MCHIP has an application note for solar panel MPPT algorithms: http://ww1.microchip.com/downloads/en/AppNotes/00001521A.pdf Not sure how good it is. ~ Bob Ammerman RAm Systems --=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 .