The Apple C-to-Lightning cable appears to have a firmware issue causing it to fail on compliant #USB #TypeC PD sources. It will not charge (or be recognized on) an iPad Mini 2 Retina/iPhone 6/6 Plus. (Edit: This is a result of the charger! The cable works like a C-to-LegacyA + A-to-Lightning put together. Other legacy microUSB devices like a Nexus 5 would also be affected.)

(Edit: Benson has worked with Apple's engineers, and discovered this is a result of Apple following the spec to the letter. The PD chip in the cables does not interface with the USB data lines, so the iPad only draws 100mA as if it was plugged into a 5v source with no host enumeration! Chargers with sorted D+/D- lines are not victim to this. Thanks to him for this excellent debugging!)

I posit the Apple C-to-Lightning cable either (a) has a PD controller firmware defect that causes it to freak out and enter isolation-mode if it sees PD signaling it doesn't agree with -- ignoring even the basic CC Type-C resistor current advertisement, or (b) this is a "safety feature" by Apple intended to interdict bad chargers, that is overreaching its mark and effectively functioning as "charger DRM".

This is also a partial followup to the post about loaned samples. Since most of these chargers are blatantly noncompliant, I may not bother to do thorough individual posts.

I consider (b) as maligned. The possibility exists Apple is doing something very fancy, like verifying eye-diagram plots, which I lack the tooling to do. However, since dangerously-noncomplaint chargers are functioning with the cable, whereas compliant ones are not, it has already failed at that task.

To wit, the noncompliant (some dangerously so) RavPower 36W Dual ("30W"-PD), Tenswall 39W 3-port ("30W"-PD), and Verizon 24W ("24W"-PD) all function with the Apple C-to-Lightning cable.

This strongly leads me to believe it is (a) a flaw with the Apple-designed PowerDelivery controller chip embedded within the cable. Plain jane "dumb" Type-C resistor-based current advertisement chargers like the Google 22.5W work just fine. The compliant USB-PD chargers I analyzed all use resistors as a fallback. And are indeed supplying switched VBUS 5V@3A to the Lightning cable. Yet the iPad, etc. do not receive any of it.

To wit, the Anker PowerPort+ ("45W"-PD), Plugable CA1 ("60W"-PD rear port), and Dodocool ("30W"-PD) are not recognized by the Apple C-to-Lightning cable.

I welcome any comments or criticisms, as I have yet to identify the exact cause. This is a very significant issue since the ramifications are incredibly widespread. All C-to-Lightning cables would be affected, and there is no individual serialization to identify which ones. Plus, this is quite an expensive/rare Apple cable: I paid around $30 after tax for one in-person at the Palo Alto Apple Store.

Unless Apple can issue a firmware update, which is extremely remote -- Apple did so only once for their USB-C AV Multiport adapters, and ONLY for users owning a Mac running OS X El Capitan+ -- this cable is effectively DRM-locked to Apple chargers only. Not good.

[Plus] Analyses Apple C-to-Lightning Fail
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