Hello,

Because they are discontinued by the manufacturer or too expensive and I want to stay at very low cost.

I've check for the TCM3105 and some other. If they are not discontinued, the crazy vendor ask me 20 to 30$ for 1 unit only! It's a little bit too expensive...considering the PIC Price.

On the other way, Byonics (http://www.byonics.com/ --> see the tinytrak) doing the job with a PIC. I've just found interesting to try to make that myself!

PS: If someone have some information about FSK chip taht could be available at low cost, let me know...

thanks,
Martin