Alpha Rex

The last tutorial was to build Alpha Rex, a walking robot with very limited arm/hand movement. Again, I used the directions to build the robot, and programmed it myself using the visual programming program the NXT comes with. This robot uses all three motors (two for the legs, one to control the arms/hands), two touch sensors (to determine where the legs are), the ultrasonic sensor (to sense objects in front), and the light sensor (to determine the color of the ball in hand).

The robot must first be able to walk. Then, if an object is placed 25 cm or closer in front of the robot, it will stop and ask for a green ball. If a different colored ball is placed in its hand, or no ball at all, an error sound is played and it asks for green again. If it gets the green ball, it says thank you, and proceeds walking. (The color is bad on the video, so if you can't tell, I give the robot a red ball the first time, and a green one the second)

This is the last tutorial that directions were provided for with the NXT 2.0. I hope to start programming in an actual programming language when I can find one that works well with the NXT. The visual one, while intuitive for younger folks, can prove to be quite frustrating in its simplicity, time consuming and limiting.

Ball Sorter

For the next tutorial, I again used the directions to build the machine, and did the programming myself. The Ball Sorter uses two motors, the color sensor, and two touch sensors, according to the directions. I found it necessary only to use one of the touch sensors. The object is to have the machine dispense each ball and sort them appropriately by color into the bins. Here's the video!

Gatorbot

The next tutorial was the Gatorbot...not especially an exciting one, so I'm glad to be done with it. Basically the robot will lunge forward at an object closer than 60 cm, begin biting at it when it is closer than 20 cm, then retreat for a period of 6 seconds. Unfortunately the feet don't grab hold of the tile flooring so the gator doesn't move all that well backwards. Here it is!

Protector Bot

Last night I figured I should actually go through some of the tutorials and challenges to learn how to build and program with the NXT. The first challenge is the "Protector Bot." Again, I used the directions to build the Lego vehicle, and figured out how to program the robot myself.

The Tutorial Challenge:
The robot must spin in a circle monitoring the room for objects which are 40 cm or closer. While object free, the robot will continue to spin with a green light emitting from its lamp.

When an object comes within the range, the bot must stop, turn the lamp blue as a warning, and emit a warning sound.

If the object moves out of the way within 2 seconds, the bot will return monitoring in a circle with a green light. If the object does not move away, the light will turn red and the bot and fire at the object every 2 seconds until it moves away.

Here's the video!

First Project: Follow the Black Line

I'm a professional musician and have always had an interest in math and science. Looking for another outlet to spark my creative juices and fill some down time I decided to order a Lego Mindstorms NXT 2.0 robotics kit. A couple nights ago I it came in the mail. That night I quickly assembled the Quickstart vehicle using the directions. Always wanting to run before I can walk, I then decided I wanted to see if I could figure out the programming interface without reading the directions and how to program the robot to follow a black line. Here the video of what I came up with!