Mark, I got some 12V alerts during the last 3 days. Checking the 12V reading after the alerts showed normal level, so I'm trying to figure out if they were false alerts. Last alert was about 2 hours ago, alerting about 11.0 V -- my check only a few minutes later showed 12.1 V again... I've read into the PIC18 doc on the A/D conversion (chapter 19). AFAIS inputs_voltage() differs from the example in two ways: 1) the example does not turn off the converter after reading the result (but I understand the ADRES register should keep the result) 2) the example step 3 says "wait for acquisition time if required", it seems our function currently does not wait. "To determine acquisition time, see Section 19.1 “A/D Acquisition Requirements”. After this acquisition time has elapsed, the A/D conversion can be started." Section 19.1 contains an equation based on hardware parameters I don't know. Can you please have a look and tell if missing that wait time could lead to false measurements? Thanks! Michael -- Michael Balzer * Paradestr. 8 * D-42107 Wuppertal Fon 0202 / 272 2201 * Handy 0176 / 206 989 26