[MPaulHolmes]

Yes, it sure did. I read through the PDF you posted, and see what you mean about the sin and cos envelope. I'm not sure of how to extract the peaks. I was reading up on that, and it seems non-trivial. I think that resolver to encoder chip sounds like a good idea. The board could be really little and cheap. I would very much appreciate borrowing one of those MGRs. It wouldn't need to be this week or next week, as I would have to make a board to deal with the resolver issue. Can you calculate what shipping would be?

OK! I searched for the resolver to encoder chip, and I can't find your link or p/n anywhere. Could you repost it?

edit: I found an envelope detector which seems simple. It involves a capacitor though. Care would have to be taken so that it doesn't cause too much lag in the detection.

edit again: It could be made to work, but the chip would be better.