> Use two diodes. Point one at the LED, and the other away from the LED. > Use an opamp to get the difference between the two signals. I've seen detectors completely swamp in direct sunlight -- no response at all. The only solution I know of is to shade the detector and make sure the direct sunlight doesn't reflect off the sender. Perhaps that was the problem that Leonardo De Palo was getting at. The cheapest shade I've used was a piece of black plastic with the detector stuffed in one end of a threaded hole. The threads really seem to keep incident IR from bouncing around and the depth of the hole will (obviously) narrow the detectors field-of-view. Cheers, Win Wiencke Image Logic Corporation