ICM-20948 I²C Communication Issue with MAMWLE-02/03 (STM32-based)

By jayasreetech27com , 17 June 2025

I am currently working on a project involving your ICM-20948 9-axis IMU sensor interfaced with a MAMWLE-02/03 module (based on STM32, using 1.8V I/O) over the I²C bus. However, I am encountering persistent communication issues.

Issue Description:
When I perform an I²C scan, the sensor does not respond at the expected address (0x68 with AD0 low or 0x69 with AD0 high). In some cases, a random or undefined address appears, or no device responds at all.

Hardware Setup:
Host Controller: MAMWLE-02/03 (STM32-based, 1.8V logic)

Sensor: ICM-20948

I²C Lines: PB11 (SDA) and PB10 (SCL)

AD0 Pin: Connected to PB14 (set HIGH or LOW to change I²C address)

I²C Pull-Ups: 10kΩ to 1.8V

Power Supply: 1.8V to both VDD and VDDIO of the IMU

Bus Voltage: Verified 1.8V idle on SDA and SCL

Code: Tested with basic I²C scanner and WHO_AM_I register read (0x00)

Additional Notes:
This issue occurs on our newer hardware revision.

A previous board with identical design works properly.

I’ve verified correct wiring, soldering, and power delivery.

No response is received from the WHO_AM_I register.

Could you please advise on any known startup requirements, signal conditioning needs, or potential manufacturing issues related to ICM-20948? I’m open to providing the schematic and test code for deeper analysis if needed.

Looking forward to your support.

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