This isn't true. USB PD has both "data role swap" and "power role swap" commands, and they are independent from each other.
It even allows for things like a "fast role swap", where you can unplug the power source from a dock (so power now has to flow from laptop to dock, instead of dock to laptop) without any interruption of the data connection.
For example if you ask a USB-C power brick to let you swap to providing it power, it will reject that. Then some devices (like phones, tablets etc.) will only accept power when they're switched off, but will do either when they’re on. But some will happily let you switch to device mode and be a sink when they’re off, until the battery gets below a certain level and then they’ll only accept you providing it power. It all gets quite complex!
The company I work for makes devices that are always in device mode (called upstream facing port or UFP mode) but can provide power when they are plugged in themselves, so have to swap between source and sink. I’ve spent far too long debugging firmware issues with PD controllers because of this!
It sounded like the line you quote was expressing suprise that baseline USB power supply in USB-C - without implementing PD - can't do that. But apparently could with older USB OTG.
I remember using one to play Fire Power on the Amiga, my first network game.
Funny enough, if I plug the USB-C/A dongle on the end of the power bank and the cable into the MacBook, it also won't charge.
I also have a Philips One toothbrush with a USB-C charging input. Similarly, I can't charge it with a USB-C cable directly from my MacBook but have to use A in between (I unsuccessfully tried using either a thinner "lower speed" or a thicker "higher speed" USB-C cable). I'm assuming the toothbrush doesn't support PD, so then why can't it fall back to traditional charging with a C-to-C cable?
A C-to-C cable, OTOH, doesn't have this requirement, and if there's no PD negotiation, the MacBook is not required to provide power IIRC.
- with SuperSpeed implemented
- note that all components need to be compliant (macbook, cable, toothbrush)
That's a lot of ifs just to charge a toothbrush. I would be greatly surprised if someone actually did (yes, it might already be cheaper to source SuperSpeed components at scale; I don't yet find it likely though)
Because USB-C says that a power source cannot provide 5V onto Vbus until negotiation has happened to prevent both endpoints of the link "competing" for power which can have disastrous results - for USB-C devices, that is either two resistors on cc1/2 that is pretty dumb 5V, or it is actual bi-directional communication. Early USB-C devices, most infamously the Raspberry Pi 4, various vapes and likely your toothbrush managed to mess that up [1], although I recently came across a flashlight at Lidl which also has broken resistors.
Using an USB-C male to USB-A female adapter fixes this because the adapter has the two cc1/2 5K resistors correctly in place. The adapter can safely do that because - other than early USB 1 era hubs - 99.999% of USB-A devices with a separate power source have backfeed prevention, and so the source side will just provide 5V at either 100 mA or 500 mA cutoff.
More sophisticated power source devices will also try negotiation over D+/D- after the sink device has started to negotiate higher voltages using various proprietary schemes, there's controller chips available that speak everything from plain 5V@100mA bootstrap over 5V@500mA USB2 and proprietary schemes up to 20V@3A (and probably, given the newest USB-C PD specs, even higher), without even needing an external microcontroller (but of course, muxing the bus for everything up to USB4/TB should there be one). Absolutely wild.
[1] https://hackaday.com/2019/07/16/exploring-the-raspberry-pi-4...
They don't get the excuse of "early". The first macbook with USB-C came out four years before it.
I don't know nor understand why it doesn't work and if it's a bug in the power bank or the laptop
The one trick I've heard works (but haven't tried) is to "kick start" it by connecting two chargers, one with higher wattage and one with lower, then giving it a minute to begin charging, then disconnecting the higher-powered one. Apparently that's enough to get it past the initial issue and then it will continue charging (more slowly) from the lower wattage charger.
There was a firmware update a while back that was supposed to improve things, but it didn't change the behavior with my 27W charger.
It's too late to edit my original post :(
USB-C does support this. It's known as a DRP (Dual Role Port). USB PD can be used to signal switching between downstream and upstream facing ports depending on state of charge of the battery for instance. The problem is that many devices do not support this, and I strongly suspect your power bank is the issue here. iPhones and Apple stuff in general supports DRP renegotiation quite well. They tend to be USB-C compliant as much as possible, which can lead to issues with interfacing with 'USB-C' devices that are not actually properly compliant.
And there's seemingly no way to get the phone to not try to charge things regardless of what the other side thinks (and when plugging the laptop in, it starts to charge the phone).
The alternative would be using WiFi (in a very RF polluted space) or Bluetooth (horribly slow), versus USB-C where 5g via my phone in Bangkok can get 250mbit easily. Whereas my Android phone has options for 'data only' etc. without charging which seems like it's more of a UX 'Apple' thing than anything else.
Buy a Y-cable from Ali Express that has USB-C male to plug into the phone, and both USB-C female and USB-A female sockets. Plug keyboard into the USB-A and the charger into USB-C.
But it doesn't work, and I suspect it's a software limitation at least on my phone (Moto G Play 2023). If the charger is plugged in first, the phone will charge but not use the keyboard. If the keyboard is plugged in first, the phone will use it, but not charge. I think the wires are there to make it all work, but the phone's OS just doesn't support this scenario. Pity.
Needless to say documentation is nonexistent so I don't actually know what's in the cable. For all I know, the two female sockets are just connected in parallel.
If you are looking for a solution though (albiet a bit bit bulkier one) it's likely any of a number of "USB C hub" or "USB C dock" products would work there. Most have a USB-C port marked "PD-IN". Plug the hub into your phone, plug your power into the PD-IN, and use the USB-A/other ports to connect your other devices. Run you like $20 from the usual suspects.
Sadly, one limitation, at least on the Android device, is that you can't use it in landscape mode with a mouse. Well, you can, but the launcher only operates in portrait mode, as do a lot of apps. I don't want to change the launcher - elderly folks get very fixated on how their device is supposed to work. Anyway as soon as the phone switches to sideways-portrait mode, the mouse also does which is very disorienting.
I can't blame the USB-C people for not working on this case. It is a lot harder than it seems to make work, and of limited use. Just get a USB-C hub if you need this ability.
But this thing wants 1.5A at 5V. And doesn't do any power "negotiation" at all, as far as I can see. It happens to work because modern smartphone chargers can do 5V at 2A by default. But plug it into any older charger and the charger immediately shuts down due to overcurrent.
I have one of those USB passthrough voltage/current meter gadgets. Yes, it draws 1.5A. I guess what it should be doing is slow-charge unless it can negotiate for more power. It's a very decent flashlight otherwise.
Oh, it also has two USB-C sockets. A red one for charging, and a black one for using the flashlight's substantial battery as a power bank. I don't know what would happen if you plugged the charger into the wrong socket and don't have the courage to try.
USB-C does a bit of negation before putting our any significant amount of power. There's a "dumb mode" that just uses a pair of half-cent resistors and is fine for up to 3A at 5V, and then the "smart" PD (Power Delivery) mode that does a digital negotiation and can do much higher wattage.
All that is to say that if you plugged the black USB-C into a charging brick it'd probably just fail the negotiation and nothing bad would happen. Both sides would have to be violating the spec for it to be a real hazard.
Annoyingly, some really cheap devices skip out on even the dumb mode resistors to save a penny, and so even though they have USB-C ports, you have to charge them with USB-A to USB-C cables (because USB-A ports always provide power, no negotiation required.)
Those devices are where the cheap Y-cables come in handy, because they usually include the required resistors + give you a USB-A port.
American companies like Skullcandy do this too.
The smartphones should have proper USB-C port, I haven't heard of one with charging problems, and included USB-A cable cause cheap.
Using a device which is mostly lithium ion batteries as a weapon? Even scarier than you expect, if you puncture a battery
I've seen plenty of those devices, where you have a female USB-C socket to connect a charger to, a range of other female USB-C, USB-A and other ports for peripherals and a short cable with a male USB-C plug to connect to a laptop. If everything works, the dock will act as a power source for both the peripherals and the laptop, but will act like a hub on the data lines, with the laptop being the host.
I wonder if it would work just the same if you connected a phone instead of a laptop to the "host" cable.
I've connected my phone to the host cable of a dock before and everything worked. (I didn't try the HDMI output, but sound on the dock just worked)
Battery Charging 1.2:
> An Accessory Charger Adaptor (ACA) is an adaptor which allows a single USB port to be attached to both a charger and another device at the same time.
Figure 3-1 shows the various configurations covered. The third one indicates the intent of having an adapter with data pass through to an accessory while powering from a third port fed by an external USB supply.
These exist today as USB-C splitters.
https://vi.aliexpress.com/item/1005007015739540.html
which does claim to work with various smartphones. We'll see.
If I plug a NVMe drive into my iPhone, my phone will run out of battery so quickly so I have to use a hub and plug in my charger at the same time.
I had been designing a device that heavily relied on USB, as its primary goal was to be basically a USB switching station, where you plug your systems and USB into the device and then can swap around which USB is connected to any of the connected systems.
I started during the early USB3x days, and by the time i had a completed design, had to rip out and redo large chunks because the damn USB spec changed with all their 3.x super premium plus ultra speed bullshit. And then... fucking USB c. yes, you dont have to figure out which way the cable goes now, but hardware designers are suffering because of the shenanigans that is USB. My entire project was effectively scrapped because i didnt want to deal with the power draw bullshittery. Before PD it was easy enough for me to manage the power, but now, i need a whole load of supporting circuitry and have to touch datalines which my original goal was to avoid.
In short, i hate USB and its gone the way of the SCSI cable; getting more and more weird every year
Once I was charging my SteamDeck using a cable I thought was quality, and the darn connector bit felt alarmingly hot to the touch. Turns out the cable wasn't certified for PD applications and was better for 5V @ 4.5W...
Any cable not fulfilling these requirements isn't allowed to called a usb-c cable, though I'm sure certain foreign manufacturers don't care.
With all due respect, this is the way it should be. Hardware designers are inconvenienced so that millions of users don't have to be.
So they end up with millions of implementations that do not meet the specifications, and in undocumented, unpredictable ways.
With USB C, my eyes don't help at all with devices nor with cables. Is it a power input? A power output? Both? Does it support a display? Is it USB 2, 3, or none? I have no direct way of telling -- my eyes don't help, and nor do my other senses.
The current model displays active lines, but there's a Kickstarter for one that shows more information: https://www.kickstarter.com/projects/electr/ble-caberqu-a-di...
https://www.amazon.com/Treedix-Tester-Checker-Acrylic-Chargi...
Add to that a microcontroller, screen and software and the price doesn't look unreasonable to me, especially for a small project like this.
There are also cases where there can be active electronics in the cable where pins can seem disconnected by a continuity tester but they are actually connected to a chip inside the cable.
Also as an aside, it should be possible to just plug a cable in, and have your OS tell you what kind of cable it is and it's specs. The USB controller has access to this info but there is no standard way to pass it up to the OS like you have with other USB info. Apparently Chromebooks do have controllers which expose this so they can tell you when both the laptop and charger support faster charging but the cable is limited.
This is what I was expecting when you said acrylic case: https://www.raspberrypi.com/products/raspberry-pi-4-case/
"screenshots": https://kalleboo.com/microblog/posts/109391700632886806.html
HAHAHA! NAÏVE PERSON!
You couldn't watch Netflix on USB OTG. Because... because of... REASONS YOU STUPID PIRATE!!! OR FUTURE PIRATE!!! OR FUTURE WANNA BE PIRATE! YOURETOCLOOSSEETOBEEINGPIRATEYOUPIRATE!
____
disclaimer: I do not want to offend anyone. Above sentences are what I hear in my head when I see that my phone with USB OTG/USB-C is not showing the video on my tv or monitor, or even showing but only subtitles.
disclaimer 2: connecting screen using USB OTG was called MHL, not all devices had (has?) it
As far as connecting an external monitor, that’s a standard USB C alt mode that your phone doesn’t support.
https://www.benq.com/en-us/knowledge-center/knowledge/usb-c-...
My iPhone 16 can send video and power to my USB C portable monitor over one cord. It can only drive the monitor as far as power up to 50% brightness.
If I plug in a separate power supply to the second USB C port on my monitor I can run my monitor at full brightness and the monitor will charge my phone while my phone is sending it video.
Of course my laptop supports powering and video at full brightness over one USB-C port
This is totally the fault of your hardware for not supporting part of the USB C standard.
Even Google just started supporting it last year.
https://www.androidpolice.com/google-pixel-9-display-output/
My thinming is square. I still connect my monitors using SVGA and watch movies on them. Truly this sounds to really complicated that a phone which is indeed a computer cannot do computer things. My first android was closer to my Linux than every each version following. My colleague had SSH server on his Motorola phone. What I moan about is that limiting, strangling list of changes made to browsers and systems that is happening right now
I agree with that point, but I don't think that's what's happening here.
Go back a couple of years and you'll find tons of posts of people trying to get Netflix working on linux. People did find various workarounds of course, including really stupid things like changing the user agent of your browser, but it really wasn't working out of the box like it should.
So the problem really isn't that your pocket computer can't do computer things, but that HDCP is doing what it's designed to do, restrict people from using video streams in a way not envisioned by the designers. The fact that this is a (legally) legitimate use-case doesn't matter, it's just collateral damage.
That’s exactly what is happening. The newest Google Pixels phone that support DisplayPort alt-mode over USB C should work with the Netflix app.
You’re over indexing on Android being based on Linux
? I think you misunderstood something, but yes this works now also with usb-c alt modes on newer laptops on linux, hence the "go back a couple of years" part of my post.
An iPhone with USB C supports most of the standard protocols you would expect - video, Ethernet, audio, external storage (USB 2 speeds on non Pro models and 10Gbps on pro models), and wired keyboards and mice.
Can you run unmodified LibreOffice or Wine on it? I can on my Librem 5.
0. https://www.reddit.com/r/termux/comments/1e6ahlg/how_do_i_in...
1. Because I don't own x86-64 Android hardware, and it's usually pretty awful (Dell Revue).
By that definition, Windows is a Linux, too (with WSLv1).
On the other hand, if you're a syscall purists and are particular about the dependency on virtualization microprocessor extensions (or the lack thereof), then the stack requiring a hypervisor to run a guest isn't equivalent to the OS it's hosting.
Bottom line is: if you have a shell access/ a terminal emulator on stock Android, you can configure it to run a desktop Linux using the kernel loaded on the device without installing am emulator or hypervisor. To me, this is materially different to WSL or ChromeOS' crostini.
Can I say I'm fluent in Tagalog with the help of my "English Subsystem for Tagalog v1" (aka a hired translator)?
1. https://learn.microsoft.com/en-us/shows/seth-juarez/windows-...
WSL1 does translate many syscalls. Others it implements itself. It does not virtualize or hypervize. It does not emulate linux. WSL2 emulates/virtualizes/hypervizes, but WSL1 and WSL2 use completely different technology stacks at their core.
The translator is running inside the kernel as a driver.
If your company hires someone to speak tagalog, they become part of the company, and your company now speaks tagalog.
Windows supports linux binaries in the same way that it supports flash drives.
I don't do Netflix, so I don't care. Youtube works fine.
I also have some peripheral devices with a captive micro-B cable (with ID pin configured like like micro-A) that were specifically intended to be used with OTG compatible phones.
I still remember getting so close with the Google Nexus 4 to being able to connect an SD card reader. It supported OTG, but did not have the required charge pump to supply 5V of VBUS. (Supposedly you could hack together something using a 9V battery, some resistors, and a kernel patch, but that was a bit more than I was willing to risk for the convenience.)
Finally, the Nexus 7 and Nexus 5 supported it out of the box, and while Android didn't offer a FAT32 implementation back then, there was (is?) a USB host API which let apps supply that instead, and I think somebody actually ended up implementing FAT32 in userspace to make it all work!
I should make a custom Linux image for the Pi4+ (the whole process is probably too slow without USB3) and some automation (Jenkins?) to do this, I'm sure there's photographers who'd find it useful.
Personally, these days I have less of a need for that kind of thing, given that I can just plug the camera or disk into my phone directly (I suspect a powered USB hub and plugging in both at the same time might even work as well?), but I vaguely recall dedicated "copy everything off this card onto a hard drive" devices being sold, and I don't doubt that some photographers still use these in their workflow.
My Sony can do MSC mode when connected to the PC. I haven't tested but I assume it would do the same when connected to a phone.
Was super cool reading the OP article and finally learning how the thing actually worked with the 5th pin.
Oh, and cameras still take better photos than phones, and it's weird that you would think they don't - they're devices that cost more than phones, designed specifically to take good photos.
I also had the HTC Thunderbolt and remember getting ~75Mbps initially. My wife's family lived way out in the countryside in Illinois and had something like 2Mbps DSL internet. But on one visit, I realized that if I walked down the road a short distance to the top of a hill where I had line of sight to what turned out to be a Verizon tower, I could still get ~75Mbps! I took advantage of that once or twice to get things downloaded in a more reasonable amount of time.
The parallel port was a nice way to have GPIOs in a computer back then. A bit like the GPIOs in today's SBCs, but more rudimentary.
Once case for me is a post someone wrote in the late 90's that was concerned about parallel ports going away and everything being subsumed by USB et al, cutting off hobbyists and experimenters. It made a lot of sense at the time, and I've thought about this many times since.
Obviously USB has been widely embraced and is highly successful for experimenters, hackers, etc. Whatever friction it causes is so vanishingly small that few people today even suspect that there might be any reason for concern.
But yeah, I get what you're saying: built-in GPIOs on every box by default used to be a thing, and it would be cool to have even now.