AnsweredAssumed Answered

Problem with I2C on PA8 and PC9

Question asked by Markus on Jul 10, 2014
Latest reply on Jul 11, 2014 by waclawek.jan
Hello,

i tried to use I2C3 on PA8 and PC9. I noticed that i can send data over the i2c bus but the stop condition was not working.
So the bus never came back. After some investigation i found that the SCL line starts oscillating with 16MHz (I use the HSI oscillator).
I checked the RCC MCO settings and noticed that it is set to HSI output. When i change the prescaler i can change the frequency.
Since i use a STM32F407VGT6 i am not able to use alternative pins. Is there any workaround to avoid MCO to overtake the I2C lines?

 stm32f4-i2c4.png

stm32f4-i2c.png

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