Quote:
Originally Posted by Al Skierkiewicz
If you are going to the analog board, it does not have pull up resistors so you have to use the SPDT to switch between +5 and zero volts. If you use a digital input, the pullup would allow you to simply open or close a connection to the common to give two states.
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Sorry, Al, but I have to disagree. If you put a 10k pullup resistor between the analog signal and +5 power pins, a simple SPST switch between signal and ground will give the desired results. The schematic Darren posted is exactly how I would do it.