Use an operational amplifier to sum the incoming signal with +1 volt. Choose the resistor values to give a gain of 0.37 on the incoming signals. You don't need the voltage divider. Also the fixed voltage does not need to be +1 volt, although it does make the resistor value calculations slightly simpler. Regards Chris Carr ----- Original Message ----- From: "Dennis Oliver" To: Sent: Friday, August 17, 2001 6:33 PM Subject: [PIC]: I am trying to figure out a way to measure a DC voltage that ranges from -0.9V to +12.5V. I ideally would like to just add 1V to the signal, and then use a voltage divider to get it to the 0 to +5V range of a PIC. How do I condition the signal??? -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.