Cannot charge an iPhone 16 using two USB-C breakout boards

[chronicintransigence]

I have a project where I am using two USB-C horizontal breakouts with all 6 wires connected to both breakouts.

When I connect a USB-C cable between a power charger and my dev board and a 2nd USB-C cable to my iPhone SE (using a USB-C to Lightning adapter), I can charge my phone.

However when I try to connect my iPhone 16 without the Lightning adapter, it won’t charge. It will charge if I unplug the iPhone 16 from the dev board and plug in a MagSafe charger pad, the iPhone 16 will charge from that.

Has anyone come across this before?

[TS-Russell]

It sounds like the adapters have an internal IC or something that negotiates with the Apple device and needs it there to function normally

[chronicintransigence]

I ordered another USB-C horizontal breakout and after some more experimenting, I ultimately found that if you remove the two 5.1K resistors on the CC1 and CC2 pins, it will charge the iPhone 16.

I ordered a couple more breakout boards for USB ports from Sparkfun–one was a USB Type A female and I verified that if you plug a USB Type A to USB-C cable, that it will charge the iPhone 16.

[TS-Russell]

Awesome! Good job