release: update changelog for 0.5.0

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

CHANGELOG.md

@@ -1,3 +1,12 @@
+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**

Makefile

@@ -28,6 +28,7 @@ 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

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 |

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)
+	}
+}

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
+)

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