General > General Technical Chat
The EU is enforcing USB-C on portable devices
SilverSolder:
None of the USB-C devices near me here (laptop, phone) show any symbols at all next to their ports... so, it is a mystery what they actually support.
The USB-C standards committee has dropped a clanger here, for sure - ruining the simple elegance of USB.
SiliconWizard:
Yep. While a single USB-C connector on a mobile phone, and even on a tablet, has about 100% probability of serving as a charging port (especially if there's no other charging port available), the situation becomes blurry on laptops, or mobile devices that would have several USB-C ports.
I recently had a colleague wonder whether they could charge their laptop through one of the USB-C ports (the laptop has otherwise a dedicated barrel jack charging port.) Turns out it was undocumented for this particular model, while other models of the same brand either officially supported it or officially did not. He bluntly tried on one of the USB-C ports, and it... worked. Who knows why it was not documented but still implemented. Maybe tests had just shown issues, or maybe it didn't pass EMC, or maybe just for marketing reasons... Either way, there is no indication on the port itself whatsoever whether it will support charging or not.
Berni:
--- Quote from: SiliconWizard on June 28, 2022, 04:58:22 pm ---As far as I've seen, none of the "conventional" markings can indicate whether a given USB-C port supports *charging the device* through it. Please tell me that I missed it, though.
--- End quote ---
Yep i could also not figure out what port is for charging. Or can that be done by any of the ports? Or is the battery symbol actually bidirectional. So fast charging output but also fast charging input.
Another thing that i found a bit confusing by the standard is how Thunderbolt support is marked. This shows the Thunderbolt capable port having a lightning bolt drawn next to it and no USB symbol at all, even tho it actually includes USB 2.0 capability (and all other examples have the USB logo in it somewhere). Then in a confusing way a fast charging USB port is shown to have a USB logo and a different lightning bolt icon on it. To make things even more confusing Thunderbolt capable ports also include DisplayPort capability, yet that table does not show a DP logo next to it.
Then making things worse there is no mention of the HDMI alternate mode (that USB-C can support by the spec). Given that the new DisplayPort specs do include a special mode that allows HDMI emulation on passive adapter cables, so one would expect the DP symbol means USB-C to HDMI cables will work. Yet this does not seam to be the case. Acording to wikipedia active adapters are required for this. Instead to get a passive HDMI cable your device needs to actually support the HDMI mode specificaly.
This thing is a mess :scared:
tszaboo:
--- Quote from: Berni on June 28, 2022, 06:00:02 pm ---
--- Quote from: SiliconWizard on June 28, 2022, 04:58:22 pm ---As far as I've seen, none of the "conventional" markings can indicate whether a given USB-C port supports *charging the device* through it. Please tell me that I missed it, though.
--- End quote ---
Yep i could also not figure out what port is for charging. Or can that be done by any of the ports?
--- End quote ---
Yes, this is a mystery. Quite a pickle.
Maybe vote with your wallet, and only buy devices that mark the port? Or maybe the politicians can mandate the markings, but that would limit innovation. What if a better symbol is invented?
eugene:
It wouldn't bother me if the politicians mandated decent documentation.
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