STM32F415 weird I2C behaviour
thanks for all the suggestions. I found the solution and it's kind of weird. It works correctly on both boards, but on the STM32F415 it does not work with the logic analyzer capturing the data. On the F407 it does not matter. It's kind of a heisenbug, it does not happen if I don't look, but I had to look to know if it is working.