Servo - August 2010

The final product.

A view from above (note: in this orientation, the robot's front is at the top, and the rear is at the bottom).

Your First Program

Now that the chassis is built, it's time to experiment with a program or two. Plug the left drive motor into port B and the right drive motor into port C. Then, turn on the NXT and navigate to the NXT Program menu. This feature will allow you to create very simple programs for your robot, as opposed to the more complex computer-based software we'll be looking at next time.

The very first thing to try is to make the robot move forward and backward in a straight line. This is the robotic equivalent of a program that says "Hello World!" As your first step in the NXT Program editor, select the "Forward 5." Then select "Empty" for step 2; "Backward 5" for step 3; and "Empty" for step 4. Finally, choose "Loop" instead of "Stop," and press "Run" to see Eddie move for the first time.

Because we consider the drive wheels to be the front of the robot and the caster to be the back, Eddie actually drives backwards when you tell him to go forwards, and forwards when you tell him to go back. The reason for this is his gear train.