lsm9ds1 — LSM9DS1 9-axis IMU

Driver for the ST LSM9DS1 iNEMO inertial module over I2C. The LSM9DS1 combines a 3-axis accelerometer, 3-axis gyroscope and 3-axis magnetometer in a single package; the accelerometer and gyroscope share an I2C address while the magnetometer responds on a second address. This driver also enables the on-chip 16-deep gyro/accel FIFO so that the most recent samples can be drained efficiently through iter_accel_gyro().

Example:

import time
from machine import Pin, I2C
from lsm9ds1 import LSM9DS1

imu = LSM9DS1(I2C(1, scl=Pin(15), sda=Pin(14)))

while True:
    print("Accelerometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}".format(*imu.accel()))
    print("Magnetometer:  x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}".format(*imu.magnet()))
    print("Gyroscope:     x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}".format(*imu.gyro()))
    time.sleep_ms(100)

Classes

class lsm9ds1.LSM9DS1(bus: machine.I2C, address_imu: int = 0x6B, address_magnet: int = 0x1E, gyro_odr: float = 952, gyro_scale: int = 245, accel_odr: float = 952, accel_scale: int = 4, magnet_odr: int = 80, magnet_scale: int = 4)

Construct an LSM9DS1 instance, verify the WHO_AM_I registers of both sub-devices, configure all three sensors and enable the accel/gyro FIFO in continuous mode.

bus

A configured machine.I2C bus the sensor is attached to.

address_imu

7-bit I2C address of the accelerometer/gyroscope sub-device. Defaults to 0x6B.

address_magnet

7-bit I2C address of the magnetometer sub-device. Defaults to 0x1E.

gyro_odr

Gyroscope output data rate in Hz. Must be one of 0 (off), 14.9, 59.5, 119, 238, 476 or 952.

gyro_scale

Gyroscope full-scale range in degrees-per-second. Must be one of 245, 500 or 2000.

accel_odr

Accelerometer output data rate in Hz. Same set of values as gyro_odr.

accel_scale

Accelerometer full-scale range in g. Must be one of 2, 4, 8 or 16.

magnet_odr

Magnetometer output data rate in Hz. Must be one of 0.625, 1.25, 2.5, 5, 10, 20, 40 or 80.

magnet_scale

Magnetometer full-scale range in gauss. Must be one of 4, 8, 12 or 16.

calibrate_magnet(offset: tuple[float, float, float]) → None

Write a hard-iron offset vector into the magnetometer’s OFFSET_REG_*_M registers. The offset is given in the same units as magnet() returns (gauss); each component is converted to raw LSBs using the configured magnetometer scale before being written.

gyro_id() → bytes

Return the single-byte WHO_AM_I register value of the accelerometer/gyroscope sub-device.

magent_id() → bytes

Return the single-byte WHO_AM_I register value of the magnetometer sub-device.

gyro() → tuple[float, float, float]

Return the gyroscope vector (x, y, z) in degrees per second.

accel() → tuple[float, float, float]

Return the acceleration vector (x, y, z) in units of standard gravity (1 g = 9.81 m/s²).

magnet() → tuple[float, float, float]

Return the magnetic-field vector (x, y, z) in gauss.

iter_accel_gyro() → Iterator[tuple[tuple[float, float, float], tuple[float, float, float]]]

Generator that yields (gyro, accel) tuples for every sample currently available in the FIFO and stops once the FIFO is empty. Each component vector has the same units as gyro() and accel() respectively.