to simulaye on priteus you first have to verify that all the devices you need ARE simulated in proteus (not just in the library but also emulated ...)
and then I had problems with interrupts. proteus simulated the whole thing right, but hardware was not responding at all.
when doing the same program without interrupts, everything worked like a charm.
also I tried to simulate some esr meters and I never get exact result : proteus was not giving the right (if any) result, as the hardware was right.