this is a very simple very fast robot built on an old tyco scorcher R/C car. it is in its first stage. I have used the oopic controller because of its simplicity. the motor driver is a lynxmotion board. and the sensor is a sharp IR ranger. The IR sits atop a servo that pans right to left and checks the distance of objects every 2 degrees of servo travel. its main function right now is non collision. the main problem i had to overcome was the timing of a direction change. the motors are very high torque. so alot of timing went into the programming. another problem was the motor driver. i needed 4 PWM signals to control speed and direction. the oopic only supplies 2 PWM signals. so i used an NOR chip and created a control circuit to use the 2 PWM to control all 4 lines. The PWM hooked up to inputs on 2 NORs. depending on the other two NOR inputs, i was able to use the PWM on all 4 lines. so far, only about 20 hours have been spent on this robot. and low cost is important to me. so far i have spent about 50 dollars. i got the tyco scorcher on ebay for 5 dollars. of course i had to fix it. the next stage for scorch is to add sonar and some more IR rangers. it will then be used strictly for cat chasing. Email: robotics80@hotmail.com