The MCP2515 PICtail? Demo Board implements a simple CAN bus using two nodes. One node uses the MCP2515 Stand Alone CAN controller and the other node uses the MCP25020 CAN I/O Expander. Each node utilizes one input (push button) and one output (LED).
The boards demonstrate a simple, inexpensive implementation of a CAN bus. The MCP2515 node transmits its input (push button) information at regular intervals and request input (push button) information from the MCP25020 at regular intervals. An LED on each node reflects the state of the other node's push button.
Datasheet
