Terminal Block Pins

On the front left of the board, are the three pins for the included terminal block. It is outlined in white on the silk.

• CANL - the CAN low signal for the CAN Bus standard.
• - - common ground shared between the two CAN connections
• CANH - the CAN high signal for the CAN Bus standard.

Both CANL and CANH are connected to a 5V charge-pump voltage generator. Even if you are using 3.3V logic on a Feather board, it will generate a nice clean 5V as required by the CAN Bus transceiver.

Edge Launch DE-9 Connector Solder Pads

On the front-right end of the board are the solder pads for attaching an optional edge launch DE-9 connector. This is commonly used for connecting to CAN devices. CANL is connected to DE-9 pin 2 and CANH is connected to DE-9 pin 7. You could then plug this into an ODB-II cable to connect to a car's CAN network. Then, you can decode messages with software.

Terminator Jumper

The terminator jumper is located on the front of the board, to the left of the solder pads for the edge launch DE-9 connector. It is labeled TERM and is outlined in white on the board silk.

• TERM - The board has a 120 ohm terminator connected between CANH and CANL. You can disable (remove) the terminator by cutting the TERM jumper, if your bus is already terminated.

Reset Pin and Jumper

• Reset Jumper - located on the back of the board, to the right of the board name description, is the reset jumper. It is labeled RST and is outlined in white on the board silk. You can cut this jumper to disconnect the MCP2515 reset pin from the Feather reset pin.
• Reset Pin - located on the front of the board in the center. It is labeled RST on the silk. If you cut the reset jumper, you can use this pin to connect the MCP2515 reset pin to a different IO pin.

Chip Select Pin and Jumper

• CS Jumper - located on the back of the board, below Feather pin 5, is the chip select jumper. It is labeled CS and is outlined in white on the board silk. By default, the MCP2515 chip select pin is connected to pin 5 on the Feather. You can cut this jumper to disconnect the MCP2515 CS pin from Feather pin 5.
• CS pin - located on the front of the board in the center. It is labeled CS on the silk. If you cut the CS jumper, you can use this pin to connect the MCP2515 CS pin to a different IO pin.

Interrupt Pin and Jumper

• INT Jumper - located on the back of the board, below Feather pin 6, is the interrupt jumper. It is labeled INT and is outlined in white on the board silk. By default, the MCP2515 interrupt pin is connected to pin 6 on the Feather. You can cut this jumper to disconnect the MCP2515 INT pin from Feather pin 6.
• INT pin - located on the front of the board in the center. It is labeled INT on the silk. If you cut the INT jumper, you can use this pin to connect the MCP2515 INT pin to a different IO pin.

Silent Mode Pin

• SLNT pin - located on the front of the board in the center. It is labeled SLNT on the silk. This pin can be pulled high to put the TJA1051/3 transceiver into silent mode. From the datasheet:

In Silent mode, the transmitter is disabled, releasing the bus pins to recessive state. All other IC functions, including the receiver, continue to operate as in Normal mode. Silent mode can be used to prevent a faulty CAN controller from disrupting all network communications.