michael brown wrote: > That's pretty neat, I'll have to try that. I'm guessing that the > advantage is reduced current consumption and the fact that the > comparator is being operated at it's most accurate point. Does that > sound right? Yes to reduced current consumption, although I still show a 10K pot, which will consume 0.5 mA all by itself. It's important that the source impedance be low with respect to the wiper series resistor, or you'll get some nonlinearities. You could go with a higher-value pot and correct the nonlinearities in software if they get too large, since they're quite predicatable. It isn't so much that the comparator is operating at its "most accurate" point, but simply that it's operating at a single point. This eliminates all common-mode range issues. -- Dave Tweed -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body