I have a prototype device that is listening to the canBus for certain messages (there are only two nodes on the bus, my device, and the sending device). I'm having a problem where the sender constantly sends the same message, I think because the ACKs that I'm sending aren't being 'recognised', so the sender keeps retrying. I think it's because of this that my microcontroller is not picking up the messages (firing the can receive interrupt).
I also have another device which seems to work correctly and ACKs the message and it is not retried.
I have included a screenshot of the scope trace. The yellow trace is what the microcontroller is transmitting, and the red trace is what is being received from the CAN IC on the PCB. v8 is the broken version (note that directly after the ACK, the message is resent). v7 is the correct working version. There's a slight difference in the waveform between the two but I don't know what it means.
Thanks for your help.