ADC values negative in range of (127 to 255)

[mbogucki]

Hi All,

We've been attempting to solve a "simple" mystery. In the process of creating a simple datalogger, we've used the ex_admm.c example as our base code.

When using the example outright, everything looks good, but the output is in hex. We've changed the code from:

printf("\n\rMin: %2X Max: %2X\r\n",min,max);

to
printf("\n\rMin: %2d Max: %2d\r\n",min,max);

in order to see everything in decimal.

When running, the output is fine when our range is from 0 to 127, but when we go beyond this, the values are now -127 -- 0...

Can anyone shed some light on this mystery?

In terms of hardware, we are using a pic 16f876. and our compiler is version

PCM compiler version 3.163


Thank you very much for your time and support.

--Mike Bogucki

[PCM programmer]

In CCS, to display unsigned 8-bit values with printf(), you use: "%u"

To display unsigned 16-bit or 32-bit values, you use: "%lu"

[mbogucki]

Hi PCM Programmer,

Sorry for the long delayed response...

Thank you very much for the suggested solution. It worked like a charm!!!

--Mike