Small pin-count device for generating output frequencies when triggered

[Dave]

Jim, I have attached a small program I worte a few years back for a 10F222 processor. It was for generating 2 different tones simulating a CW message for amatuer radio to be used for ID or Fox hunting purposes. It would key the radio push to talk circuit, wait 250 Milliseconds and then send the message. It would then go into a sort of sleep mode for about 6 minutes. During the sleep time it awakes approx. every 2.5 seconds and reads a port pin to see if is being commanded to transmit before the timeout period. Use it as a starting point for your project. I don't see why you couldn't use the A/D to set the tone frequency.