bmm150 — BMM150 3-axis magnetometer

Driver for the Bosch BMM150 3-axis geomagnetic sensor over I2C. On construction the driver soft-resets the device, switches it into normal operating mode at the requested ODR, and reads the trim registers used by the Bosch compensation equations to convert raw readings into calibrated magnetic-field values.

Note

SPI mode is not supported by this driver; passing a non-I2C bus raises ValueError.

Example:

import time
from machine import Pin, I2C
from bmm150 import BMM150

imu = BMM150(I2C(1, scl=Pin(15), sda=Pin(14)))

while True:
    print("magnetometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}".format(*imu.magnet()))
    time.sleep_ms(100)

Classes

class bmm150.BMM150(bus: machine.I2C, cs: machine.Pin | None = None, address: int = 0x10, magnet_odr: int = 30)

Construct a BMM150 instance, soft-reset the chip, verify its chip ID, configure it for normal mode at magnet_odr Hz and read the factory trim registers.

bus

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

cs

Reserved for SPI mode. Must be left as None; SPI is not currently implemented and supplying a non-I2C bus raises ValueError.

address

7-bit I2C address of the device. Defaults to 0x10.

magnet_odr

Magnetometer output data rate in Hz. Must be one of 2, 6, 8, 10, 15, 20, 25 or 30; anything else raises ValueError.

magnet_raw() → tuple[int, int, int, int]

Poll the data-ready flag and return the raw signed (x, y, z, hall) readings as integers, with the sub-LSB bits already shifted out. Raises OSError("Data not ready") if no sample becomes available within ten retries.

magnet() → tuple[float, float, float]

Read a fresh sample via magnet_raw() and return the compensated magnetic-field vector (x, y, z). The compensation uses the trim values read at construction and matches the reference C driver supplied by Bosch.