CAN on 18F4680 [Solved]

[Fredrik]

Problem solved!

So i finally found the error after I spent three days debugging. The fault was found on the development board from Basic Micro. The wire connector for B3 (canrx pin) had no connection to pin 36 (canrx) on the mcu. Instead of connecting canrx to the wire connector it had been connected to an analog multiplexer ic. Don't ask me why.

Of course I should have checked the development board in the first place. When it was delivered to me the analog multiplexer and rs-232 ic's had been swapped causing absolutely nothing to work. I had to swap them. But this isn't the first things you check when everything else seems to work.

So what happened was that canrx pin where driven low even though I measured a high signal. I just didn't measure directly at the pin of the mcu. Lesson learned.

And by the way: Don't buy products from BasicMicro, unless you want some extra work.