How does one connect the MCP2551 bus transceiver to the CAN bus?
I see the pinouts of the OBD-II connector in this post:
Does one just connect CANL -> CANL and CANH -> CANH? Do we need to connect anything else, e.g. ground?
For instance, say one is using the AVR-CAN dev board from olimex. I see from the schematic
of this board,
MCP2551 CANL -> DB9 pin 2
MCP2551 CANH -> DB9 pin 7
From the other post, say we want to listen to the EV bus. We have EV CAN-L (12), EV CAN-H (13) on the OBD-II connector.
So do we just connect
(MCP2551 CANL -> DB9 pin 2) -> EV CAN-L (OBD-II 12)
(MCP2551 CANH -> DB9 pin 7) -> EV CAN-H (OBD-II 13)
Is this correct? Any other signals need to be connected?
I noticed from the schematic of the AVR-CAN board that there is a 120 resistor between CANH and CANL, but it doesn't seem to be connected across jumper pad CAN_T. Am I correct, or is there really a 120 ohm resistor connected between CANL and CANH. Can someone who owns this board verify for me?
Thanks in advance.