A frequent contributor to the hacker neighborhood, [stacksmashing] has ready a wonderful tutorial video on reverse engineering Apple’s Lighting connector proprietary protocol. The video begins by displaying acquire bodily entry to the indicators and hooking them as much as a logic analyzer. He then notes that the handshaking makes use of solely a single sign and proposes that Apple isn’t going to re-invent the wheel (maybe a dangerous assumption). Utilizing a ChatGPT search, compulsory as of late, we be taught that Dallas Semiconductor / Microchip 1-wire might be the protocol employed.

Which embedded single-wire busses exist that encode bits with completely different lengths of high and low indicators?

On the fundamental degree, 1-wire and protocols like Texas Devices SDQ function in an identical method. It seems that [stacksmashing] already wrote a SDQ analyzer module for the Saleae logic analyzer. Aided by this device, he digs deeper and learns extra in regards to the sorts of messages and their contents. For instance, upon being plugged in, the host system queries the accent’s serial quantity, producer, mannequin quantity, and product description. Lastly, he introduces the CRC reverse engineering device reveng to find out which CRC polynomial and algorithm the protocol makes use of to border every packet.

Even in case you have no real interest in Lightning cables, this video is a superb tutorial on the forms of issues you must do in an effort to make sense of an unknown communications protocol. Collect what data you may, make some educated guesses, observe the indicators, revise your guesses, and repeat. Partially two, [stacksmashing] will present construct a home made iPhone JTAG cable.

We wrote in additional element about cracking the Lightning interface again in 2015. The Lightning interface could have been a very good resolution in its day, foreshadowing a few of the options we now have in USB-C. However its proprietary and closed nature meant it wasn’t used exterior of the Apple ecosystem. With the proliferation and capabilities of USB-C, to not point out varied legislative edicts, Lightning’s days appear numbered. Is the business lastly selecting one interface? Tell us your ideas within the feedback beneath.