hello
quick question - was wondering if anyone had much experience getting a good infra red signal working over a 2 metre range... need to build a circuit using ideally an infra-red emitter and receiver that can work across a 2 metre range and give an interrupt every time the beam is broken, i have done this kind of project before but never across such a long distance and am having problems getting a consistent result. I have played with the sonar sensors which work well across this range but annoyingly enough i need to retrofit this into a door frame which has a pair of 2 core cable running to either side, so need to use some kind of transmitter / receiver setup which only uses 2 wires for each one. any ideas?
thanks in advance