AMG88xx thermal camera module

Makefile

@@ -13,6 +13,8 @@ smoke-test:
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/adxl345/main.go
 	@md5sum ./build/test.hex
+	tinygo build -size short -o ./build/test.hex -target=pybadge ./examples/amg88xx
+	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/apa102/main.go
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=itsybitsy-m0 ./examples/apa102/itsybitsy-m0/main.go

README.md

@@ -58,6 +58,7 @@ The following 45 devices are supported.
 |----------|-------------|
 | [ADT7410 I2C Temperature Sensor](https://www.analog.com/media/en/technical-documentation/data-sheets/ADT7410.pdf) | I2C |
 | [ADXL345 accelerometer](http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf) | I2C |
+| [AMG88xx 8x8 Thermal camera sensor](https://cdn-learn.adafruit.com/assets/assets/000/043/261/original/Grid-EYE_SPECIFICATIONS%28Reference%29.pdf) | I2C |
 | [APA102 RGB LED](https://cdn-shop.adafruit.com/product-files/2343/APA102C.pdf) | SPI |
 | [AT24CX 2-wire serial EEPROM](https://www.openimpulse.com/blog/wp-content/uploads/wpsc/downloadables/24C32-Datasheet.pdf) | I2C |
 | [BH1750 ambient light sensor](https://www.mouser.com/ds/2/348/bh1750fvi-e-186247.pdf) | I2C |

amg88xx/amg88xx.go

@@ -0,0 +1,158 @@
+// Package amg88xx provides a driver for the AMG88XX Thermal Camera
+//
+// Datasheet:
+// https://cdn-learn.adafruit.com/assets/assets/000/043/261/original/Grid-EYE_SPECIFICATIONS%28Reference%29.pdf
+package amg88xx // import "tinygo.org/x/drivers/amg88xx"
+
+import (
+	"machine"
+	"time"
+)
+
+// Device wraps an I2C connection to a AMG88xx device.
+type Device struct {
+	bus             machine.I2C
+	Address         uint16
+	data            []uint8
+	interruptMode   InterruptMode
+	interruptEnable uint8
+}
+
+type InterruptMode uint8
+
+type Config struct {
+}
+
+// New creates a new AMG88xx 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: AddressHigh,
+	}
+}
+
+// Configure sets up the device for communication
+func (d *Device) Configure(cfg Config) {
+	d.data = make([]uint8, 128)
+
+	d.SetPCTL(NORMAL_MODE)
+	d.SetReset(INITIAL_RESET)
+	d.SetFrameRate(FPS_10)
+
+	time.Sleep(100 * time.Millisecond)
+}
+
+// ReadPixels returns the 64 values (8x8 grid) of the sensor converted to  millicelsius
+func (d *Device) ReadPixels(buffer *[64]int16) {
+	d.bus.ReadRegister(uint8(d.Address), PIXEL_OFFSET, d.data)
+	for i := 0; i < 64; i++ {
+		buffer[i] = int16((uint16(d.data[2*i+1]) << 8) | uint16(d.data[2*i]))
+		if (buffer[i] & (1 << 11)) > 0 { // temperature negative
+			buffer[i] &= ^(1 << 11)
+			buffer[i] = -buffer[i]
+		}
+		buffer[i] *= PIXEL_TEMP_CONVERSION
+	}
+}
+
+// SetPCTL sets the PCTL
+func (d *Device) SetPCTL(pctl uint8) {
+	d.bus.WriteRegister(uint8(d.Address), PCTL, []byte{pctl})
+}
+
+// SetReset sets the reset value
+func (d *Device) SetReset(rst uint8) {
+	d.bus.WriteRegister(uint8(d.Address), RST, []byte{rst})
+}
+
+// SetFrameRate configures the frame rate
+func (d *Device) SetFrameRate(framerate uint8) {
+	d.bus.WriteRegister(uint8(d.Address), FPSC, []byte{framerate & 0x01})
+}
+
+// SetMovingAverageMode sets the moving average mode
+func (d *Device) SetMovingAverageMode(mode bool) {
+	var value uint8
+	if mode {
+		value = 1
+	}
+	d.bus.WriteRegister(uint8(d.Address), AVE, []byte{value << 5})
+}
+
+// SetInterruptLevels sets the interrupt levels
+func (d *Device) SetInterruptLevels(high int16, low int16) {
+	d.SetInterruptLevelsHysteresis(high, low, (high*95)/100)
+}
+
+// SetInterruptLevelsHysteresis sets the interrupt levels with hysteresis
+func (d *Device) SetInterruptLevelsHysteresis(high int16, low int16, hysteresis int16) {
+	high = high / PIXEL_TEMP_CONVERSION
+	if high < -4095 {
+		high = -4095
+	}
+	if high > 4095 {
+		high = 4095
+	}
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8(high & 0xFF)})
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8((high & 0xFF) >> 4)})
+
+	low = low / PIXEL_TEMP_CONVERSION
+	if low < -4095 {
+		low = -4095
+	}
+	if low > 4095 {
+		low = 4095
+	}
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8(low & 0xFF)})
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8((low & 0xFF) >> 4)})
+
+	hysteresis = hysteresis / PIXEL_TEMP_CONVERSION
+	if hysteresis < -4095 {
+		hysteresis = -4095
+	}
+	if hysteresis > 4095 {
+		hysteresis = 4095
+	}
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8(hysteresis & 0xFF)})
+	d.bus.WriteRegister(uint8(d.Address), INTHL, []byte{uint8((hysteresis & 0xFF) >> 4)})
+}
+
+// EnableInterrupt enables the interrupt pin on the device
+func (d *Device) EnableInterrupt() {
+	d.interruptEnable = 1
+	d.bus.WriteRegister(uint8(d.Address), INTC, []byte{((uint8(d.interruptMode) << 1) | d.interruptEnable) & 0x03})
+}
+
+// DisableInterrupt disables the interrupt pin on the device
+func (d *Device) DisableInterrupt() {
+	d.interruptEnable = 0
+	d.bus.WriteRegister(uint8(d.Address), INTC, []byte{((uint8(d.interruptMode) << 1) | d.interruptEnable) & 0x03})
+}
+
+// SetInterruptMode sets the interrupt mode
+func (d *Device) SetInterruptMode(mode InterruptMode) {
+	d.interruptMode = mode
+	d.bus.WriteRegister(uint8(d.Address), INTC, []byte{((uint8(d.interruptMode) << 1) | d.interruptEnable) & 0x03})
+}
+
+// GetInterrupt reads the state of the triggered interrupts
+func (d *Device) GetInterrupt() []uint8 {
+	data := make([]uint8, 8)
+	d.bus.ReadRegister(uint8(d.Address), INT_OFFSET, data)
+	return data
+}
+
+// ClearInterrupt clears any triggered interrupts
+func (d *Device) ClearInterrupt() {
+	d.SetReset(FLAG_RESET)
+}
+
+// ReadThermistor reads the onboard thermistor
+func (d *Device) ReadThermistor() int16 {
+	data := make([]uint8, 2)
+	d.bus.ReadRegister(uint8(d.Address), TTHL, data)
+	return (int16((uint16(data[1])<<8)|uint16(data[0])) * THERMISTOR_CONVERSION) / 10
+}

amg88xx/registers.go

@@ -0,0 +1,46 @@
+package amg88xx
+
+// The I2C address which this device listens to.
+const AddressHigh = 0x69
+const AddressLow = 0x68
+
+const (
+	PCTL         = 0x00
+	RST          = 0x01
+	FPSC         = 0x02
+	INTC         = 0x03
+	STAT         = 0x04
+	SCLR         = 0x05
+	AVE          = 0x07
+	INTHL        = 0x08
+	INTHH        = 0x09
+	INTLL        = 0x0A
+	INTLH        = 0x0B
+	IHYSL        = 0x0C
+	IHYSH        = 0x0D
+	TTHL         = 0x0E
+	TTHH         = 0x0F
+	INT_OFFSET   = 0x010
+	PIXEL_OFFSET = 0x80
+
+	// power modes
+	NORMAL_MODE = 0x00
+	SLEEP_MODE  = 0x01
+	STAND_BY_60 = 0x20
+	STAND_BY_10 = 0x21
+
+	// resets
+	FLAG_RESET    = 0x30
+	INITIAL_RESET = 0x3F
+
+	// frame rates
+	FPS_10 = 0x00
+	FPS_1  = 0x01
+
+	// interrupt modes
+	DIFFERENCE     InterruptMode = 0x00
+	ABSOLUTE_VALUE InterruptMode = 0x01
+
+	PIXEL_TEMP_CONVERSION = 250
+	THERMISTOR_CONVERSION = 625
+)

examples/amg88xx/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"image/color"
+	"machine"
+
+	"tinygo.org/x/drivers/st7735"
+
+	"tinygo.org/x/drivers/amg88xx"
+)
+
+func main() {
+
+	machine.SPI1.Configure(machine.SPIConfig{
+		SCK:       machine.SPI1_SCK_PIN,
+		MOSI:      machine.SPI1_MOSI_PIN,
+		MISO:      machine.SPI1_MISO_PIN,
+		Frequency: 8000000,
+	})
+	machine.I2C0.Configure(machine.I2CConfig{SCL: machine.SCL_PIN, SDA: machine.SDA_PIN})
+
+	display := st7735.New(machine.SPI1, machine.TFT_RST, machine.TFT_DC, machine.TFT_CS, machine.TFT_LITE)
+	display.Configure(st7735.Config{
+		Rotation: st7735.ROTATION_90,
+	})
+	display.FillScreen(color.RGBA{0, 0, 0, 255})
+
+	camera := amg88xx.New(machine.I2C0)
+	camera.Configure(amg88xx.Config{})
+
+	var data [64]int16
+	var value int16
+	for {
+		// get the values of the sensor in millicelsius
+		camera.ReadPixels(&data)
+
+		for j := int16(0); j < 8; j++ {
+			for i := int16(0); i < 8; i++ {
+				value = data[63-(i+j*8)]
+				// treat anything below 18°C as 18°C
+				if value < 18000 {
+					value = 0
+				} else {
+					value = (value - 18000) / 36
+					// our color array only have 433 values, avoid getting a value that doesn't exist
+					if value > 432 {
+						value = 432
+					}
+				}
+				// show the image on the PyBadge's display
+				display.FillRectangle(16+i*16, j*16, 16, 16, colors[value])
+			}
+		}
+	}
+
+}