Don Hyde wrote:
> <snipped>
> You are, of course, configuring your I/O port for input, so it is in the
> high-impedence state, and negligible current is actually flowing in or out
> of the PIC.  In a very power-critical situation (i.e. sleeping for an
> extended period), you will use less current when the switch is open, and not
> drawing any current through the resistor.

One decent solution:  Use another port pin on the other end of the
pullups;  That way you do need a little more code (pull that port pin
high right before you read the switches, tristate it right afterwards),
makes debugging a little harder but does save power.

(You cannot always choose which switch state's going to be more likely,
for example a "readouts in degrees F or degrees C" select switch, you
CAN save power though.  If you have something else you're turning on
only when awake, by all means use that pin or have it drive a buffer to
drive the pullups!)

  Mark

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