I literally used the sample code. Didn’t change anything. I did end up making use of a competitor’s CAN bus shield… I soldered jumpers to pins 1 and 4 of the mcp2551 transceiver and then connected those to the CAN controller port of a chipKIT max32.
The real trick with the max32 was to set up the CAN clock correctly. I am wondering if there’s a problem with the sample code all over the internet for the mcp2510. On the max32, it wasn’t enough to set the baud to 500k, I also had to use a bit calculator and adjust the quanta timing vales. As I have this working, I’ll revisit the mcp2510-based can shields later…