lsm6dox: minimal correct implementation

This commit is contained in:
Yurii Soldak
2021-08-30 20:10:46 +02:00
committed by Ron Evans
parent b3af3f594e
commit ad6be40966
3 changed files with 299 additions and 0 deletions
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// Package lsm6dsox implements a driver for the LSM6DSOX
// a 6 axis Inertial Measurement Unit (IMU)
//
// Datasheet: https://www.st.com/resource/en/datasheet/lsm6dsox.pdf
//
package lsm6dsox // import "tinygo.org/x/drivers/lsm6dsox"
import "tinygo.org/x/drivers"
type AccelRange uint8
type AccelSampleRate uint8
type GyroRange uint8
type GyroSampleRate uint8
// Device wraps an I2C connection to a LSM6DSOX device.
type Device struct {
bus drivers.I2C
Address uint16
dataBufferSix []uint8
dataBufferTwo []uint8
accelMultiplier int32
gyroMultiplier int32
}
// Configuration for LSM6DSOX device.
type Configuration struct {
AccelRange AccelRange
AccelSampleRate AccelSampleRate
GyroRange GyroRange
GyroSampleRate GyroSampleRate
}
// New creates a new LSM6DSOX connection. The I2C bus must already be configured.
//
// This function only creates the Device object, it does not touch the device.
func New(bus drivers.I2C) *Device {
return &Device{
bus: bus,
Address: Address,
dataBufferSix: make([]uint8, 6),
dataBufferTwo: make([]uint8, 2),
}
}
// Configure sets up the device for communication.
func (d *Device) Configure(cfg Configuration) {
// Multipliers come from "Table 2. Mechanical characteristics" of the datasheet * 1000
switch cfg.AccelRange {
case ACCEL_2G:
d.accelMultiplier = 61
case ACCEL_4G:
d.accelMultiplier = 122
case ACCEL_8G:
d.accelMultiplier = 244
case ACCEL_16G:
d.accelMultiplier = 488
}
switch cfg.GyroRange {
case GYRO_250DPS:
d.gyroMultiplier = 8750
case GYRO_500DPS:
d.gyroMultiplier = 17500
case GYRO_1000DPS:
d.gyroMultiplier = 35000
case GYRO_2000DPS:
d.gyroMultiplier = 70000
}
data := make([]uint8, 1)
// Configure accelerometer
data[0] = uint8(cfg.AccelRange) | uint8(cfg.AccelSampleRate)
d.bus.WriteRegister(uint8(d.Address), CTRL1_XL, data)
// Configure gyroscope
data[0] = uint8(cfg.GyroRange) | uint8(cfg.GyroSampleRate)
d.bus.WriteRegister(uint8(d.Address), CTRL2_G, data)
}
// Connected returns whether a LSM6DSOX 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] == 0x6C
}
// 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_A, d.dataBufferSix)
x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * d.accelMultiplier
y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * d.accelMultiplier
z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * d.accelMultiplier
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)
x = int32(int16((uint16(d.dataBufferSix[1])<<8)|uint16(d.dataBufferSix[0]))) * d.gyroMultiplier
y = int32(int16((uint16(d.dataBufferSix[3])<<8)|uint16(d.dataBufferSix[2]))) * d.gyroMultiplier
z = int32(int16((uint16(d.dataBufferSix[5])<<8)|uint16(d.dataBufferSix[4]))) * d.gyroMultiplier
return
}
// ReadTemperature returns the temperature in celsius milli degrees (°C/1000)
func (d *Device) ReadTemperature() (int32, error) {
d.bus.ReadRegister(uint8(d.Address), OUT_TEMP_L, d.dataBufferTwo)
// From "Table 4. Temperature sensor characteristics"
// temp = value/256 + 25
t := 25000 + (int32(int16((int16(d.dataBufferTwo[1])<<8)|int16(d.dataBufferTwo[0])))*125)/32
return t, nil
}
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package lsm6dsox
// Constants/addresses used for I2C.
// The I2C address which this device listens to.
const Address = 0x6A
const (
INT1_CTRL = 0x0D
INT2_CTRL = 0x0E
WHO_AM_I = 0x0F
CTRL1_XL = 0x10 // Accelerometer control register 1 (r/w)
CTRL2_G = 0x11 // Gyroscope control register 2 (r/w)
CTRL3_C = 0x12
CTRL4_C = 0x13
CTRL5_C = 0x14
CTRL6_C = 0x15
CTRL7_G = 0x16
CTRL8_XL = 0x17
CTRL9_XL = 0x18
CTRL10_C = 0x19
STATUS_REG = 0x1E
OUT_TEMP_L = 0x20
OUT_TEMP_H = 0x21
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_A = 0x28
OUTX_H_A = 0x29
OUTY_L_A = 0x2A
OUTY_H_A = 0x2B
OUTZ_L_A = 0x2C
OUTZ_H_A = 0x2D
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
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
GYRO_SR_3332 GyroSampleRate = 0x90
GYRO_SR_6664 GyroSampleRate = 0xA0
)