Troubleshooting
Start with the symptom you can observe. Apply one change at a time, then retry the smallest Quick Start example.
| Symptom | Check | Fix |
|---|---|---|
Arduino prints Error: BMM350 not connected, check wiring and I2C address! once a second | The Qwiic cable, or GND, 3V3, SDA and SCL on the header, and the address set by JP5 | Seat the Qwiic cable on both ends, or check each header wire. With JP5 moved to 0x15, pass the address: magSensor.begin(0x15). |
MicroPython stops with BMM350 not responding on address 0x14 | The wiring and the scl and sda pins in the I2C(...) line | Change the pins in the example to the ones you wired. With JP5 moved, create the sensor with BMM350(i2c, address=BMM350_I2C_ADSEL_SET_HIGH). |
MicroPython stops with BMM350 not found, chip ID ... was read instead of ... | A device answered at the address, but it is not a BMM350 | Check which devices on your bus use 0x14 (or 0x15) and give the BMM350 an address no other device uses. |
MicroPython stops with Board not recognized, enter I2C pins manually | Your code creates BMM350() with no I2C object, on a board the module does not recognise | Pass an I2C object with your pins, as the examples do: BMM350(i2c). |
| No output at all in the Serial Monitor | The baud rate in the Serial Monitor | Set it to 115200, the rate the examples use, and reset the board. |
The sensor answers on neither 0x14 nor 0x15 | JP5 after cutting it | The address pin must never float. Bridge one side of JP5 again. |
The interrupt example prints nothing after BMM350 connected! | The INT wire and the pin number in the example (2 on Arduino, 5 in MicroPython) | Connect INT to the pin in the example, or change the pin in the code. The pin must support interrupts and read the 1.8 V INT signal as high. |
| Readings show a large offset after a strong magnet was close | Whether the sensor saw more than 250 mT | Fields above 250 mT may shift the offset and sensitivity. Keep strong magnets away from the board. |
Still blocked?
Ask on the community forum. Include the following so someone can reproduce it:
- product name and SKU: Soldered 3-axis Magnetometer BMM350 Breakout,
333359 - controller board and software environment
- library or module revision
- complete error text or unexpected output
- connection method and power source
- a clear photo of the wiring