What are I2C pins on Arduino Robot

Hi everyone,

I got a Arduino Robot recently and is trying to use its I2C function, but the thing is I cannot find correct I2C pins.

I found a layout here(Grappling with the Arduino Robot Control Board - Grappling with electronics), but it doesn't look right.

I turned on Robot and measured 4 I2C pins, there is 5V between SDA(+5V) and SCL(0V), other two pins are also +5V compare to SCL, that means there is no GND for I2C.

Is that right? Because all tutorials I found they connect SDA, SCL and GND between two boards.

Anyone can help me? thanks!

Any ground will do.


I tried using a GND from TK3, used 2 pull up resistors, and shared 5V between UNO and Robot, but still I2C didn't work.

And another thing I don't understand is that why there is 5V between SDA and SCL, because on UNO, there is no voltage between A4 and A5.


I'm sorry, I don't have a robot (hint, Massimo :wink: ) - I can only offer general advice.

No problem AWOL, thank you very much for your advice!!