8 years, 4 months ago.

Multi i2c port problem in nucleo library or two broken accelometers?

In my system lcd st7920 via spi and compass HMC5883L via i2c works. However, I have two accelometer modules: adxl345 that does not work with i2c or spi and MMA7455 that does not work with i2c (spi i have not tested).

I have tried all i2c ports in my f401re with no luck and with several test software. I can not get any ACK from these 2 accelometer modules even if i try them with no other modules connected to the board.

Any ideas about the problem or did I just buy 2 broken accelometer modules?

Both accelometer modules are manufactured by http://www.lctech-inc.com/Hardware/. Does this company have quality problems?

Question relating to:

Affordable and flexible platform to ease prototyping using a STM32F401RET6 microcontroller.

2 Answers

8 years ago.

Hi. Please show the code of your project.

8 years, 4 months ago.


Did you try with the latest mbed version (v89) ? Because corrections in I2C have been done to fix an issue with multiple I2S slaves.


Of course I have the latest mbed version, v89.5525...

Update: ADXL345 via i2c is working now. The sdo/alt_address pin was not connected to anything and with a resistance meter it looked like it was grounded but it was not. I grounded sdo pin with nucleo DigitalOut pin and i2c connection is ok. (mma7455 seems to be dead and its resolution is only 8g while adxl345 has 16g, bad buy)

Does the i2c repeat condition work and what is the status of i2c single byte read and write methods?

posted by Compass Developer 17 Sep 2014