Hi i am a professional embedded design engineer I designed many circuits and their PCB's.......... I designed a same project that you need its a packing system. A conveyor belt moves and when the object approaches the predefined point it cuts the laser that falls on a light detector, the light sensor passes the information to microcontroller and than the microcontroller deactivates the conveyor motor.... Their are total four laser beams at multiple points that stops the conveyor..... Check out the project hardware and PCB on my profile........ Please feel free to contact me and discuss more about the project....
ABOUT ME:
I am a professional PCB and Circuit Designer. I designed many circuits and their PCB's. I also do programming of microcontrollers and their interfacing with different electronics components. I have experience in Pic,8051, Arduino, Atmel etc. I did many Projects using Arduino(Uno,Mega,mini etc).
I am Running a Website Under the name www . microcontroller-project . com You can see my work on it. Their are lot of Projects on it using different microcontrollers.