At 01:00 AM 4/6/2004 -0400, you wrote:
>When a PIC input is configured as an analog input, then the digital input
>buffer is disconnected from the pin and held at ground. This will result in
>the digital input reading zero, no matter what voltage is on the pin, and it
>also avoids the issue of excessive (more than data sheet) current draw
>caused by 'shoot through' in the digital input buffer.
>
>OTOH, if you configure a pin to be both an AD input and a digital output,
>then the AD will convert the digital output voltage. This could be a useful
>way of checking for shorts or other problems on the pin.

Cool. So, if I look at PIC16F87XA, if the output pin is sourcing current
and we measure 4V (with 5V Vdd), we know the current (within 3 sigmas) is
between about 10mA and 17mA (13mA typ.)

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

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