPI |
 | [SHT3x Digital Humidity Sensor](https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/0_Datasheets/Humidity/Sensirion_Humidity_Sensors_SHT3x_Datasheet_digital.pdf) | I2C |
 | [SSD1306 OLED display](https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf) | I2C / SPI |
+| [SSD1331 TFT color display](https://www.crystalfontz.com/controllers/SolomonSystech/SSD1331/381/) | SPI |
+| [ST7735 TFT color display](https://www.crystalfontz.com/controllers/Sitronix/ST7735R/319/) | SPI |
+| [ST7789 TFT color display](https://cdn-shop.adafruit.com/product-files/3787/3787_tft_QT154H2201__________20190228182902.pdf) | SPI |
 | [Thermistor](https://www.farnell.com/datasheets/33552.pdf) | ADC |
 | [VL53L1X time-of-flight distance sensor](https://www.st.com/resource/en/datasheet/vl53l1x.pdf) | I2C |
 | [Waveshare 2.13" e-paper display](https://www.waveshare.com/w/upload/e/e6/2.13inch_e-Paper_Datasheet.pdf) | SPI |

apa102/apa102.go

@@ -21,15 +21,28 @@ const (
 
 // Device wraps APA102 SPI LEDs.
 type Device struct {
-	bus   machine.SPI
+	bus   SPI
 	Order int
 }
 
+// The SPI interface specifies the minimum functionality that a bus
+// implementation needs to provide for use by the APA102 driver.  Hardware
+// SPI from the TinyGo "machine" package implements this already.
+type SPI interface {
+	Tx(w, r []byte) error
+}
+
 // New returns a new APA102 driver. Pass in a fully configured SPI bus.
-func New(b machine.SPI) Device {
+func New(b SPI) Device {
 	return Device{bus: b, Order: BGR}
 }
 
+// NewSoftwareSPI returns a new APA102 driver that will use a software based
+// implementation of the SPI protocol.
+func NewSoftwareSPI(sckPin, mosiPin machine.Pin, delay uint32) Device {
+	return New(&bbSPI{SCK: sckPin, MOSI: mosiPin, Delay: delay})
+}
+
 // WriteColors writes the given RGBA color slice out using the APA102 protocol.
 // The A value (Alpha channel) is used for brightness, set to 0xff (255) for maximum.
 func (d Device) WriteColors(cs []color.RGBA) (n int, err error) {

apa102/softspi.go

@@ -0,0 +1,68 @@
+package apa102
+
+import "machine"
+
+// bbSPI is a dumb bit-bang implementation of SPI protocol that is hardcoded
+// to mode 0 and ignores trying to receive data. Just enough for the APA102.
+// Note: making this unexported for now because it is probable not suitable
+// most purposes other than the APA102 package. It might be desirable to make
+// this more generic and include it in the TinyGo "machine" package instead.
+type bbSPI struct {
+	SCK   machine.Pin
+	MOSI  machine.Pin
+	Delay uint32
+}
+
+// Configure sets up the SCK and MOSI pins as outputs and sets them low
+func (s *bbSPI) Configure() {
+	s.SCK.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	s.MOSI.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	s.SCK.Low()
+	s.MOSI.Low()
+	if s.Delay == 0 {
+		s.Delay = 1
+	}
+}
+
+// Tx matches signature of machine.SPI.Tx() and is used to send multiple bytes.
+// The r slice is ignored and no error will ever be returned.
+func (s *bbSPI) Tx(w []byte, r []byte) error {
+	s.Configure()
+	for _, b := range w {
+		s.Transfer(b)
+	}
+	return nil
+}
+
+// delay represents a quarter of the clock cycle
+func (s *bbSPI) delay() {
+	for i := uint32(0); i < s.Delay; {
+		i++
+	}
+}
+
+// Transfer is used to send a single byte.
+func (s *bbSPI) Transfer(b byte) {
+	for i := uint8(0); i < 8; i++ {
+
+		// half clock cycle high to start
+		s.SCK.High()
+		s.delay()
+
+		// write the value to MOSI (MSB first)
+		if b&(1<<(7-i)) == 0 {
+			s.MOSI.Low()
+		} else {
+			s.MOSI.High()
+		}
+		s.delay()
+
+		// half clock cycle low
+		s.SCK.Low()
+		s.delay()
+
+		// for actual SPI would try to read the MISO value here
+		s.delay()
+
+	}
+}

espat/README.md

@@ -16,7 +16,9 @@ https://github.com/hybridgroup/esp32-at
 
 To flash this firmware on the Arduino Nano33 IoT you will need to follow the following procedure:
 
-- Using the normal Arduino software, load the `SerialNINAPassthrough` sketch on to the board.
+- Install _Arduino SAMD Boards_ from the Boards Manager.
+- Install _WiFiNANO_ from the Library Manager.
+- Using the normal Arduino software, load the `SerialNINAPassthrough` sketch on to the board (in File -> Examples -> WiFiNINA-> Tools).
 - Flash the NINA 102 firmware using the `make flash` command in the https://github.com/hybridgroup/esp32-at repo.
 
 You only need to do this one time, and then the correct ESP-AT firmware will be on the NINA chip, and you can just flash the Arduino Nano33 IoT board using TinyGo. We should be able to remove some of these step in a future release of this software.

examples/apa102/itsybitsy-m0/main.go

@@ -0,0 +1,84 @@
+// This example demostrates how to control the "Dotstar" (APA102) LED included
+// on the Adafruit Itsy Bitsy M0 board.  It implements a "rainbow effect" based
+// on the following example:
+// https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/master/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_rainbow.py
+package main
+
+import (
+	"image/color"
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/apa102"
+)
+
+var (
+	apa apa102.Device
+
+	led   = machine.PWM{machine.LED}
+	leds  = make([]color.RGBA, 1)
+	wheel = &Wheel{Brightness: 0x10}
+)
+
+func init() {
+
+	// APA102 on Itsy Bitsy is connected to pins that require a software-based
+	// SPI implementation.
+	apa = apa102.NewSoftwareSPI(machine.PA00, machine.PA01, 1)
+
+	// Configure the regular on-board LED for PWM fading
+	machine.InitPWM()
+	led.Configure()
+
+}
+
+func main() {
+
+	// We'll fade the on-board LED in a goroutine to show/ensure that the APA102
+	// works fine with the scheduler enabled.  Comment this out to test this code
+	// with the scheduler disabled.
+	go func() {
+		for i, brightening := uint8(0), false; ; i++ {
+			if i == 0 {
+				brightening = !brightening
+				continue
+			}
+			var brightness uint16 = uint16(i) << 8
+			if !brightening {
+				brightness = 0xFFFF - brightness
+			}
+			led.Set(brightness)
+			time.Sleep(5 * time.Millisecond)
+		}
+	}()
+
+	// Use the "wheel" function from Adafruit's example to cycle the APA102
+	for {
+		leds[0] = wheel.Next()
+		apa.WriteColors(leds)
+		time.Sleep(25 * time.Millisecond)
+	}
+
+}
+
+// Wheel is a port of Adafruit's Circuit Python example referenced above.
+type Wheel struct {
+	Brightness uint8
+	pos        uint8
+}
+
+// Next increments the internal state of the color and returns the new RGBA
+func (w *Wheel) Next() (c color.RGBA) {
+	pos := w.pos
+	if w.pos < 85 {
+		c = color.RGBA{R: 0xFF - pos*3, G: pos * 3, B: 0x0, A: w.Brightness}
+	} else if w.pos < 170 {
+		pos -= 85
+		c = color.RGBA{R: 0x0, G: 0xFF - pos*3, B: pos * 3, A: w.Brightness}
+	} else {
+		pos -= 170
+		c = color.RGBA{R: pos * 3, G: 0x0, B: 0xFF - pos*3, A: w.Brightness}
+	}
+	w.pos++
+	return
+}

examples/lsm6ds3/main.go

@@ -0,0 +1,30 @@
+// Connects to an LSM6DS3 I2C a 6 axis Inertial Measurement Unit (IMU)
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/lsm6ds3"
+)
+
+func main() {
+	machine.I2C0.Configure(machine.I2CConfig{})
+
+	accel := lsm6ds3.New(machine.I2C0)
+	accel.Configure(lsm6ds3.Configuration{})
+	if !accel.Connected() {
+		println("LSM6DS3 not connected")
+		return
+	}
+
+	for {
+		x, y, z := accel.ReadAcceleration()
+		println("Acceleration:", float32(x)/1000000, float32(y)/1000000, float32(z)/1000000)
+		x, y, z = accel.ReadRotation()
+		println("Gyroscope:", float32(x)/1000000, float32(y)/1000000, float32(z)/1000000)
+		x, _ = accel.ReadTemperature()
+		println("Degrees C", float32(x)/1000, "\n\n")
+		time.Sleep(time.Millisecond * 1000)
+	}
+}

examples/ssd1331/main.go

@@ -0,0 +1,33 @@
+package ssd1331
+
+import (
+	"machine"
+
+	"image/color"
+
+	"tinygo.org/x/drivers/ssd1331"
+)
+
+func main() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		Frequency: 8000000,
+	})
+	display := ssd1331.New(machine.SPI0, machine.P6, machine.P7, machine.P8)
+	display.Configure(ssd1331.Config{})
+	display.SetContrast(0x30, 0x20, 0x30)
+	width, height := display.Size()
+
+	white := color.RGBA{255, 255, 255, 255}
+	red := color.RGBA{255, 0, 0, 255}
+	blue := color.RGBA{0, 0, 255, 255}
+	green := color.RGBA{0, 255, 0, 255}
+	black := color.RGBA{0, 0, 0, 255}
+
+	display.FillScreen(black)
+
+	display.FillRectangle(0, 0, width/2, height/2, white)
+	display.FillRectangle(width/2, 0, width/2, height/2, red)
+	display.FillRectangle(0, height/2, width/2, height/2, green)
+	display.FillRectangle(width/2, height/2, width/2, height/2, blue)
+	display.FillRectangle(width/4, height/4, width/2, height/2, black)
+}

examples/st7735/main.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"machine"
+
+	"image/color"
+
+	"tinygo.org/x/drivers/st7735"
+)
+
+func main() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		Frequency: 8000000,
+	})
+	display := st7735.New(machine.SPI0, machine.P6, machine.P7, machine.P8, machine.P9)
+	display.Configure(st7735.Config{})
+
+	width, height := display.Size()
+
+	white := color.RGBA{255, 255, 255, 255}
+	red := color.RGBA{255, 0, 0, 255}
+	blue := color.RGBA{0, 0, 255, 255}
+	green := color.RGBA{0, 255, 0, 255}
+	black := color.RGBA{0, 0, 0, 255}
+
+	display.FillScreen(black)
+
+	display.FillRectangle(0, 0, width/2, height/2, white)
+	display.FillRectangle(width/2, 0, width/2, height/2, red)
+	display.FillRectangle(0, height/2, width/2, height/2, green)
+	display.FillRectangle(width/2, height/2, width/2, height/2, blue)
+	display.FillRectangle(width/4, height/4, width/2, height/2, black)
+}

examples/st7789/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"machine"
+
+	"image/color"
+
+	"tinygo.org/x/drivers/st7789"
+)
+
+func main() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		Frequency: 8000000,
+		Mode:      3,
+	})
+	display := st7789.New(machine.SPI0, machine.P6, machine.P7, machine.P8)
+	display.Configure(st7789.Config{Rotation: st7789.NO_ROTATION})
+
+	width, height := display.Size()
+
+	white := color.RGBA{255, 255, 255, 255}
+	red := color.RGBA{255, 0, 0, 255}
+	blue := color.RGBA{0, 0, 255, 255}
+	green := color.RGBA{0, 255, 0, 255}
+	black := color.RGBA{0, 0, 0, 255}
+
+	display.FillScreen(black)
+
+	display.FillRectangle(0, 0, width/2, height/2, white)
+	display.FillRectangle(width/2, 0, width/2, height/2, red)
+	display.FillRectangle(0, height/2, width/2, height/2, green)
+	display.FillRectangle(width/2, height/2, width/2, height/2, blue)
+	display.FillRectangle(width/4, height/4, width/2, height/2, black)
+}

hd44780/hd44780.go

@@ -1,4 +1,4 @@
-// Package lis3dh provides a driver for the HD44780 LCD controller.
+// Package hd44780 provides a driver for the HD44780 LCD controller.
 //
 // Datasheet: https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
 //

lsm6ds3/lsm6ds3.go

@@ -0,0 +1,183 @@
+// Package lsm6ds3 implements a driver for the LSM6DS3 a 6 axis Inertial
+// Measurement Unit (IMU)
+//
+// Datasheet: https://www.st.com/resource/en/datasheet/lsm6ds3.pdf
+//
+package lsm6ds3 // import "tinygo.org/x/drivers/lsm6ds3"
+
+import (
+	"machine"
+)
+
+type AccelRange uint8
+type AccelSampleRate uint8
+type AccelBandwidth uint8
+
+type GyroRange uint8
+type GyroSampleRate uint8
+
+// Device wraps an I2C connection to a LSM6DS3 device.
+type Device struct {
+	bus             machine.I2C
+	Address         uint16
+	accelRange      AccelRange
+	accelSampleRate AccelSampleRate
+	accelBandWidth  AccelBandwidth
+	gyroRange       GyroRange
+	gyroSampleRate  GyroSampleRate
+	dataBufferSix   []uint8
+	dataBufferTwo   []uint8
+}
+
+// Configuration for LSM6DS3 device.
+type Configuration struct {
+	AccelRange       AccelRange
+	AccelSampleRate  AccelSampleRate
+	AccelBandWidth   AccelBandwidth
+	GyroRange        GyroRange
+	GyroSampleRate   GyroSampleRate
+	IsPedometer      bool
+	ResetStepCounter bool
+}
+
+// New creates a new LSM6DS3 connection. The I2C bus must already be
+// configured.
+//
+// This function only creates the Device object, it does not touch the device.
+func New(bus machine.I2C) Device {
+	return Device{bus: bus, Address: Address}
+}
+
+// Configure sets up the device for communication.
+func (d *Device) Configure(cfg Configuration) {
+	if cfg.AccelRange != 0 {
+		d.accelRange = cfg.AccelRange
+	} else {
+		d.accelRange = ACCEL_2G
+	}
+
+	if cfg.AccelSampleRate != 0 {
+		d.accelSampleRate = cfg.AccelSampleRate
+	} else {
+		d.accelSampleRate = ACCEL_SR_104
+	}
+
+	if cfg.AccelBandWidth != 0 {
+		d.accelBandWidth = cfg.AccelBandWidth
+	} else {
+		d.accelBandWidth = ACCEL_BW_100
+	}
+
+	if cfg.GyroRange != 0 {
+		d.gyroRange = cfg.GyroRange
+	} else {
+		d.gyroRange = GYRO_2000DPS
+	}
+
+	if cfg.GyroSampleRate != 0 {
+		d.gyroSampleRate = cfg.GyroSampleRate
+	} else {
+		d.gyroSampleRate = GYRO_SR_104
+	}
+
+	d.dataBufferSix = make([]uint8, 6)
+	d.dataBufferTwo = make([]uint8, 2)
+
+	if cfg.IsPedometer { // CONFIGURE AS PEDOMETER
+		// Configure accelerometer: 2G + 26Hz
+		d.bus.WriteRegister(uint8(d.Address), CTRL1_XL, []byte{uint8(ACCEL_2G) | uint8(ACCEL_SR_26)})
+
+		// Configure Zen_G, Yen_G, Xen_G, reset steps
+		if cfg.ResetStepCounter {
+			d.bus.WriteRegister(uint8(d.Address), CTRL10_C, []byte{0x3E})
+		} else {
+			d.bus.WriteRegister(uint8(d.Address), CTRL10_C, []byte{0x3C})
+		}
+
+		// Enable pedometer
+		d.bus.WriteRegister(uint8(d.Address), TAP_CFG, []byte{0x40})
+	} else { // NORMAL USE
+		// Configure accelerometer
+		data := make([]uint8, 1)
+		data[0] = uint8(d.accelRange) | uint8(d.accelSampleRate) | uint8(d.accelBandWidth)
+		d.bus.WriteRegister(uint8(d.Address), CTRL1_XL, data)
+
+		// Set ODR bit
+		d.bus.ReadRegister(uint8(d.Address), CTRL4_C, data)
+		data[0] = data[0] &^ BW_SCAL_ODR_ENABLED
+		data[0] |= BW_SCAL_ODR_ENABLED
+		d.bus.WriteRegister(uint8(d.Address), CTRL4_C, data)
+
+		// Configure gyroscope
+		data[0] = uint8(d.gyroRange) | uint8(d.gyroSampleRate)
+		d.bus.WriteRegister(uint8(d.Address), CTRL2_G, data)
+	}
+}
+
+// Connected returns whether a LSM6DS3 has been found.
+// It does a "who am I" request and checks the response.
+func (d *Device) Connected() bool {
+	data := []byte{0}
+	d.bus.ReadRegister(uint8(d.Address), WHO_AM_I, data)
+	return data[0] == 0x69
+}
+
+// ReadAcceleration reads the current acceleration from the device and returns
+// it 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) ReadAcceleration() (x int32, y int32, z int32) {
+	d.bus.ReadRegister(uint8(d.Address), OUTX_L_XL, d.dataBufferSix)
+	// k comes from "Table 3. Mechanical characteristics" 3 of the datasheet * 1000
+	k := int32(61) // 2G
+	if d.accelRange == ACCEL_4G {
+		k = 122
+	} else if d.accelRange == ACCEL_8G {
+		k = 244
+	} else if d.accelRange == ACCEL_16G {
+		k = 488
+	}
+	x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * k
+	y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * k
+	z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * k
+	return
+}
+
+// ReadRotation reads the current rotation from the device and returns it in
+// µ°/s (micro-degrees/sec). This means that if you were to do a complete
+// 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 int32, y int32, z int32) {
+	d.bus.ReadRegister(uint8(d.Address), OUTX_L_G, d.dataBufferSix)
+	// k comes from "Table 3. Mechanical characteristics" 3 of the datasheet * 1000
+	k := int32(4375) // 125DPS
+	if d.gyroRange == GYRO_250DPS {
+		k = 8750
+	} else if d.gyroRange == GYRO_500DPS {
+		k = 17500
+	} else if d.gyroRange == GYRO_1000DPS {
+		k = 35000
+	} else if d.gyroRange == GYRO_2000DPS {
+		k = 70000
+	}
+	x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * k
+	y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * k
+	z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * k
+	return
+}
+
+// ReadTemperature returns the temperature in celsius milli degrees (ºC/1000)
+func (d *Device) ReadTemperature() (int32, error) {
+	d.bus.ReadRegister(uint8(d.Address), OUT_TEMP_L, d.dataBufferTwo)
+
+	// From "Table 5. Temperature sensor characteristics"
+	// temp = value/16 + 25
+	t := 25000 + (int32(int16((int16(d.dataBufferTwo[1])<<8)|int16(d.dataBufferTwo[0])))*125)/2
+	return t, nil
+}
+
+// ReadSteps returns the steps of the pedometer
+func (d *Device) ReadSteps() int32 {
+	d.bus.ReadRegister(uint8(d.Address), STEP_COUNTER_L, d.dataBufferTwo)
+	return int32(int16((uint16(d.dataBufferTwo[1]) << 8) | uint16(d.dataBufferTwo[0])))
+}

lsm6ds3/registers.go

@@ -0,0 +1,83 @@
+package lsm6ds3
+
+// Constants/addresses used for I2C.
+
+// The I2C address which this device listens to.
+const Address = 0x6A
+
+const (
+	WHO_AM_I             = 0x0F
+	STATUS               = 0x1E
+	CTRL1_XL             = 0x10
+	CTRL2_G              = 0x11
+	CTRL3_C              = 0x12
+	CTRL4_C              = 0x13
+	CTRL5_C              = 0x14
+	CTRL6_C              = 0x15
+	CTRL7_G              = 0x16
+	CTRL8_XL             = 0x17
+	CTRL9_XL             = 0x18
+	CTRL10_C             = 0x19
+	OUTX_L_G             = 0x22
+	OUTX_H_G             = 0x23
+	OUTY_L_G             = 0x24
+	OUTY_H_G             = 0x25
+	OUTZ_L_G             = 0x26
+	OUTZ_H_G             = 0x27
+	OUTX_L_XL            = 0x28
+	OUTX_H_XL            = 0x29
+	OUTY_L_XL            = 0x2A
+	OUTY_H_XL            = 0x2B
+	OUTZ_L_XL            = 0x2C
+	OUTZ_H_XL            = 0x2D
+	OUT_TEMP_L           = 0x20
+	OUT_TEMP_H           = 0x21
+	BW_SCAL_ODR_DISABLED = 0x00
+	BW_SCAL_ODR_ENABLED  = 0x80
+	STEP_TIMESTAMP_L     = 0x49
+	STEP_TIMESTAMP_H     = 0x4A
+	STEP_COUNTER_L       = 0x4B
+	STEP_COUNTER_H       = 0x4C
+	STEP_COUNT_DELTA     = 0x15
+	TAP_CFG              = 0x58
+	INT1_CTRL            = 0x0D
+
+	ACCEL_2G  AccelRange = 0x00
+	ACCEL_4G  AccelRange = 0x08
+	ACCEL_8G  AccelRange = 0x0C
+	ACCEL_16G AccelRange = 0x04
+
+	ACCEL_SR_OFF   AccelSampleRate = 0x00
+	ACCEL_SR_13    AccelSampleRate = 0x10
+	ACCEL_SR_26    AccelSampleRate = 0x20
+	ACCEL_SR_52    AccelSampleRate = 0x30
+	ACCEL_SR_104   AccelSampleRate = 0x40
+	ACCEL_SR_208   AccelSampleRate = 0x50
+	ACCEL_SR_416   AccelSampleRate = 0x60
+	ACCEL_SR_833   AccelSampleRate = 0x70
+	ACCEL_SR_1666  AccelSampleRate = 0x80
+	ACCEL_SR_3332  AccelSampleRate = 0x90
+	ACCEL_SR_6664  AccelSampleRate = 0xA0
+	ACCEL_SR_13330 AccelSampleRate = 0xB0
+
+	ACCEL_BW_50  AccelBandwidth = 0x03
+	ACCEL_BW_100 AccelBandwidth = 0x02
+	ACCEL_BW_200 AccelBandwidth = 0x01
+	ACCEL_BW_400 AccelBandwidth = 0x00
+
+	//GYRO_125DPS  GyroRange = 0x01
+	GYRO_250DPS  GyroRange = 0x00
+	GYRO_500DPS  GyroRange = 0x04
+	GYRO_1000DPS GyroRange = 0x08
+	GYRO_2000DPS GyroRange = 0x0C
+
+	GYRO_SR_OFF  GyroSampleRate = 0x00
+	GYRO_SR_13   GyroSampleRate = 0x10
+	GYRO_SR_26   GyroSampleRate = 0x20
+	GYRO_SR_52   GyroSampleRate = 0x30
+	GYRO_SR_104  GyroSampleRate = 0x40
+	GYRO_SR_208  GyroSampleRate = 0x50
+	GYRO_SR_416  GyroSampleRate = 0x60
+	GYRO_SR_833  GyroSampleRate = 0x70
+	GYRO_SR_1666 GyroSampleRate = 0x80
+)

ssd1331/registers.go

@@ -0,0 +1,33 @@
+package ssd1331
+
+// Registers
+const (
+	DRAWLINE       = 0x21
+	DRAWRECT       = 0x22
+	FILL           = 0x26
+	SETCOLUMN      = 0x15
+	SETROW         = 0x75
+	CONTRASTA      = 0x81
+	CONTRASTB      = 0x82
+	CONTRASTC      = 0x83
+	MASTERCURRENT  = 0x87
+	SETREMAP       = 0xA0
+	STARTLINE      = 0xA1
+	DISPLAYOFFSET  = 0xA2
+	NORMALDISPLAY  = 0xA4
+	DISPLAYALLON   = 0xA5
+	DISPLAYALLOFF  = 0xA6
+	INVERTDISPLAY  = 0xA7
+	SETMULTIPLEX   = 0xA8
+	SETMASTER      = 0xAD
+	DISPLAYOFF     = 0xAE
+	DISPLAYON      = 0xAF
+	POWERMODE      = 0xB0
+	PRECHARGE      = 0xB1
+	CLOCKDIV       = 0xB3
+	PRECHARGEA     = 0x8A
+	PRECHARGEB     = 0x8B
+	PRECHARGEC     = 0x8C
+	PRECHARGELEVEL = 0xBB
+	VCOMH          = 0xBE
+)

ssd1331/ssd1331.go

@@ -0,0 +1,286 @@
+// Package ssd1331 implements a driver for the SSD1331 TFT color displays.
+//
+// Datasheet: https://www.crystalfontz.com/controllers/SolomonSystech/SSD1331/381/
+//
+package ssd1331 // import "tinygo.org/x/drivers/ssd1331"
+
+import (
+	"image/color"
+	"machine"
+
+	"errors"
+	"time"
+)
+
+type Model uint8
+type Rotation uint8
+
+// Device wraps an SPI connection.
+type Device struct {
+	bus         machine.SPI
+	dcPin       machine.Pin
+	resetPin    machine.Pin
+	csPin       machine.Pin
+	width       int16
+	height      int16
+	batchLength int16
+	isBGR       bool
+	batchData   []uint8
+}
+
+// Config is the configuration for the display
+type Config struct {
+	Width  int16
+	Height int16
+}
+
+// New creates a new ST7735 connection. The SPI wire must already be configured.
+func New(bus machine.SPI, resetPin, dcPin, csPin machine.Pin) Device {
+	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	return Device{
+		bus:      bus,
+		dcPin:    dcPin,
+		resetPin: resetPin,
+		csPin:    csPin,
+	}
+}
+
+// Configure initializes the display with default configuration
+func (d *Device) Configure(cfg Config) {
+	if cfg.Width != 0 {
+		d.width = cfg.Width
+	} else {
+		d.width = 96
+	}
+	if cfg.Height != 0 {
+		d.height = cfg.Height
+	} else {
+		d.height = 64
+	}
+
+	d.batchLength = d.width
+	if d.height > d.width {
+		d.batchLength = d.height
+	}
+	d.batchLength += d.batchLength & 1
+	d.batchData = make([]uint8, d.batchLength*2)
+
+	// reset the device
+	d.resetPin.High()
+	time.Sleep(100 * time.Millisecond)
+	d.resetPin.Low()
+	time.Sleep(100 * time.Millisecond)
+	d.resetPin.High()
+	time.Sleep(200 * time.Millisecond)
+
+	// Initialization
+	d.Command(DISPLAYOFF)
+	d.Command(SETREMAP)
+	d.Command(0x72) // RGB
+	//d.Command(0x76) // BGR
+	d.Command(STARTLINE)
+	d.Command(0x0)
+	d.Command(DISPLAYOFFSET)
+	d.Command(0x0)
+	d.Command(NORMALDISPLAY)
+	d.Command(SETMULTIPLEX)
+	d.Command(0x3F)
+	d.Command(SETMASTER)
+	d.Command(0x8E)
+	d.Command(POWERMODE)
+	d.Command(0x0B)
+	d.Command(PRECHARGE)
+	d.Command(0x31)
+	d.Command(CLOCKDIV)
+	d.Command(0xF0)
+	d.Command(PRECHARGEA)
+	d.Command(0x64)
+	d.Command(PRECHARGEB)
+	d.Command(0x78)
+	d.Command(PRECHARGEC)
+	d.Command(0x64)
+	d.Command(PRECHARGELEVEL)
+	d.Command(0x3A)
+	d.Command(VCOMH)
+	d.Command(0x3E)
+	d.Command(MASTERCURRENT)
+	d.Command(0x06)
+	d.Command(CONTRASTA)
+	d.Command(0x91)
+	d.Command(CONTRASTB)
+	d.Command(0x50)
+	d.Command(CONTRASTC)
+	d.Command(0x7D)
+	d.Command(DISPLAYON)
+}
+
+// Display does nothing, there's no buffer as it might be too big for some boards
+func (d *Device) Display() error {
+	return nil
+}
+
+// SetPixel sets a pixel in the screen
+func (d *Device) SetPixel(x int16, y int16, c color.RGBA) {
+	if x < 0 || y < 0 || x >= d.width || y >= d.height {
+		return
+	}
+	d.FillRectangle(x, y, 1, 1, c)
+}
+
+// setWindow prepares the screen to be modified at a given rectangle
+func (d *Device) setWindow(x, y, w, h int16) {
+	/*d.Tx([]uint8{SETCOLUMN}, true)
+	d.Tx([]uint8{uint8(x), uint8(x + w - 1)}, false)
+	d.Tx([]uint8{SETROW}, true)
+	d.Tx([]uint8{uint8(y), uint8(y + h - 1)}, false)*/
+	d.Command(SETCOLUMN)
+	d.Command(uint8(x))
+	d.Command(uint8(x + w - 1))
+	d.Command(SETROW)
+	d.Command(uint8(y))
+	d.Command(uint8(y + h - 1))
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= d.width || (x+width) > d.width || y >= d.height || (y+height) > d.height {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	d.setWindow(x, y, width, height)
+	c565 := RGBATo565(c)
+	c1 := uint8(c565 >> 8)
+	c2 := uint8(c565)
+
+	var i int16
+	for i = 0; i < d.batchLength; i++ {
+		d.batchData[i*2] = c1
+		d.batchData[i*2+1] = c2
+	}
+	i = width * height
+	for i > 0 {
+		if i >= d.batchLength {
+			d.Tx(d.batchData, false)
+		} else {
+			d.Tx(d.batchData[:i*2], false)
+		}
+		i -= d.batchLength
+	}
+	return nil
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a buffer
+func (d *Device) FillRectangleWithBuffer(x, y, width, height int16, buffer []color.RGBA) error {
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= d.width || (x+width) > d.width || y >= d.height || (y+height) > d.height {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	k := width * height
+	l := int16(len(buffer))
+	if k != l {
+		return errors.New("buffer length does not match with rectangle size")
+	}
+
+	d.setWindow(x, y, width, height)
+
+	offset := int16(0)
+	for k > 0 {
+		for i := int16(0); i < d.batchLength; i++ {
+			if offset+i < l {
+				c565 := RGBATo565(buffer[offset+i])
+				c1 := uint8(c565 >> 8)
+				c2 := uint8(c565)
+				d.batchData[i*2] = c1
+				d.batchData[i*2+1] = c2
+			}
+		}
+		if k >= d.batchLength {
+			d.Tx(d.batchData, false)
+		} else {
+			d.Tx(d.batchData[:k*2], false)
+		}
+		k -= d.batchLength
+		offset += d.batchLength
+	}
+	return nil
+}
+
+// DrawFastVLine draws a vertical line faster than using SetPixel
+func (d *Device) DrawFastVLine(x, y0, y1 int16, c color.RGBA) {
+	if y0 > y1 {
+		y0, y1 = y1, y0
+	}
+	d.FillRectangle(x, y0, 1, y1-y0+1, c)
+}
+
+// DrawFastHLine draws a horizontal line faster than using SetPixel
+func (d *Device) DrawFastHLine(x0, x1, y int16, c color.RGBA) {
+	if x0 > x1 {
+		x0, x1 = x1, x0
+	}
+	d.FillRectangle(x0, y, x1-x0+1, y, c)
+}
+
+// FillScreen fills the screen with a given color
+func (d *Device) FillScreen(c color.RGBA) {
+	d.FillRectangle(0, 0, d.width, d.height, c)
+}
+
+// SetContrast sets the three contrast values (A, B & C)
+func (d *Device) SetContrast(contrastA, contrastB, contrastC uint8) {
+	d.Command(CONTRASTA)
+	d.Command(contrastA)
+	d.Command(CONTRASTB)
+	d.Command(contrastB)
+	d.Command(CONTRASTC)
+	d.Command(contrastC)
+}
+
+// Command sends a command to the display
+func (d *Device) Command(command uint8) {
+	d.Tx([]byte{command}, true)
+}
+
+// Command sends a data to the display
+func (d *Device) Data(data uint8) {
+	d.Tx([]byte{data}, false)
+}
+
+// Tx sends data to the display
+func (d *Device) Tx(data []byte, isCommand bool) {
+	if isCommand {
+		d.csPin.High()
+		d.dcPin.Low()
+		d.csPin.Low()
+
+		d.bus.Tx(data, nil)
+		d.csPin.High()
+	} else {
+		d.csPin.High()
+		d.dcPin.High()
+		d.csPin.Low()
+
+		d.bus.Tx(data, nil)
+		d.csPin.High()
+	}
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	return d.width, d.height
+}
+
+// IsBGR changes the color mode (RGB/BGR)
+func (d *Device) IsBGR(bgr bool) {
+	d.isBGR = bgr
+}
+
+// RGBATo565 converts a color.RGBA to uint16 used in the display
+func RGBATo565(c color.RGBA) uint16 {
+	r, g, b, _ := c.RGBA()
+	return uint16((r & 0xF800) +
+		((g & 0xFC00) >> 5) +
+		((b & 0xF800) >> 11))
+}

st7735/README.md

@@ -0,0 +1,9 @@
+# ST7735 driver
+
+There are multiple devices using the ST7735 chip, and there are multiple versions ST7735B, ST7735R & ST7735S. Two apparently identical displays might have different configurations. The most common issues are:
+
+* Colors are inverted (black is white and viceversa), invert the colors with display.InvertColors(true)
+* Colors are not right (red is blue and viceversa, but green is ok), some displays uses BRG instead of RGB for defining colors, change the mode with display.IsBGR(true)
+* There is noise/snow/confetti in the screen, probably rows and columns offsets are wrong, configure them with st7735.Config{RowOffset:XX, ColumnOffset:YY}
+
+If nothing of the above works, your device may need a different boot-up process.

st7735/registers.go

@@ -0,0 +1,57 @@
+package st7735
+
+// Registers
+const (
+	NOP        = 0x00
+	SWRESET    = 0x01
+	RDDID      = 0x04
+	RDDST      = 0x09
+	SLPIN      = 0x10
+	SLPOUT     = 0x11
+	PTLON      = 0x12
+	NORON      = 0x13
+	INVOFF     = 0x20
+	INVON      = 0x21
+	DISPOFF    = 0x28
+	DISPON     = 0x29
+	CASET      = 0x2A
+	RASET      = 0x2B
+	RAMWR      = 0x2C
+	RAMRD      = 0x2E
+	PTLAR      = 0x30
+	COLMOD     = 0x3A
+	MADCTL     = 0x36
+	MADCTL_MY  = 0x80
+	MADCTL_MX  = 0x40
+	MADCTL_MV  = 0x20
+	MADCTL_ML  = 0x10
+	MADCTL_RGB = 0x00
+	MADCTL_BGR = 0x08
+	MADCTL_MH  = 0x04
+	RDID1      = 0xDA
+	RDID2      = 0xDB
+	RDID3      = 0xDC
+	RDID4      = 0xDD
+	FRMCTR1    = 0xB1
+	FRMCTR2    = 0xB2
+	FRMCTR3    = 0xB3
+	INVCTR     = 0xB4
+	DISSET5    = 0xB6
+	PWCTR1     = 0xC0
+	PWCTR2     = 0xC1
+	PWCTR3     = 0xC2
+	PWCTR4     = 0xC3
+	PWCTR5     = 0xC4
+	VMCTR1     = 0xC5
+	PWCTR6     = 0xFC
+	GMCTRP1    = 0xE0
+	GMCTRN1    = 0xE1
+
+	GREENTAB   Model = 0
+	MINI80x160 Model = 1
+
+	NO_ROTATION  Rotation = 0
+	ROTATION_90  Rotation = 1 // 90 degrees clock-wise rotation
+	ROTATION_180 Rotation = 2
+	ROTATION_270 Rotation = 3
+)

st7735/st7735.go

@@ -0,0 +1,440 @@
+// Package st7735 implements a driver for the ST7735 TFT displays, it comes in various screen sizes.
+//
+// Datasheet: https://www.crystalfontz.com/controllers/Sitronix/ST7735R/319/
+//
+package st7735 // import "tinygo.org/x/drivers/st7735"
+
+import (
+	"image/color"
+	"machine"
+	"time"
+
+	"errors"
+)
+
+type Model uint8
+type Rotation uint8
+
+// Device wraps an SPI connection.
+type Device struct {
+	bus          machine.SPI
+	dcPin        machine.Pin
+	resetPin     machine.Pin
+	csPin        machine.Pin
+	blPin        machine.Pin
+	width        int16
+	height       int16
+	columnOffset int16
+	rowOffset    int16
+	rotation     Rotation
+	batchLength  int16
+	model        Model
+	isBGR        bool
+	batchData    []uint8
+}
+
+// Config is the configuration for the display
+type Config struct {
+	Width        int16
+	Height       int16
+	Rotation     Rotation
+	Model        Model
+	RowOffset    int16
+	ColumnOffset int16
+}
+
+// New creates a new ST7735 connection. The SPI wire must already be configured.
+func New(bus machine.SPI, resetPin, dcPin, csPin, blPin machine.Pin) Device {
+	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	csPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	blPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	return Device{
+		bus:      bus,
+		dcPin:    dcPin,
+		resetPin: resetPin,
+		csPin:    csPin,
+		blPin:    blPin,
+	}
+}
+
+// Configure initializes the display with default configuration
+func (d *Device) Configure(cfg Config) {
+	d.model = cfg.Model
+	if cfg.Width != 0 {
+		d.width = cfg.Width
+	} else {
+		if d.model == MINI80x160 {
+			d.width = 80
+		} else {
+			d.width = 128
+		}
+	}
+	if cfg.Height != 0 {
+		d.height = cfg.Height
+	} else {
+		d.height = 160
+	}
+	d.rotation = cfg.Rotation
+
+	if cfg.RowOffset != 0 {
+		d.rowOffset = cfg.RowOffset
+	} else {
+		d.rowOffset = 1
+	}
+	if cfg.ColumnOffset != 0 {
+		d.columnOffset = cfg.ColumnOffset
+	} else {
+		if d.model == MINI80x160 {
+			d.columnOffset = 26
+		} else {
+			d.columnOffset = 2
+		}
+	}
+
+	d.batchLength = d.width
+	if d.height > d.width {
+		d.batchLength = d.height
+	}
+	d.batchLength += d.batchLength & 1
+	d.batchData = make([]uint8, d.batchLength*2)
+
+	// reset the device
+	d.resetPin.High()
+	time.Sleep(5 * time.Millisecond)
+	d.resetPin.Low()
+	time.Sleep(20 * time.Millisecond)
+	d.resetPin.High()
+	time.Sleep(150 * time.Millisecond)
+
+	// Common initialization
+	d.Command(SWRESET)
+	time.Sleep(150 * time.Millisecond)
+	d.Command(SLPOUT)
+	time.Sleep(500 * time.Millisecond)
+	d.Command(FRMCTR1)
+	d.Data(0x01)
+	d.Data(0x2C)
+	d.Data(0x2D)
+	d.Command(FRMCTR2)
+	d.Data(0x01)
+	d.Data(0x2C)
+	d.Data(0x2D)
+	d.Command(FRMCTR3)
+	d.Data(0x01)
+	d.Data(0x2C)
+	d.Data(0x2D)
+	d.Data(0x01)
+	d.Data(0x2C)
+	d.Data(0x2D)
+	d.Command(INVCTR)
+	d.Data(0x07)
+	d.Command(PWCTR1)
+	d.Data(0xA2)
+	d.Data(0x02)
+	d.Data(0x84)
+	d.Command(PWCTR2)
+	d.Data(0xC5)
+	d.Command(PWCTR3)
+	d.Data(0x0A)
+	d.Data(0x00)
+	d.Command(PWCTR4)
+	d.Data(0x8A)
+	d.Data(0x2A)
+	d.Command(PWCTR5)
+	d.Data(0x8A)
+	d.Data(0xEE)
+	d.Command(VMCTR1)
+	d.Data(0x0E)
+	d.Command(COLMOD)
+	d.Data(0x05)
+
+	if d.model == GREENTAB {
+		d.InvertColors(false)
+		d.Command(CASET)
+		d.Data(0x00)
+		d.Data(0x02)
+		d.Data(0x00)
+		d.Data(0x7F + 0x02)
+		d.Command(RASET)
+		d.Data(0x00)
+		d.Data(0x01)
+		d.Data(0x00)
+		d.Data(0x9F + 0x01)
+	} else if d.model == MINI80x160 {
+		d.isBGR = true
+		d.InvertColors(true)
+		d.Command(CASET)
+		d.Data(0x00)
+		d.Data(0x00)
+		d.Data(0x00)
+		d.Data(0x7F)
+		d.Command(RASET)
+		d.Data(0x00)
+		d.Data(0x00)
+		d.Data(0x00)
+		d.Data(0x9F)
+	}
+
+	// common color adjustment
+	d.Command(GMCTRP1)
+	d.Data(0x02)
+	d.Data(0x1C)
+	d.Data(0x07)
+	d.Data(0x12)
+	d.Data(0x37)
+	d.Data(0x32)
+	d.Data(0x29)
+	d.Data(0x2D)
+	d.Data(0x29)
+	d.Data(0x25)
+	d.Data(0x2B)
+	d.Data(0x39)
+	d.Data(0x00)
+	d.Data(0x01)
+	d.Data(0x03)
+	d.Data(0x10)
+	d.Command(GMCTRN1)
+	d.Data(0x03)
+	d.Data(0x1D)
+	d.Data(0x07)
+	d.Data(0x06)
+	d.Data(0x2E)
+	d.Data(0x2C)
+	d.Data(0x29)
+	d.Data(0x2D)
+	d.Data(0x2E)
+	d.Data(0x2E)
+	d.Data(0x37)
+	d.Data(0x3F)
+	d.Data(0x00)
+	d.Data(0x00)
+	d.Data(0x02)
+	d.Data(0x10)
+
+	d.Command(NORON)
+	time.Sleep(10 * time.Millisecond)
+	d.Command(DISPON)
+	time.Sleep(500 * time.Millisecond)
+
+	if cfg.Model == MINI80x160 {
+		d.Command(MADCTL)
+		d.Data(0xC0)
+	}
+
+	d.SetRotation(d.rotation)
+
+	d.blPin.High()
+}
+
+// Display does nothing, there's no buffer as it might be too big for some boards
+func (d *Device) Display() error {
+	return nil
+}
+
+// SetPixel sets a pixel in the screen
+func (d *Device) SetPixel(x int16, y int16, c color.RGBA) {
+	w, h := d.Size()
+	if x < 0 || y < 0 || x >= w || y >= h {
+		return
+	}
+	d.FillRectangle(x, y, 1, 1, c)
+}
+
+// setWindow prepares the screen to be modified at a given rectangle
+func (d *Device) setWindow(x, y, w, h int16) {
+	if d.rotation == NO_ROTATION || d.rotation == ROTATION_180 {
+		x += d.columnOffset
+		y += d.rowOffset
+	} else {
+		x += d.rowOffset
+		y += d.columnOffset
+	}
+	d.Tx([]uint8{CASET}, true)
+	d.Tx([]uint8{uint8(x >> 8), uint8(x), uint8((x + w - 1) >> 8), uint8(x + w - 1)}, false)
+	d.Tx([]uint8{RASET}, true)
+	d.Tx([]uint8{uint8(y >> 8), uint8(y), uint8((y + h - 1) >> 8), uint8(y + h - 1)}, false)
+	d.Command(RAMWR)
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	k, i := d.Size()
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= k || (x+width) > k || y >= i || (y+height) > i {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	d.setWindow(x, y, width, height)
+	c565 := RGBATo565(c)
+	c1 := uint8(c565 >> 8)
+	c2 := uint8(c565)
+
+	for i = 0; i < d.batchLength; i++ {
+		d.batchData[i*2] = c1
+		d.batchData[i*2+1] = c2
+	}
+	i = width * height
+	for i > 0 {
+		if i >= d.batchLength {
+			d.Tx(d.batchData, false)
+		} else {
+			d.Tx(d.batchData[:i*2], false)
+		}
+		i -= d.batchLength
+	}
+	return nil
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a buffer
+func (d *Device) FillRectangleWithBuffer(x, y, width, height int16, buffer []color.RGBA) error {
+	k, l := d.Size()
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= k || (x+width) > k || y >= l || (y+height) > l {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	k = width * height
+	l = int16(len(buffer))
+	if k != l {
+		return errors.New("buffer length does not match with rectangle size")
+	}
+
+	d.setWindow(x, y, width, height)
+
+	offset := int16(0)
+	for k > 0 {
+		for i := int16(0); i < d.batchLength; i++ {
+			if offset+i < l {
+				c565 := RGBATo565(buffer[offset+i])
+				c1 := uint8(c565 >> 8)
+				c2 := uint8(c565)
+				d.batchData[i*2] = c1
+				d.batchData[i*2+1] = c2
+			}
+		}
+		if k >= d.batchLength {
+			d.Tx(d.batchData, false)
+		} else {
+			d.Tx(d.batchData[:k*2], false)
+		}
+		k -= d.batchLength
+		offset += d.batchLength
+	}
+	return nil
+}
+
+// DrawFastVLine draws a vertical line faster than using SetPixel
+func (d *Device) DrawFastVLine(x, y0, y1 int16, c color.RGBA) {
+	if y0 > y1 {
+		y0, y1 = y1, y0
+	}
+	d.FillRectangle(x, y0, 1, y1-y0+1, c)
+}
+
+// DrawFastHLine draws a horizontal line faster than using SetPixel
+func (d *Device) DrawFastHLine(x0, x1, y int16, c color.RGBA) {
+	if x0 > x1 {
+		x0, x1 = x1, x0
+	}
+	d.FillRectangle(x0, y, x1-x0+1, y, c)
+}
+
+// FillScreen fills the screen with a given color
+func (d *Device) FillScreen(c color.RGBA) {
+	if d.rotation == NO_ROTATION || d.rotation == ROTATION_180 {
+		d.FillRectangle(0, 0, d.width, d.height, c)
+	} else {
+		d.FillRectangle(0, 0, d.height, d.width, c)
+	}
+}
+
+// SetRotation changes the rotation of the device (clock-wise)
+func (d *Device) SetRotation(rotation Rotation) {
+	madctl := uint8(0)
+	switch rotation % 4 {
+	case 0:
+		madctl = MADCTL_MX | MADCTL_MY
+		break
+	case 1:
+		madctl = MADCTL_MY | MADCTL_MV
+		break
+	case 2:
+		break
+	case 3:
+		madctl = MADCTL_MX | MADCTL_MV
+		break
+	}
+	if d.isBGR {
+		madctl |= MADCTL_BGR
+	}
+	d.Command(MADCTL)
+	d.Data(madctl)
+
+}
+
+// Command sends a command to the display
+func (d *Device) Command(command uint8) {
+	d.Tx([]byte{command}, true)
+}
+
+// Command sends a data to the display
+func (d *Device) Data(data uint8) {
+	d.Tx([]byte{data}, false)
+}
+
+// Tx sends data to the display
+func (d *Device) Tx(data []byte, isCommand bool) {
+	if isCommand {
+		d.csPin.High()
+		d.dcPin.Low()
+		d.csPin.Low()
+
+		d.bus.Tx(data, nil)
+		d.csPin.High()
+	} else {
+		d.csPin.High()
+		d.dcPin.High()
+		d.csPin.Low()
+
+		d.bus.Tx(data, nil)
+		d.csPin.High()
+	}
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	if d.rotation == NO_ROTATION || d.rotation == ROTATION_180 {
+		return d.width, d.height
+	}
+	return d.height, d.width
+}
+
+// EnableBacklight enables or disables the backlight
+func (d *Device) EnableBacklight(enable bool) {
+	if enable {
+		d.blPin.High()
+	} else {
+		d.blPin.Low()
+	}
+}
+
+// InverColors inverts the colors of the screen
+func (d *Device) InvertColors(invert bool) {
+	if invert {
+		d.Command(INVON)
+	} else {
+		d.Command(INVOFF)
+	}
+}
+
+// IsBGR changes the color mode (RGB/BGR)
+func (d *Device) IsBGR(bgr bool) {
+	d.isBGR = bgr
+}
+
+// RGBATo565 converts a color.RGBA to uint16 used in the display
+func RGBATo565(c color.RGBA) uint16 {
+	r, g, b, _ := c.RGBA()
+	return uint16((r & 0xF800) +
+		((g & 0xFC00) >> 5) +
+		((b & 0xF800) >> 11))
+}

st7789/registers.go

@@ -0,0 +1,54 @@
+package st7789
+
+// Registers
+const (
+	NOP        = 0x00
+	SWRESET    = 0x01
+	RDDID      = 0x04
+	RDDST      = 0x09
+	SLPIN      = 0x10
+	SLPOUT     = 0x11
+	PTLON      = 0x12
+	NORON      = 0x13
+	INVOFF     = 0x20
+	INVON      = 0x21
+	DISPOFF    = 0x28
+	DISPON     = 0x29
+	CASET      = 0x2A
+	RASET      = 0x2B
+	RAMWR      = 0x2C
+	RAMRD      = 0x2E
+	PTLAR      = 0x30
+	COLMOD     = 0x3A
+	MADCTL     = 0x36
+	MADCTL_MY  = 0x80
+	MADCTL_MX  = 0x40
+	MADCTL_MV  = 0x20
+	MADCTL_ML  = 0x10
+	MADCTL_RGB = 0x00
+	MADCTL_BGR = 0x08
+	MADCTL_MH  = 0x04
+	RDID1      = 0xDA
+	RDID2      = 0xDB
+	RDID3      = 0xDC
+	RDID4      = 0xDD
+	FRMCTR1    = 0xB1
+	FRMCTR2    = 0xB2
+	FRMCTR3    = 0xB3
+	INVCTR     = 0xB4
+	DISSET5    = 0xB6
+	PWCTR1     = 0xC0
+	PWCTR2     = 0xC1
+	PWCTR3     = 0xC2
+	PWCTR4     = 0xC3
+	PWCTR5     = 0xC4
+	VMCTR1     = 0xC5
+	PWCTR6     = 0xFC
+	GMCTRP1    = 0xE0
+	GMCTRN1    = 0xE1
+
+	NO_ROTATION  Rotation = 0
+	ROTATION_90  Rotation = 1 // 90 degrees clock-wise rotation
+	ROTATION_180 Rotation = 2
+	ROTATION_270 Rotation = 3
+)

st7789/st7789.go

@@ -0,0 +1,330 @@
+// Package st7789 implements a driver for the ST7789 TFT displays, it comes in various screen sizes.
+//
+// Datasheet: https://cdn-shop.adafruit.com/product-files/3787/3787_tft_QT154H2201__________20190228182902.pdf
+//
+package st7789 // import "tinygo.org/x/drivers/st7789"
+
+import (
+	"image/color"
+	"machine"
+	"time"
+
+	"errors"
+)
+
+type Rotation uint8
+
+// Device wraps an SPI connection.
+type Device struct {
+	bus             machine.SPI
+	dcPin           machine.Pin
+	resetPin        machine.Pin
+	blPin           machine.Pin
+	width           int16
+	height          int16
+	columnOffsetCfg int16
+	rowOffsetCfg    int16
+	columnOffset    int16
+	rowOffset       int16
+	rotation        Rotation
+	batchLength     int32
+	isBGR           bool
+}
+
+// Config is the configuration for the display
+type Config struct {
+	Width        int16
+	Height       int16
+	Rotation     Rotation
+	RowOffset    int16
+	ColumnOffset int16
+}
+
+// New creates a new ST7789 connection. The SPI wire must already be configured.
+func New(bus machine.SPI, resetPin, dcPin, blPin machine.Pin) Device {
+	dcPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	resetPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	blPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	return Device{
+		bus:      bus,
+		dcPin:    dcPin,
+		resetPin: resetPin,
+		blPin:    blPin,
+	}
+}
+
+// Configure initializes the display with default configuration
+func (d *Device) Configure(cfg Config) {
+	if cfg.Width != 0 {
+		d.width = cfg.Width
+	} else {
+		d.width = 240
+	}
+	if cfg.Height != 0 {
+		d.height = cfg.Height
+	} else {
+		d.height = 240
+	}
+	d.rotation = cfg.Rotation
+
+	if cfg.RowOffset != 0 {
+		d.rowOffsetCfg = cfg.RowOffset
+	} else {
+		d.rowOffsetCfg = 80
+	}
+	if cfg.ColumnOffset != 0 {
+		d.columnOffsetCfg = cfg.ColumnOffset
+	}
+
+	d.batchLength = int32(d.width)
+	if d.height > d.width {
+		d.batchLength = int32(d.height)
+	}
+	d.batchLength += d.batchLength & 1
+
+	// reset the device
+	d.resetPin.High()
+	time.Sleep(5 * time.Millisecond)
+	d.resetPin.Low()
+	time.Sleep(20 * time.Millisecond)
+	d.resetPin.High()
+	time.Sleep(150 * time.Millisecond)
+
+	// Common initialization
+	d.Command(SWRESET)
+	time.Sleep(150 * time.Millisecond)
+	d.Command(SLPOUT)
+	time.Sleep(500 * time.Millisecond)
+	d.Command(COLMOD)
+	d.Data(0x55)
+	time.Sleep(10 * time.Millisecond)
+
+	d.SetRotation(d.rotation)
+
+	d.Command(CASET)
+	d.Data(0x00)
+	d.Data(uint8(d.columnOffset))
+	d.Data((240 + uint8(d.columnOffset)) >> 8)
+	d.Data(((240 + uint8(d.columnOffset)) >> 8) & 0xFF)
+	d.Command(RASET)
+	d.Data(0x00)
+	d.Data(uint8(d.rowOffset))
+	d.Data((240 + uint8(d.rowOffset)) >> 8)
+	d.Data(((240 + uint8(d.rowOffset)) >> 8) & 0xFF)
+
+	d.InvertColors(true)
+
+	d.Command(NORON)
+	time.Sleep(10 * time.Millisecond)
+	d.Command(DISPON)
+	time.Sleep(500 * time.Millisecond)
+
+	d.blPin.High()
+}
+
+// Display does nothing, there's no buffer as it might be too big for some boards
+func (d *Device) Display() error {
+	return nil
+}
+
+// SetPixel sets a pixel in the screen
+func (d *Device) SetPixel(x int16, y int16, c color.RGBA) {
+	if x < 0 || y < 0 ||
+		(((d.rotation == NO_ROTATION || d.rotation == ROTATION_180) && (x >= d.width || y >= d.height)) ||
+			((d.rotation == ROTATION_90 || d.rotation == ROTATION_270) && (x >= d.height || y >= d.width))) {
+		return
+	}
+	d.FillRectangle(x, y, 1, 1, c)
+}
+
+// setWindow prepares the screen to be modified at a given rectangle
+func (d *Device) setWindow(x, y, w, h int16) {
+	x += d.columnOffset
+	y += d.rowOffset
+	d.Tx([]uint8{CASET}, true)
+	d.Tx([]uint8{uint8(x << 8), uint8(x), uint8((x + w - 1) >> 8), uint8(x + w - 1)}, false)
+	d.Tx([]uint8{RASET}, true)
+	d.Tx([]uint8{uint8(y >> 8), uint8(y), uint8((y + h - 1) >> 8), uint8(y + h - 1)}, false)
+	d.Command(RAMWR)
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	k, i := d.Size()
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= k || (x+width) > k || y >= i || (y+height) > i {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	d.setWindow(x, y, width, height)
+	c565 := RGBATo565(c)
+	c1 := uint8(c565 >> 8)
+	c2 := uint8(c565)
+
+	data := make([]uint8, d.batchLength*2)
+	for i := int32(0); i < d.batchLength; i++ {
+		data[i*2] = c1
+		data[i*2+1] = c2
+	}
+	j := int32(width) * int32(height)
+	for j > 0 {
+		if j >= d.batchLength {
+			d.Tx(data, false)
+		} else {
+			d.Tx(data[:j*2], false)
+		}
+		j -= d.batchLength
+	}
+	return nil
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a buffer
+func (d *Device) FillRectangleWithBuffer(x, y, width, height int16, buffer []color.RGBA) error {
+	i, j := d.Size()
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= i || (x+width) > i || y >= j || (y+height) > j {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	if int32(width)*int32(height) != int32(len(buffer)) {
+		return errors.New("buffer length does not match with rectangle size")
+	}
+	d.setWindow(x, y, width, height)
+
+	k := int32(width) * int32(height)
+	data := make([]uint8, d.batchLength*2)
+	offset := int32(0)
+	for k > 0 {
+		for i := int32(0); i < d.batchLength; i++ {
+
+			c565 := RGBATo565(buffer[offset+i])
+			c1 := uint8(c565 >> 8)
+			c2 := uint8(c565)
+			data[i*2] = c1
+			data[i*2+1] = c2
+		}
+		if k >= d.batchLength {
+			d.Tx(data, false)
+		} else {
+			d.Tx(data[:k*2], false)
+		}
+		k -= d.batchLength
+		offset += d.batchLength
+	}
+	return nil
+}
+
+// DrawFastVLine draws a vertical line faster than using SetPixel
+func (d *Device) DrawFastVLine(x, y0, y1 int16, c color.RGBA) {
+	if y0 > y1 {
+		y0, y1 = y1, y0
+	}
+	d.FillRectangle(x, y0, 1, y1-y0+1, c)
+}
+
+// DrawFastHLine draws a horizontal line faster than using SetPixel
+func (d *Device) DrawFastHLine(x0, x1, y int16, c color.RGBA) {
+	if x0 > x1 {
+		x0, x1 = x1, x0
+	}
+	d.FillRectangle(x0, y, x1-x0+1, y, c)
+}
+
+// FillScreen fills the screen with a given color
+func (d *Device) FillScreen(c color.RGBA) {
+	if d.rotation == NO_ROTATION || d.rotation == ROTATION_180 {
+		d.FillRectangle(0, 0, d.width, d.height, c)
+	} else {
+		d.FillRectangle(0, 0, d.height, d.width, c)
+	}
+}
+
+// SetRotation changes the rotation of the device (clock-wise)
+func (d *Device) SetRotation(rotation Rotation) {
+	madctl := uint8(0)
+	switch rotation % 4 {
+	case 0:
+		madctl = MADCTL_MX | MADCTL_MY
+		d.rowOffset = d.rowOffsetCfg
+		d.columnOffset = d.columnOffsetCfg
+		break
+	case 1:
+		madctl = MADCTL_MY | MADCTL_MV
+		d.rowOffset = d.columnOffsetCfg
+		d.columnOffset = d.rowOffsetCfg
+		break
+	case 2:
+		d.rowOffset = 0
+		d.columnOffset = 0
+		break
+	case 3:
+		madctl = MADCTL_MX | MADCTL_MV
+		d.rowOffset = 0
+		d.columnOffset = 0
+		break
+	}
+	if d.isBGR {
+		madctl |= MADCTL_BGR
+	}
+	d.Command(MADCTL)
+	d.Data(madctl)
+
+}
+
+// Command sends a command to the display
+func (d *Device) Command(command uint8) {
+	d.Tx([]byte{command}, true)
+}
+
+// Command sends a data to the display
+func (d *Device) Data(data uint8) {
+	d.Tx([]byte{data}, false)
+}
+
+// Tx sends data to the display
+func (d *Device) Tx(data []byte, isCommand bool) {
+	if isCommand {
+		d.dcPin.Low()
+		d.bus.Tx(data, nil)
+	} else {
+		d.dcPin.High()
+		d.bus.Tx(data, nil)
+	}
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	if d.rotation == NO_ROTATION || d.rotation == ROTATION_180 {
+		return d.width, d.height
+	}
+	return d.height, d.width
+}
+
+// EnableBacklight enables or disables the backlight
+func (d *Device) EnableBacklight(enable bool) {
+	if enable {
+		d.blPin.High()
+	} else {
+		d.blPin.Low()
+	}
+}
+
+// InverColors inverts the colors of the screen
+func (d *Device) InvertColors(invert bool) {
+	if invert {
+		d.Command(INVON)
+	} else {
+		d.Command(INVOFF)
+	}
+}
+
+// IsBGR changes the color mode (RGB/BGR)
+func (d *Device) IsBGR(bgr bool) {
+	d.isBGR = bgr
+}
+
+// RGBATo565 converts a color.RGBA to uint16 used in the display
+func RGBATo565(c color.RGBA) uint16 {
+	r, g, b, _ := c.RGBA()
+	return uint16((r & 0xF800) +
+		((g & 0xFC00) >> 5) +
+		((b & 0xF800) >> 11))
+}

ws2812/ws2812_m0_16m.go

@@ -17,14 +17,16 @@ func (d Device) WriteByte(c byte) error {
 
 	// See:
 	// https://wp.josh.com/2014/05/13/ws2812-neopixels-are-not-so-finicky-once-you-get-to-know-them/
-	// T0H: 4  cycles or 250ns
-	// T0L: 14 cycles or 875ns -> together 18 cycles or 1125ns
-	// T1H: 10 cycles or 625ns
-	// T1H: 8  cycles or 500ns -> together 18 cycles or 1125ns
+	// Note: timings have been increased slightly to also support ws2811 LEDs.
+	// T0H: 5  cycles or 312.5ns
+	// T0L: 14 cycles or 875.0ns -> together 19 cycles or 1187.5ns
+	// T1H: 11 cycles or 687.5ns
+	// T1H: 8  cycles or 500.0ns -> together 19 cycles or 1187.5ns
 	value := uint32(c) << 24
 	arm.AsmFull(`
 	send_bit:
 		str   {maskSet}, {portSet}     @ [2]   T0H and T0L start here
+		nop                            @ [1]
 		lsls  {value}, #1              @ [1]
 		bcs.n skip_store               @ [1/3]
 		str   {maskClear}, {portClear} @ [2]   T0H -> T0L transition

ws2812/ws2812_m0_48m.go

@@ -1,4 +1,4 @@
-// +build circuitplay_express itsybitsy_m0
+// +build circuitplay_express itsybitsy_m0 arduino_nano33
 
 package ws2812