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by KittenPassingBy 1009 days ago
I have devices that only works with Usb a to c cables. I also have devices that doesn’t accept the same. ditto for e-marked cables, and passive charging cables. I now need to get a usb c cable tester and label each cable and device.
2 comments
alistairSH 1009 days ago
Same. I have a few “USB-C” devices they inexplicably won’t charge from some (mostly Apple) USB-C chargers. But they work fine with some other USB-C chargers and all USB-A chargers with an A-C cord.

But, with these phones, I can at least get rid of the dozens of Lightning cables I’ve accumulated. And only a few of my devices are still USB-A, so I imagine I’ll be all C soon enough (probably just in time for USB-D or something else).

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tpmoney 1009 days ago
USB C devices are supposed to have resistors on the CC pins to help negotiate power delivery with the port supplying power and to allow detection of pin orientation[1]. But to save a few pennies (or because no one read the USB C specs), many cheap devices don't have these resistors and USB-C chargers that implement PD are almost certainly configured to not supply any voltage at the VBUS pins until a connection is actually detected. As a result these devices won't charge from a spec compliant USB C charger. Cheap chargers on the other hand may be nothing more than a basic 5V 1A USB A charger with a C port instead and happily supply power on the pins regardless of the CC pin status. Likewise A-to-C cables would do the same thing, since A chargers just supply 5V continuously without any negotiation.

[1]:https://ww1.microchip.com/downloads/en/AppNotes/00001914B.pd...

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alistairSH 1009 days ago
Yeah, but some of these aren't "cheap" devices (Wahoo fitness devices have this flaw). Wahoo actually calls out Apple chargers in their doc, which is super annoying because it's NOT an Apple problem, it's shit design/penny-pinching from Wahoo.

And there are USB-C chargers (provided with Google phones and Belkin USB-C car chargers) that will charge the devices. So, I guess they're ignoring the lack of negotiation and just providing 5v? No idea.

So, consumers are left guessing what will work or won't. And carrying at least two chargers (one "dumb" and one "smart/PD").

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faeriechangling 1005 days ago
I don't mind people implementing things in this way to save money.

I have a problem with them advertising it as "USB-C" and USB-IF doing nothing to stop this false advertising.

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faeriechangling 1009 days ago
Yeah I'm aware of this issue, and specifically check for c-to-c compatibility, this falls under the category of "flawed implementations" because these devices are NOT to spec.

It's common for rechargeable lights to not support c-to-c cables and require a usb a to usb c cable.

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