Using PIC as a Low Voltage Meter, need help

[falingtrea]

One thing you can do is to take away the resistor network on your analog inputs and just put a 1k in place of the 100k(for isolation and input protection). That resistor network is scaling a 0-70v input to a 0-5v in to the PIC.

Then connect a 2 volt source to AN3 to serve as the high voltage ref. To do this you need to set register bits PCFG3-0 to '0001'. This changes the range of the ADC to 0-2V, instaed of 0-5v. You could use a simple resistor divider like 3k/2k or a precision voltage reference like a LMV431 or even a zener diode.

[doable]

Thanks Tim for the info, i will try that and let you know how it worked.