Stm32wb15ccu i2c bus never has signal edges

[YGail.2]

I design a custom board including a stm32wb15ccu where I want to use the I2C bus. I have for SDA and SCL 10k pull up resistors. However when launching i2c the signal of SDA and SCL remain at 3.3V, no bus signal. Hence I could not communicate between the MCU and its slaves. ​pin 5 is SCL and pin 6 is SDA.

What I did so far to get the cause:

• Connected an external nucleo to the i2c pin headers , this worked perfectly fine.
• Resoldered the MCU chip multiple times
• Desoldered the pull up resistors, if somewhere 3V3 is shorted to the i2c. What I found interesting when desoldered the pull up resistors the voltage of the ​i2c is still at 0.2V instead of zero.

What I suppose a possible cause:

• Partly damage of the MCU
• Design error, wrong pin selected for I2C on the WB​

TThanks in advance for any help

[Foued_KH · Accepted solution]

Hello @Community member​ ,

You can try to check with an I2C example from the STM32 CubeFW :

STM32Cube_FW_WB_V1.15.0\Projects\NUCLEO-WB15CC\Examples\I2C

Foued

[Michael E]

Hello @Community member​ ,

You can also try with this very simple example on the wiki

Michael