I'm building a c++ interface for the start.atmel.com generated SAME54 ASF Can drivers and I'm having some issues. At the moment I'm just trying to write a test message out to the bus. After the system_init (and thus can_init), registering a tx callback, and calling can_async_enable, I make periodic calls to can_async_write to send my test message. The first two writes complete without error except nothing appears on the bus, the callback is never called, and the message seems stuck in the tx fifo queue. After that the queue is full and all subsequent writes return ERR_NO_RESOURCE.
I do have another CAN device on the line, both are terminated. I also have a scope on the line. I think both are set at 250k baud although that's part of what I'm testing.
Any Atmel CAN wizards out there with ideas about what could cause the behavior I've described?