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[Solved] STM32F4 I2C Master Clock Stretching Fail

Question asked by Kyle Klumper on Sep 26, 2017
Latest reply on Oct 2, 2017 by Amel N

Hi there,

 

I am attempting to get an STM32F411CE microcontroller to interface with a BNO055 IMU using the I2C peripheral. This particular IMU uses clock stretching which doesn't seem to work with the HAL_I2C library that was auto-generated from STM32CubeMX. See image below:
I attached a second I2C device to the bus and was able to communicate with the library so I'm pretty sure it is only the clock stretching that is causing an issue.
As a reference, here is a waveform of an Atmel microcontroller interfacing with the same BNO055 device and it appears to be working as intended:
Any ideas on what could be causing this issue?
Thanks,
Kyle

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