![]() ![]() 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.
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