Line Follower using ATMEGA 8535

[oracion]

line follower atmega 8535

i build a line following robot for local competition and nearly finished. But i think it runs too "zig-zag" even in a straight line and even more in a curve. Someone told me to use PID algorithm in my Robot but i don't know how to. Would some one tell me how.
Here is my robot's spec:
-7 IR sensor
-ATMEGA 8535
-Dual full bridge dc motor driver using L298
-2 DC motor form Tamiya
Thanx..

 

[eehero]

line follower using atmega8

am interesting in ur topic and am waiting with u friend. to use PID vgood topic