Lego NXT Motor + Arduino motor shield


I have 2 lego Mindsorm NXT motors like those one: I have cut a lego cable and I have found the schema if the cable for the motor here: Cable schema

I have a arduino motor shield like this: I have found the official documentation here: Official documentation i have also found an example here: Instructable info

And i would like to be able to: - Move my motors in both direction - Control the speed - Check the current position (if possible)

But I really don't understand how to do that witht the motor shield. If I put a simple tranfo 7,5V on the white cable and the black cable the motor turn in a direction. If I invert I move in the opposit direction. If I change the voltage the motor turn slower.

I have connect my transfo on the blue connector on the right side.

Thanks for helping me.


And i would like to be able to: - Move my motors in both direction


  • Control the speed


  • Check the current position (if possible)

Possible but difficult especially with your state of knowledge.

To make the motor move connect the black and white wires to the motor wires of the shield. You will then be able to control the motor like any other and also change the speed like you can with any other motor. Note the motor needs driving with 9V, but you can get away with 12V.

To get at the sensors connect pin 3 to ground (confusingly red) and pin 4 (green) to 5V. Then connect pins 5 and 6 ( blue and yellow ) up to the Arduino like a rotary shaft encoder.

This will allow you to read the position.