In reply to:


How about allowing for the +12 volts to come down the Serial cable into the DB9 connector [with maybe a simple on/off jumper to allow this option to be disabled on the PCB], as an easy way of getting the necessary voltage into the PCB to run it.


That is a really cool idea. Didn't even think of that. I'm assuming that the +12V uses the GND pin on the connector as well, then?
Would there be a problem (I can't see any off-hand) if the GND on the serial is always connected to the power ground?
(i.e. I have it at home, with a 12V adapter plugged into it. The DTR line is disconnected from the external power via the jumper, but the GND would still be connected. (Just seeing if I need two jumpers, for the GND and +12V, or one would do.)

<Evil Laugh> I like this... </Evil Laugh>
Me.
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Mike 'Fox' Morrey 128BPM@124MPH. Love it! 2002 BRG Mini Cooper