I am looking to create a sensor device that can detect and edge of a paper. For example say we have a plain surface with a 1mm black line and if a piece of paper was to cross this line then an LED should flash.
There are multiple ways to detect this. detect a lessening of reflected lightdetect thickness of the paperdetect loss of signal from IR (or other) xmit/rcv pairWhat is it you're actually wanting to sense? What's the significance of the black line?
The 1mm line is important to ensure that it is perfectly aligned.
| | | | | | interruptor 1 >|---------|< interupptor 2leading edge of paper ^