What would cause sharp positive going "hair" on an ADC input? The ADC is reading ground immediately before, so the sample/hold cap should= be discharged, yet every time I sample I see this sharp positive spike on = the ADC input pin. I don't believe there is anything else happening with that pin, and it's al= ways an ADC input. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .