Chaipi, Look in the PICList archive in the month of March and around the last week of th e month. I remember their being a discussion similar to this. The subject was "D riving/reading +/- 10V serial lines". I hope this was of some help. Best regards, Steven ************************************************* Steven Kosmerchock Enginering Technician CELWAVE Phoenix Arizona USA email: steve.kosmerchock@celwave.com ************************************************* www.geocities.com/researchtriangle/lab/6584 ************************************************* ---- PICLIST(a)MITVMA.MIT.EDU's Message ---- Hello PicList members, I need to build a device that would be able to measure an analog signal that range from -10V to +10V. Can anyone please suggest a circuit that will enable a PIC 16C77 to sample this voltage ? Thanks Chaipi \\\|/// \\ ~ ~ // ( @ @ ) ----------------------------oOOo-(_)-oOOo----------------------------------- ! ! ! Chaipi Wijnbergen ! ! Electronics/Computer Eng. M.Sc. Tel : +972-8-9343079 ! ! Optical Imaging Laboratory Fax : +972-8-9344129 ! ! Brain Research Center Email: chaipi@tohu0.weizmann.ac.il ! ! Weizmann Institute of Science WWW : http://www.weizmann.ac.il/~chaipi ! ! Rehovot 76100 ISRAEL ! ! ! ------------------------------------Oooo.----------------------------------- .oooO ( ) ( ) ) / \ ( (_/ \_)