I still think it'll be easier if you make "on" be 40khz (detectable by IRRC receivers) or audio frequency (detectable by Scott's DTMF code or similar?) rather than just on/off. "blips" of several khz light look just like low frequency blinking to human eyes, and you get rid of having to filter out ambient light (maybe?) BillW -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.