LEGO® Answers is a question and answer site for LEGO® and building block enthusiasts. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I know almost nothing about robotics, so I was wondering how can I power the nxt motor without using the nxt brick, and how can I send signals to it?

share|improve this question

I think the simplest way is to use an NXT Converter Cable (Available from Bricklink). This has an NXT connector on one end and the standard 9v connector on the other. You can connect the 9v connector to any 9v battery box, (e.g. Battery Box with Switch (9V)) and, depending on the polarity, power the NXT motor forward or backward.

Now, the issues:

  • The speed of the motor is determined by the strength of your batteries. With new batteries the motor will run at full speed and you have no ability to vary this speed. Off/forward/backward are your only options.
  • There is no way to receive feedback from the motor, so no way to control the number of rotations as you can when connected to an NXT.
share|improve this answer
You can vary the speed if you use an old 9V transformer, or the PF battery (with yet another adapter cable). – Joubarc Sep 10 '12 at 4:27

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.