I'm trying to interface with an OV7725 image sensor. Omnivision has their SCCB which is very similar to I2C but does not generate an ACK bit. It seems like the STM32F407 (and maybe others in the product line, but that's what I have right now) gets into a state where it does not want to send any more data once it does not get the ACK it wants after the address is sent. So what's happening is when I send the address and don't get an ACK, I can't send any more data, even if I clear the AF bit and keep writing things to the DR register. Is there some way to make it ignore the no-ACK? Or am I doing something wrong?