Hi: This might explain it (uses a 16F72): https://patents.google.com/patent/US20120004788A1/en --=20 Have Fun, Brooke Clarke https://www.PRC68.com https://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by = how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. --=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 .