Answer to: What kind of USB controller does the iPhone 4 have?Yes, there is USB onboard, since the very first iPhone. There's also been Firewire in the past. Pinout image Fairly unlikely to be USB3, though, I'd guess it's USB2. However, it's certain that Apple have made it very difficult to access. Currently with jailbreaking and the iPad camera connection kit (an adapter which makes the USB pins of the dock connector available via a USB socket) you can only get a USB keyboard to work, you can't use mass storage devices or external devices such as MIDI keyboards or audio interfaces. It's a shame, really, the USB controller is in there! You're just not allowed to use it. Perhaps in a future iOS update it will be made available.