Thanks a lot, for the info. I think I'll try the LM324 if I can get a sample of it (No radio shack here in the UK!) . 3.5V should be OK for testing if things are working, the 10bit A/D is not enough anyway. I'm planning to get a 16bit A/D for it eventually.
Perhaps I should start a new thread for Frequently-Used A2Ds. I've got a 16bit AD7792, which works great but is too complicated to interface with. Anyone know a simple to use >16bit A/D that comes in a convenient DIP package?
-Z-