10/7/2023 0 Comments Apple lightning cable suppliers![]() Some requests do not need a response though:ĭx configuration when ID is found on ID1 Dx HiFive replied! And if you scroll further you'll see a lot of other request/response pairs: I'll use Apple's original Lightning to USB cable:Īnd here is what appears on IDBUS after a 0x74 request: Let's connect some accessory to our setup and see what happens. 0x1f - CRC8 of both the request type byte and the whole data (polynomial - 0x31, initial value - 0xff).Always even for request, always odd for response (request type + 1) Now let's examine the data stage on the example above - 0x74 0x00 0x02 0x1f: If it's not issued in this time interval, Tristar will try to poll another ID line Tristar will wait for around 2.2 ms for a reply. Then a slave must send a reply (after at least a 2.5 us delay - see the table). When a data stage is over, a host sends another BREAK. Please pay attention to the fact that last (8th) bit of a byte has longer Recovery Stage. Using the above table we can now build a simple decoder of the protocol:Īs you can see, the first word a host sends is BREAK - when Tristar wants to send a new request, it always starts with it. * - STOP is used when it's a last bit in a byte Here is a table of known word types with their time intervals for both stages we discussed above (all units are in microseconds): Recovery Stage - time interval which is apparently required for processing the Meaningful Stage on recieving side and/or preparing the next word on sending stage.Meaningful Stage - time interval taken by this stage defines meaning of a word. ![]() So basically a word is a combination of fall- rise- fall: But how to interpret it? How to decode it? Let's virtually split it to almost the least least significant parts - to something that I call words: What happens next is far more interesting: Meanwhile let's examine what exactly happens while polling:įirst, we can see a long interval (~1.1 milliseconds) when the level is just high and nothing else is happening:Īpparently that time is used to charge internal HiFive's capacitor - the energy from it will be then used to power-up its internal logic chips At some point the device will grow tired of this endless stream of failures and stop it. But since we didn't connect any accessory, the polling obviously fails. You'll see something like this:Īs you can see, Tristar polls each ID line by rotation - one after another. Right after that start sampling (any rate from 2 MHz and up should be fine). Take a logic analyzer, a Lightning male-to-female passthrough breakout board, some accessory (normal Lightning to USB cable would fit just fine) and of course some device with Lightning portįirst connect logic analyzer's channels to both ID lines of the breakout (pins 4 and 8) and connect the breakout to the device, but do not connect the accessory just yet: Let's sniff the negotiations between Tristar and HiFive. NXP CBTL1612Ax - Hydra used since iPhone 8/X and apparently everything else that supports wireless charging ( x - number of generation)įrom now on, I'll only use the term Tristar, but keep in mind that it will also mean Hydra as well, as they are very similar in the most of aspects that are gonna be covered in this text.There're multiple generations of this one ( x - number of generation) NXP CBTL1610Ax - second-gen Tristar used since iPhone 5C/5S and apparently everything else that doesn't support wireless charging.NXP CBTL1609A1 - mysterious first-gen Tristar used in iPod nano 7 - source.NXP CBTL1608A1 - first-gen Tristar used in iPhone 5 and iPod touch 5.TI THS7383 - first-gen Tristar used in iPad mini 1 and iPad 4.There're 5 major Tristar/Hydra variants known to me: The most significant change appears to be a support of wireless charging, but that's to be verified: Hydra - is the new variant of Tristar used since iPhone 8/X. Basically, it's a MUX:Īmong many other things, its main purpose is to communicate with Lightning male connector once one was connected - detect orientation and detect Accessory ID and route internal interfaces like USB, UART and SWD accordingly Tristar - is the integrated circuit embedded in every device shipped with Lightning female port.
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