MinIMU-9 + stm32f107


I’m using a MinIMU-9 with stm32f107 (3.3V @ Vin, Vdd disconnected). Most of the times, I2C communication fall at START condition (speeds from 100000 to 400000) other times I2C communication is working. stm32f107 has got a 3.3V i2c (olimex stm32-h107) with no pullups. I used MinIMU-9 on arduino mega2560 with almost the same code and it’s working. Could be a level-shifters problem? Tx.


Hello, Angelo.

Just to be sure, are you using a MinIMU-9 v2? If you are, it should be safe to connect 3.3 V directly to VDD instead of VIN (and leave VIN disconnected), although I am not sure if it will make much difference in your setup.

Does it work better if you use a slower I2C frequency? Do you have an oscilloscope or logic analyzer you can use to see what is happening on the I2C lines?

- Kevin


I’ve got an imu01b, I tried to connect Vdd as stated in the MinIMU page but without success, I think it’s an stm32 problem as sometimes when micro start SDA = 3.3V and SCL = 0V or inverted and start condition never happen…

Tx for answer