Freematics Forum

I have the ODB-II Model B adapter (labeled "UART adapter") and an Arduino Uno. According to this page: http://arduinodev.com/hardware/obd-kit/ Model B communicates via the SDA/SCL data lines (blue/yellow). Do I also need to plug in the Tx/Rx wires (in my case white/green) into Arduino's Rx/Tx ports, or are they irrelevant in the case of the Model B? Thanks.

There is no Rx/Tx for model B.

I assume you mean the answer is yes, the Tx/Rx wires of Model B should be plugged into Arduino's Tx/Rx port for proper operation, is that correct?

How many connectors do you have from the adapter?

I have 3 pairs of connectors: red/black (I assume it's +5V/GND), blue/yellow (I assume it's SDA/SCL) and white/green (I assume it's Rx/Tx). Images of my unit and connectors enclosed.

That's older version. Yes, Rx/Tx needs connected in this case.

Thanks. One more question... I'd like to debug my Arduino code at home, using an OBD emulator. Given that the Rx/Tx connectors need to be plugged in for this model to work, is there any way to print out debug messages through the serial port in Arduino's IDE? I assume that when the Rx/Tx ports on the Arduino are hooked up to something, no serial port communication to the IDE (or even uploading onto the Arduino) is possible.