This page presents a CAN bus shield for Raspberry Pi 3. A 3D view of the board is presented below:
The CAN bus interface is build in two stages, the first one is a SPI to CAN converter based on the Microchip MCP2515. The converter is connected to the Raspberry Pi 3 with a SPI interface. The CAN bus side of the MCP2515 is connected to the CAN bus transceiver (MCP2562).
EAGLE PCB project, Solidworks files, BOM (Bill of Material), pictures, etc. can be downloaded here: