CAN Bus Controller

The MCP25625 (aka an MCP2515 with built-in transceiver), is an extremely popular and well-supported chipset that has drivers in Arduino and CircuitPython. It only requires a SPI port and one pin for chip-select at a minimum. You can use it to send and receive messages in either standard or extended format at up to 1 Mbps.

The MCP25625 uses the exposed SPI port (SCK, MOSI and MISO).

CAN Bus JST-PH Connector

On the front of the board is the JST-PH connector with the three pins for communicating with the CAN Bus standard. If you use one of our JST-PH 3-pin cables, black wire is ground, red wire is CAN H and white wire is CAN L.

• The left input on the JST-PH connector is common ground shared between the two CAN connections.
• H - the CAN high signal for the CAN Bus standard. It is connected to the middle pin on the JST-PH connector.
• L - the CAN low signal for the CAN Bus standard. It is connected to the right input on the JST-PH connector.

CAN Bus Jumper Pins

• INT - The interrupt pin for the MCP25625. This jumper is open/not connected by default. If you solder the jumper closed, it will connect the interrupt pin to A0.
• STBY - The standby pin for the MCP25625. This jumper is open/not connected by default. If you solder the jumper closed, it will connect the interrupt pin to A1.
• RST - The reset pin for the MCP25625. This jumper is open/not connected by default. If you solder the jumper closed, it will connect the reset pin to A2.
• CS - The chip-select pin for the MCP25625. This jumper is closed by default and connected to pin A3. You can cut this jumper to disconnect CS from A3 and solder a wire from the pad closest to the CS label on the board silk to a different pin.
• Trm - The terminator jumper for the MCP25625. The BFF has a 120 ohm termination resistor connected between H and L. You can disable (remove) the resistor by cutting the Trm jumper, if your bus is already terminated.