On Sun, 30 May 1999 12:39:01 +0000 Marc writes: >> At your very low data rate and very short required range, I think >that >> simply pulsing a PIC pin at RF frequencies might work. This would >have >> the advantage of a VERY low parts count. However, it would have the >> disadvantage of requiring you to run your PIC at frequencies which >are >> much higher than usual for such a low-power circuit. > >A really crazy idea: > >Clock the PIC AT your RF frequency! Make the CLOCK PCB traces LONG >and use THEM as antenna!!! Put the PIC asleep for a 0 (18ms), or >stay running a loop to transmit a 1. > >Using RC clock, the startup time is very short. Interesting idea... And what would you do for a receiver? I also wonder about having a loop (an inductor) and a capacitor in series between an output pin and ground. Changing state should result in a damped oscillation at the resonant frequency of the LC. The timing of these RF pulses could be varied to send useful information. Again, I don't know what would be a good receiver. Also, I seem to recall an FCC prohibition of "damped wave" transmissions... I'm away from my web access right now, but I think there's such a prohibition in part 15 somewhere. Harold ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866]