Hi everyone,
So, I have FDCAN working in internal and external loop back but when I connect it to an external CAN bus and switch it to standard operation I get nothing. I know there are messages on the CAN bus because I have a CAN scanner on the bus that is showing activity. However, the RX interrupt never goes off. My first debugging step was to remove the H7 from the bus and just see using an oscilloscope if the H7 was outputting anything (for loop with HAL_FDCAN_AddMessageToTxFifoQ and a 50ms delay) , I'm aware that two devices are needed for communication but from my understanding the FDCAN controller should still transmit until it reaches the ACK?
I then plugged in my CAN to USB converter connected directly to the H750B Discovery, I had a look at the signals before and after connecting the H750B and there was no change in the packets, they were the same if there was the single device (the CAN to USB converter) or if there was two devices, both the H7 and the CAN to USB converter. So it seams to me that the H7 is not ACKing or receiving the packet sent by the CAN to USB converter at all. This also seams to answer my previous question about what happens when there is only a singe device on the CAN bus, through I would not be surprised if my converter is doing something strange.
I'm very new to CAN and fairly inexperienced with embedded Dev as a whole, I did have CAN working well off a G474 nucleo with an external transceiver but that had less options to mess up in cubeMX.
I would apprecaite any help that could be thrown my way!
Cheers,
Michael
