Which Arduino emulators can also emulate a MicroSD card and reader? (I've tried 123D, but I can't figure out how to use it for that, because the FAQs are not helpful enough). I need to read and write to an SD card.
I would recommend testing with actual hardware.
Those Arduino simulators have a rather dismal reputation.
You have to test with real hardware because whatever you buy won't ever quite match the one you simulated. I would skip the simulation test. It can only cost you a few bucks even if it turns out that the hardware is useless for your application and must be thrown in the junk box.