While I COMPLETELY agree on the importance of not connecting mains voltage to your chest, there's at least one other way to safely do this without the opto isolation: Hook it to a laptop that is _not plugged into mains_. -Denny --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .