Jose Da Silva wrote: >> transistor and maybe eight passives. I was wondering if I can build a >> quick-and-dirty wireless modem based on a super-reg, a one-transistor >> AM transmitter, and a modem IC. > > Sure you can. > You just finished saying you built a receiver 10 years ago. Good one. :-D If you weren't trying to be funny, I think there's more to a wireless modem than a superregenerative receiver. >> I have a project that requires a speed of only 1200 baud, half >> duplex, and a range of 10-15 meters. Frequency stability is a >> priority. > > Sounded okay until you said frequency stability is a priority, which > frequency needs to be stable? the regen or the 1200baud? Regen. > If you meant the regenerative receiver, no, you can't because by nature > a regen receiver locks to the strongest transmission, which is not > necessarily your own transmitter. Since we're talking about a 10-15 meter range, I can probably ensure that my transmitter is the loudest signal in the room. > Have your TX circuit send AM as you planned, and have your receiver > receive AM and send the AM into a comparator (some PIC chips have > comparators built in, for example pic16c620 ....but choose a more > updated chip since the 620 is no longer built). > Then have your pic chip generate the 1200baud. Hold on.. do you mean 1 = signal, 0 = no signal? That's not what I had in mind, I was thinking in terms of FSK or PSK amplitude-modulating the carrier. The simplified requirements are: I need two black boxes that would let me connect two terminals 10 meters apart, and allow communication at 1200 baud. I know you guys tend to assume there's a pic on each end that I can squeeze some modem code into, but that's not the case here. :-) I would prefer a "transparent" hardware solution, but if there is open source modem code for a low-end PIC, I would consider that as well. >> Or maybe there are less expensive real modem ICs out there? > > Probably, but I didn't look at any of the suggestions mentioned below. Links below are for transmitters/receivers and wireless modems, not modem ICs. Best regards, Vitaliy >> Alison Lewis wrote: >> > If you've been watching, there were some great RF >> > devices suggested to me, so I put the list together >> > for anyone else who may be looking for small RF >> > transmitters. I went with >> > http://www.rentron.com/remote_control/TXLC-315.htm. >> > >> > >> > www.sparkfun.com >> > http://www.radiotronix.com/products/prodrctas.asp >> > http://www.rentron.com/remote_control/TXLC-315.htm or >> > http://www.rentron.com/remote_control/TXLC-434.htm >> > www.rfsolutions.co.uk > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist