• Paulemeister@feddit.de
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    1 year ago

    The lighting connector only features two differential pairs. But as I understand it, USB 2.0 can only use one of those. The next upgrade would be USB 3.0 (Officially USB 3.2 Gen 1x1, but let’s not get into that) which uses 2 differential pairs but also keeps the USB 2.0 connections untouched, so it needs 3 pairs.

    Maybe you could cheat and get a non compliant USB 3.0 device connected via lighting to USB A, using one of the pairs for setup, then going into SuperSpeed mode and using the two pairs in full duplex (both ways at the same time). Maybe that’s what the Lightning to USB3 Camera Adapter does.

    USB-C has the capacity for 4 shielded differential pairs, the 2.0 comparability pair and two pins for alternate mode, which makes it not only capable of, but necessary for USB 3.2 (USB 3.2 Gen 2x2 and USB 3.2 Gen 1x2) and upwards. (Don’t ask me about USB4 (not named USB 4 for some reason))

    Lightning has some other quirks like being able to carry UART, JTAG and other Debugging stuff, which is communicated with a chip inside the phone/tablet etc. But since that’s closed source, it’s only been reverse engineered