100mAmp current reading using arduino DUe

Hi,

I am using a Arduino Due for simple ADC reading .
The basic concept is Controller has to read voltage of -10v to +10 input ,as of now I am Using an OPAMP to convert 0 to to 10V to 3.3v volt .
But I Don’t Know what to do with Negative Polarity and how to read it? this my first question …

and second thing i need to read current upto +/- 100mAMP using controller adc as feedback input.
Is it possible to read 100mAmp using arduino Due ??, Because i found maximum limit is 20mAmp .

sanjukumar: as of now I am Using an OPAMP to convert 0 to to 10V to 3.3v volt .

A 3-resistor voltage divider is normally used for that. One resistor from source voltage to analogue pin, one from pin to 3.3volt, and one from pin to ground. They must be calculated so +10volt produces 3.3volt, 0volt is 1.65volt, and -10volt is 0volt on the pin.

Does that 100mA come from a sensor? Please provide more details. Leo..

Not exactly sensor, my analog circuit output is +100 to -100mAmp and ,i need to read it from arduino due...