lsm9ds1

Documentation

Overview

LSM9DS1, 9 axis Inertial Measurement Unit (IMU)

Datasheet: https://www.st.com/resource/en/datasheet/lsm6ds3.pdf

Index

• Constants
• type AccelBandwidth
• type AccelRange
• type AccelSampleRate
• type Configuration
• type Device
  • func New(bus drivers.I2C) *Device
  • func (d *Device) Configure(cfg Configuration) error
  • func (d *Device) Connected() bool
  • func (d *Device) ReadAcceleration() (x, y, z int32, err error)
  • func (d *Device) ReadMagneticField() (x, y, z int32, err error)
  • func (d *Device) ReadRotation() (x, y, z int32, err error)
  • func (d *Device) ReadTemperature() (t int32, err error)
• type GyroRange
• type GyroSampleRate
• type MagRange
• type MagSampleRate

Constants

const (

	// Constants/addresses used for I2C.
	ACCEL_ADDRESS = 0x6B
	MAG_ADDRESS   = 0x1E

	// Table 21. Accelerometer and gyroscope register address map
	WHO_AM_I     = 0x0F // value 0x68
	CTRL_REG1_G  = 0x10
	OUT_X_L_G    = 0x18
	OUT_X_H_G    = 0x19
	OUT_Y_L_G    = 0x1A
	OUT_Y_H_G    = 0x1B
	OUT_Z_L_G    = 0x1C
	OUT_Z_H_G    = 0x1D
	OUT_TEMP_L   = 0x15
	OUT_TEMP_H   = 0x16
	CTRL_REG6_XL = 0x20
	STATUS_REG   = 0x27
	OUT_X_L_XL   = 0x28
	OUT_X_H_XL   = 0x29
	OUT_Y_L_XL   = 0x2A
	OUT_Y_H_XL   = 0x2B
	OUT_Z_L_XL   = 0x2C
	OUT_Z_H_XL   = 0x2D

	// Table 22. Magnetic sensor register address map
	OFFSET_X_REG_L_M = 0x05
	OFFSET_X_REG_H_M = 0x06
	OFFSET_Y_REG_L_M = 0x07
	OFFSET_Y_REG_H_M = 0x08
	OFFSET_Z_REG_L_M = 0x09
	OFFSET_Z_REG_H_M = 0x0A
	WHO_AM_I_M       = 0x0F // value 0x3D
	CTRL_REG1_M      = 0x20 // TEMP_COMP OM1 OM0 DO2 DO1 DO0 FAST_ODR ST
	CTRL_REG2_M      = 0x21 // 0 FS1 FS0 0 REBOOT SOFT_RST 0 0
	CTRL_REG3_M      = 0x22 // 0 LP 0 0 SIM MD1 MD0
	CTRL_REG4_M      = 0x23 // 0 0 0 0 OMZ1 OMZ0 BLE 0
	STATUS_REG_M     = 0x27
	OUT_X_L_M        = 0x28
	OUT_X_H_M        = 0x29
	OUT_Y_L_M        = 0x2A
	OUT_Y_H_M        = 0x2B
	OUT_Z_L_M        = 0x2C
	OUT_Z_H_M        = 0x2D

	// Table 67. CTRL_REG6_XL register description
	ACCEL_2G  AccelRange = 0b00
	ACCEL_4G  AccelRange = 0b10
	ACCEL_8G  AccelRange = 0b11
	ACCEL_16G AccelRange = 0b01

	// Table 68. ODR register setting (accelerometer only mode)
	ACCEL_SR_OFF AccelSampleRate = 0b000
	ACCEL_SR_10  AccelSampleRate = 0b001
	ACCEL_SR_50  AccelSampleRate = 0b010
	ACCEL_SR_119 AccelSampleRate = 0b011
	ACCEL_SR_238 AccelSampleRate = 0b100
	ACCEL_SR_476 AccelSampleRate = 0b101
	ACCEL_SR_952 AccelSampleRate = 0b110

	// Table 67. CTRL_REG6_XL register description
	ACCEL_BW_50  AccelBandwidth = 0b11
	ACCEL_BW_105 AccelBandwidth = 0b10
	ACCEL_BW_211 AccelBandwidth = 0b01
	ACCEL_BW_408 AccelBandwidth = 0b00

	// Table 45. CTRL_REG1_G register description
	GYRO_250DPS  GyroRange = 0b00
	GYRO_500DPS  GyroRange = 0b01
	GYRO_2000DPS GyroRange = 0b11

	// Table 9. Gyroscope operating modes
	// Table 46. ODR and BW configuration setting (after LPF1)
	GYRO_SR_OFF GyroSampleRate = 0b000
	GYRO_SR_15  GyroSampleRate = 0b001
	GYRO_SR_60  GyroSampleRate = 0b010
	GYRO_SR_119 GyroSampleRate = 0b011
	GYRO_SR_238 GyroSampleRate = 0b100
	GYRO_SR_476 GyroSampleRate = 0b101
	GYRO_SR_952 GyroSampleRate = 0b110

	// Table 114. Full-scale selection
	MAG_4G  MagRange = 0b00
	MAG_8G  MagRange = 0b01
	MAG_12G MagRange = 0b10
	MAG_16G MagRange = 0b11

	// Table 111. Output data rate configuration
	MAG_SR_06 MagSampleRate = 0b000
	MAG_SR_1  MagSampleRate = 0b001
	MAG_SR_2  MagSampleRate = 0b010
	MAG_SR_5  MagSampleRate = 0b011
	MAG_SR_10 MagSampleRate = 0b100
	MAG_SR_20 MagSampleRate = 0b101
	MAG_SR_40 MagSampleRate = 0b110
	MAG_SR_80 MagSampleRate = 0b111
)

Types

type AccelBandwidth

type AccelBandwidth uint8

type AccelRange

type AccelRange uint8

type AccelSampleRate

type AccelSampleRate uint8

type Configuration

type Configuration struct {
	AccelRange      AccelRange
	AccelSampleRate AccelSampleRate
	AccelBandWidth  AccelBandwidth
	GyroRange       GyroRange
	GyroSampleRate  GyroSampleRate
	MagRange        MagRange
	MagSampleRate   MagSampleRate
}

Configuration for LSM9DS1 device.

type Device

type Device struct {
	AccelAddress uint8
	MagAddress   uint8
	// contains filtered or unexported fields
}

Device wraps connection to a LSM9DS1 device.

func New

func New(bus drivers.I2C) *Device

New creates a new LSM9DS1 connection. The I2C bus must already be configured.

This function only creates the Device object, it does not touch the device.

func (*Device) Configure

func (d *Device) Configure(cfg Configuration) error

Configure sets up the device for communication.

func (*Device) Connected

func (d *Device) Connected() bool

Connected returns whether both sensor on LSM9DS1 has been found. It does two "who am I" requests and checks the responses. In a rare case of an I2C bus issue, it can also return an error. Case of boolean false and error nil means I2C is up, but "who am I" responses have unexpected values.

func (*Device) ReadAcceleration

func (d *Device) ReadAcceleration() (x, y, z int32, err error)

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 (*Device) ReadMagneticField

func (d *Device) ReadMagneticField() (x, y, z int32, err error)

ReadMagneticField reads the current magnetic field from the device and returns it in nT (nanotesla). 1 G (gauss) = 100_000 nT (nanotesla).

func (*Device) ReadRotation

func (d *Device) ReadRotation() (x, y, z int32, err error)

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 (*Device) ReadTemperature

func (d *Device) ReadTemperature() (t int32, err error)

ReadTemperature returns the temperature in Celsius milli degrees (°C/1000)

type GyroRange

type GyroRange uint8

type GyroSampleRate

type GyroSampleRate uint8

type MagRange

type MagRange uint8

type MagSampleRate

type MagSampleRate uint8