First line follower

My first line follower, it uses a dspic33fj128mc802, 6 QRD1114 sensors, this motor driver http://www.sparkfun.com/products/9457 , this motors http://www.sparkfun.com/products/8911 (things that i win on the free day :D). i have already written the code for read the 6 sensors and obtain the line position and the motor driver part, now i'm tryng to write the pid routine. For read the sensor i use the scan capability of the pic and i take 10 sample of each channel and i do the average. The pic runs at almost 40 MIPS but i think that i will decrease the speed. the pwm frequency is 20 khz and the resolution is 12 bit.

update 18/04 : i finally write the pid code and now i am finding a way to set the three K.Soon a video of the proportional control not completely tuned

update 19/04: uploaded the video of the robot it uses a PD loop and the motor are at maximum speed.