CAN - BUS is a common used industrial communication protocol for its hight reliability, long distance and mean data - rate. It is widely used for communication in automative area. CAN - BUS shield is a board allows arduinos to enter CAN bus. Moreover this board provides more than one Arduino boards on the same bus. SPI interfaced MCP2515 is designed based CAN controller and TJA1050 CAN tranciever. It is very easy to use with OBD - II library.
This MCP2115 CAN - SPI converter board has the same funcionallity with Arduino CANBUS Shield.