My project involves making a laser based position finder for self guided vehicles. I will be placing my laser source and the detector circuit over a stepper motor which will be rotating.I will place 2 predefined reflective targets. I need help for 1. Detecting the targets using the pulses produced from the mirrors with black strips atached to it and 2. Traingulation algorithm to find the exact position of the vehicle.For this i need to set a reference point for the stepper motor.I am using ATMEL 89S8252 microcontroller. Thanx for the help in advance harish