That would be another great use for the tones, choosing which remote node you would want to connect to. How well does the DSP cut out squelch tails? If I wanted to use the COR I supposed it would be just as easy to use a transistor to get the ground. Should I be worried about someone accidentally hitting that volume down button and sending 3.3v back to the radio? I don't know if there will be a difference, but this time I am making all of the circuits external. I'm using a little radio shack project board instead of trying to cram it all in the usb housing. I left the audio output jack on the board for monitoring/testing, but I removed the mic connector to route the wires through that hole. The usb adapter I got from dealextreme had surface mount jacks, so it was really easy to remove and solder wires to. Jeff WQEX694 KB1SPH
According to the docs...if you are using discriminator you do not need to hook up COR.. if you DO want to use COR...it requires a pull to ground as you noted.. by default. The pull can either be COR or NOT COR ..I think it was a command in the usb dongle configs.
I would let the dsp do the work... you only need the discriminator audio that way..
The notes look like it can handle more than one tone... but that is a question I am curious about too.... Especially if the tone used can cause a routing change on the internet..like the tone can trigger an automatic route selection.
Doug KD8B