Pid ?
 

Hi im trying to do a PID controller using 8051 - 89C52 ,im trying to do it for getting straight line motion , and if its worked im gonna use it for odometry rather than following line in the contest ..etc , i need some sample codes .. or other ideas for staright line motion , some of ya suggested pwm the motors or connect var resistor but when putting a load it affects the motion.
thanks,

http://www-personal.umich.edu/~johan...rs/umbmark.pdf

I recommend you to read this paper. To go straight, it doesn't only depend on controllers but also to wheel base and diameters.

Goodluck.

thanks for reply , i seen vietnameese robocon videos , really WOW, meachanics very nice and also the control , i've seen that the robots move smoothly , how do you accomplish that ?? you use used dc motors or new ? and from where do you buy them ??
and i'd like to know how do you make the robot rotate 90 Degrees and 180 Degrees and the counter ?? i've made the line follower , would you tell me ur opinion ??

http://www.youtube.com/watch?v=TRE3nyajzcs
http://www.youtube.com/watch?v=0Ca1j7P9H98