Plermjai Inchuay the award winner from VingPeaw Competition 2543 built the robot with 2051, L293D, and four IR sensors. Simple circuit and platform, quick tracking and easy-understand program using C language.
The author designed the Robot, which use two motors control rear wheels and the single front wheel is free. It has 4-infrared sensors on the bottom for detect black tracking tape, when the sensors detected black color, output of comparator, LM324 is low logic and the other the output is high. Microcontrollor AT89C2051 and H-Bridge driver L293D were used to control direction and speed of motor.
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