I use the MCP2515 modules with Arduino Nano boards. Seven wires and you're reading CAN bus. With a Raspberry Pi and seven wires you can read and send CAN bus data, without writing a single line of code. Just attach it to a CAN bus, and run the candump program and pipe it to a file and you can sniff until the SD card fills up.These little $2 gadgets arrived today.
30.82US $ |10PCS MCP2515 CAN Bus Module TJA1050 receiver SPI For 51 MCU ARM controller|Integrated Circuits| - AliExpressSmarter Shopping, Better Living! Aliexpress.comwww.aliexpress.com
It's basically a CAN line driver and a MCP 2515 CAN module chip on a nice little board with SPI interface to a PIC.
So two of these together and one cheaper PIC might be better than two $$ CAN enabled Pics
Anyway more toys to play with..