Make your own free website on
Line Follower ROBOT
Plermjai Inchuay,
Award winner from VingPeaw Competition 2543, the robot built with 2051, L293D, and four IR sensors. Simple circuit and platform, quick tracking and easy-understand program using C language.

I designed my 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.

Fig 1. Circuit diagram of my Robot.

Fig 2. Circuit diagram of Infrared sensors and comparators.

Fig 4.  Position of sensors,  left hand side is side view and right hand side is top view.


Software for write to AT89C2051 is robot1.hex ,which was written by C-language ,the  source code is robot1.ccompiled by using MC51 in TINY model with my start up code robot.asm .

MPEG files

Sample of competition between 2051 and 68HC11.

  • movie1.mpg (1,303kB)
  • movie2.mpg (373kB)