Hi,
I think that your maxvalue and minvalue should be the raw value from the adc ie. between 0 and 1023 and not the raw value times 64.

Otherwise this will not work:
Code:
dummy = (AdcResult - MinValue) * 64
You get a value between 0 and 1023 from the ADC. Then you subtract 2200 from that which will make it negative and you don't want that.

Try setting the max and min value to the raw reading from the ADC.

/Henrik Olsson