mirror of
https://github.com/tinygo-org/drivers.git
synced 2026-08-10 18:03:41 +00:00
Ayke van Laethem
6763521eff
This type should be used whenever a sensor (or actuator?) works with a
temperature. For example, this commit changes the signature:
ReadTemperature() (int32, error)
to the following:
ReadTemperature() (drivers.Temperature, error)
I believe this is much clearer in intent. It also makes it trivial to
introduce common conversions. For example, there are already Celsius()
and Fahrenheit() methods to convert to the given units, as a floating
point. More units could be added as needed, for example a CelsiusInt().
121 lines
4.0 KiB
Go
121 lines
4.0 KiB
Go
// Package lsm6dsox implements a driver for the LSM6DSOX
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// a 6 axis Inertial Measurement Unit (IMU)
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//
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// Datasheet: https://www.st.com/resource/en/datasheet/lsm6dsox.pdf
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//
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package lsm6dsox // import "tinygo.org/x/drivers/lsm6dsox"
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import "tinygo.org/x/drivers"
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type AccelRange uint8
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type AccelSampleRate uint8
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type GyroRange uint8
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type GyroSampleRate uint8
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// Device wraps an I2C connection to a LSM6DSOX device.
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type Device struct {
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bus drivers.I2C
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Address uint16
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dataBufferSix []uint8
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dataBufferTwo []uint8
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accelMultiplier int32
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gyroMultiplier int32
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}
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// Configuration for LSM6DSOX device.
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type Configuration struct {
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AccelRange AccelRange
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AccelSampleRate AccelSampleRate
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GyroRange GyroRange
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GyroSampleRate GyroSampleRate
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}
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// New creates a new LSM6DSOX connection. The I2C bus must already be configured.
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//
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// This function only creates the Device object, it does not touch the device.
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func New(bus drivers.I2C) *Device {
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return &Device{
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bus: bus,
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Address: Address,
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dataBufferSix: make([]uint8, 6),
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dataBufferTwo: make([]uint8, 2),
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}
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}
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// Configure sets up the device for communication.
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func (d *Device) Configure(cfg Configuration) {
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// Multipliers come from "Table 2. Mechanical characteristics" of the datasheet * 1000
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switch cfg.AccelRange {
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case ACCEL_2G:
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d.accelMultiplier = 61
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case ACCEL_4G:
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d.accelMultiplier = 122
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case ACCEL_8G:
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d.accelMultiplier = 244
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case ACCEL_16G:
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d.accelMultiplier = 488
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}
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switch cfg.GyroRange {
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case GYRO_250DPS:
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d.gyroMultiplier = 8750
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case GYRO_500DPS:
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d.gyroMultiplier = 17500
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case GYRO_1000DPS:
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d.gyroMultiplier = 35000
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case GYRO_2000DPS:
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d.gyroMultiplier = 70000
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}
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data := make([]uint8, 1)
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// Configure accelerometer
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data[0] = uint8(cfg.AccelRange) | uint8(cfg.AccelSampleRate)
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d.bus.WriteRegister(uint8(d.Address), CTRL1_XL, data)
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// Configure gyroscope
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data[0] = uint8(cfg.GyroRange) | uint8(cfg.GyroSampleRate)
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d.bus.WriteRegister(uint8(d.Address), CTRL2_G, data)
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}
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// Connected returns whether a LSM6DSOX has been found.
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// It does a "who am I" request and checks the response.
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func (d *Device) Connected() bool {
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data := []byte{0}
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d.bus.ReadRegister(uint8(d.Address), WHO_AM_I, data)
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return data[0] == 0x6C
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}
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// ReadAcceleration reads the current acceleration from the device and returns
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// it in µg (micro-gravity). When one of the axes is pointing straight to Earth
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// and the sensor is not moving the returned value will be around 1000000 or
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// -1000000.
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func (d *Device) ReadAcceleration() (x int32, y int32, z int32) {
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d.bus.ReadRegister(uint8(d.Address), OUTX_L_A, d.dataBufferSix)
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x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * d.accelMultiplier
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y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * d.accelMultiplier
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z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * d.accelMultiplier
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return
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}
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// ReadRotation reads the current rotation from the device and returns it in
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// µ°/s (micro-degrees/sec). This means that if you were to do a complete
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// rotation along one axis and while doing so integrate all values over time,
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// you would get a value close to 360000000.
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func (d *Device) ReadRotation() (x int32, y int32, z int32) {
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d.bus.ReadRegister(uint8(d.Address), OUTX_L_G, d.dataBufferSix)
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x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * d.gyroMultiplier
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y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * d.gyroMultiplier
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z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * d.gyroMultiplier
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return
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}
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// ReadTemperature returns the temperature in celsius milli degrees (°C/1000)
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func (d *Device) ReadTemperature() (drivers.Temperature, error) {
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d.bus.ReadRegister(uint8(d.Address), OUT_TEMP_L, d.dataBufferTwo)
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// From "Table 4. Temperature sensor characteristics"
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// temp = value/256 + 25
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t := 25000 + (int32(int16((int16(d.dataBufferTwo[1])<<8)|int16(d.dataBufferTwo[0])))*125)/32
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return drivers.Temperature(t), nil
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}
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