RC-ify Your Lego Mindstorms

Lego Mindstorms is a wonderful concept that should open the way for countless robotic possibilities, but, at least in the NXT version, it is hindered by one thing: The programming language. The Lego Mindstorms programming language is terrible, so I decided to circumvent it, and make my robots radio controlled.

-Lego Mindstorms motors

-RC transmitter and receiver

-2 cell (7.4 V) LiPo battery

-2-3 RC motor controllers (ESCs)

In order to make these motors easily controllable, we will need to gain access to the motor leads. I found that the easiest way to do this was by cutting a motor cable in half. Then, use wire strippers to expose the white and black leads. these two are the important ones; they provide power to the motor, while the others are used for the encoder, which can be used with a microcontroller to execute precise movements.

Attach the output wires of your motor controllers to the red and white wires that you stripped in the last step. If your radio system can reverse its outputs, it doesn't matter which way you connect them, you can fix any reversed motors later. This is also when you should wire together the inputs of your motor controllers and attach a plug that matches your battery. Here, the polarity does matter. You DO NOT want to accidentally reverse the polarity of the connection between the battery and any motor controller, as it could kill the motor controller. Make sure that the positive wire from the battery connects to the positive input of the motor controller, and vice versa.

There are plenty of excellent designs for Lego Mindstorms robots out there, or, like I prefer to do, you can just start building and see what happens. Just make sure your robot has space to put all the electronics.

Now you have to get the electronics attached. Here, I usually end up using a lot of tape and rubber bands to hold everything in place. Zip ties also work well. The only thing to keep in mind is that you should be able to access the battery leads to plug, unplug, and charge the battery. If you haven't bound your receiver to your transmitter yet, you should do it now, while you can still easily access the bind button.

You now have a functional Lego Mindstorms robot. Build obstacle courses for it(I find that my cluttered desk works well for my tracked robot), add different accessories on to it, or get a friend to build one and have robot wars. The great thing about this robot is that it can be endlessly modified, combining the fun of RC with the versatility of Lego.