Terminal Block Pins

On the front of the board are the three pins for the included 3.5 mm terminal block. It is outlined in white on the silk.

• L - the CAN low signal for the CAN Bus standard.
• Middle pin (unlabeled) - common ground shared between the two CAN connections
• H - the CAN high signal for the CAN Bus standard.

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

Power Pins

• Vcc - this is the power pin. Since the transceiver chip uses 3-5 VDC, to power the board, give it the same power as the logic level of your microcontroller - e.g. for a 5V micro like Arduino, use 5V.
• GND - common ground for power and logic.

CAN Logic Pins

• RX - CAN receive/input pin for boards with a CAN peripheral.
• TX - CAN transmit/output pin for boards with a CAN peripheral.

Check the product documentation for the board you are wiring this to, to make sure that:

1. The chip has CAN support
2. The RX and TX pins are brought out for you to connect the transceiver to

Despite sharing the 'RX' and 'TX' name with UART, they're not at all the same interface.

• SLNT - can be pulled high to put the TJA1051/3 transceiver into silent mode. In silent mode, the transmitter is disabled, releasing the bus pins to a recessive state.
• CANH - the CAN high signal for the CAN Bus standard.
• CANL - the CAN low signal for the CAN Bus standard.

Termination On/Off Switch

The board has two 60 ohm resistors (120 ohm in series) connected between CANH and CANL. You can disable the terminator by setting the Termination switch OFF, if your bus is already terminated. Otherwise, keep the switch set to ON to enable the termination resistors.