[HN Gopher] USB On-The-Go
___________________________________________________________________
USB On-The-Go
Author : jnord
Score : 151 points
Date : 2025-01-03 12:42 UTC (4 days ago)
(HTM) web link (computer.rip)
(TXT) w3m dump (computer.rip)
| crote wrote:
| > Application notes from several USB controller vendors explain
| that, oddly enough, the only way to perform role reversal with
| USB-C is to implement USB Power Delivery (PD) and use the PD
| negotiation protocol to change the source of power. In other
| words, while OTG allows reversing host and device roles
| independently of the bus power source, USB-C does not. The end
| supplying power is always the host end.
|
| 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.
| stephen_g wrote:
| Yes, the article kind of describes the default behaviour, but
| after the initial source/sink selection one end or the other
| can then independently request power role swaps and data role
| swaps, which the other end can either accept or reject.
|
| 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!
| nfriedly wrote:
| That reminds me of a while back, my phone battery was getting
| really low, like 1%. I grabbed a power bank and connected it,
| USB-C to USB-C, and for whatever reason, the two devices
| decided that the phone should be charging the power bank
| instead of vice-versa. Then the phone died a few seconds
| later. (Then the powerbank started charging the phone!)
| smallmancontrov wrote:
| With apologies to stephen_g, who I'm sure writes excellent
| firmware, this is the quality of decision making I would
| expect from median firmware.
| oez wrote:
| Aren't you agreeing with TFA then?
| dec0dedab0de wrote:
| It sounds like you're talking about protocol, and the article
| is talking about implementations.
| danhor wrote:
| Every USB-C docking station that exposes USB ports while also
| supplying the attached computer with power uses this feature,
| letting the computer act as a host and the docking station as
| the power source
| majormajor wrote:
| My impression from the article is that what you're saying is in
| line with it: if you implement PD, you can do either.
|
| 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.
| KingOfCoders wrote:
| "this was referred to as a null modem cable"
|
| I remember using one to play Fire Power on the Amiga, my first
| network game.
| nimish wrote:
| Null modem is also an excellent name for anything vaguely
| cyberpunk
| treve wrote:
| Warcraft 1 also supported this!
| thomas-st wrote:
| I have a power bank that is PD capable, but I cannot charge it
| from my MacBook even if the MacBook is plugged in to power. I get
| around it by using a USB-C/A dongle and corresponding USB-C/A
| cable. Presumably this "downgrades" the connection and since the
| MacBook doesn't support traditional USB charging it has to charge
| the power bank. Does USB-C not have a way to indicate that a
| potential power source is a battery so that the MacBook can
| charge it if it's plugged in to power, and reverse roles
| otherwise? Is this a fault how the power bank or macOS implements
| power negotiation, or is this scenario simply unaddressed in
| USB-C?
|
| 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?
| KeplerBoy wrote:
| By converting to USB A you cut out USB-PD completely from the
| equation. At that point the macbook simply provides 5V as it
| would to any legacy downstream device.
| Piskvorrr wrote:
| It's even simpler, I think: you're forcing it to avoid a PD
| negotiation, and fall back to the lowest common denominator,
| "500 mA on the PWR line supplied to the USB device". This goes,
| I believe, as far back as USB 1.1, as a slow-but-generally-safe
| power source for things that are barely more than "use USB PWR
| and GND as a dumb 5V source."
|
| 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.
| stephen_g wrote:
| PD can certainly do it, but most laptops don't choose to
| support high power sourcing, only providing 5V at max 900 mA
| for devices or taking high power as a sink (charging the
| laptop).
| mschuster91 wrote:
| > 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?
|
| 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...
| noroot wrote:
| I have the same issue, but the other way around. I cannot
| charge my laptop (framework 13, amd) from my power bank. Which
| sometimes would be super useful.
|
| I don't know nor understand why it doesn't work and if it's a
| bug in the power bank or the laptop
| nfriedly wrote:
| I have a Framework 13 and I've found that it's fairly finicky
| about what power sources it will accept. Anything 60W and
| higher seems to mostly work, but lower wattage chargers are
| much more dicey.
|
| 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.
| Kirby64 wrote:
| > Does USB-C not have a way to indicate that a potential power
| source is a battery so that the MacBook can charge it if it's
| plugged in to power, and reverse roles otherwise? Is this a
| fault how the power bank or macOS implements power negotiation,
| or is this scenario simply unaddressed in USB-C?
|
| 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.
| quesomaster9000 wrote:
| I'd have thought that iPhones would have sane defaults with
| USB-C, but it's a real pain when using USB-C to provide
| tethered internet to a laptop. No, I don't want the phone to
| charge the laptop, they both have batteries of their own
|
| 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.
| MarkusWandel wrote:
| USB-C has obfuscated things but I was hoping the following would
| work:
|
| 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.
| nucleardog wrote:
| My wild guess would be that, yes, that cable is just a naive
| splitter. The only real use case I could think of that would
| work would be taking a USB-C port and making it accept either
| USB-C or USB-A devices without having to dig around/swap
| adapters/etc. I say that because as far as I'm aware (though
| I'm having trouble digging up an authoritative source right
| now), there's no way for USB devices to share data lines. Even
| cheap "passive" hubs and things all have ICs to present
| themselves as a USB device and sit between the host and the
| downstream devices. With the older USB specs you could still
| get some power even without the data lines, but with USB-C you
| need the data lines to negotiate power delivery. I don't think
| there are any software-level changes would make that setup
| work.
|
| 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.
| MarkusWandel wrote:
| Thanks for that. The longer-term goal is to make a "dock" for
| my elderly mom's phone that lets her use it as a tiny (her
| eyes are still good) pseudo-desktop setup with keyboard and
| mouse. She often ends up with her phone as her only
| communications device when things go wrong (again) on her
| laptop and this would give a good email experience (she's a
| skilled touch-typist). Any pointers to a cheap USB-C dock on
| Ali that does the job?
|
| 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.
| bluGill wrote:
| USB-C never defined a Y cable and so they never figured out how
| that would work. If such a cable works anywhere it is either
| luck, or there is some chip inside that checks for power
| messages from either end but otherwise looks like a straight
| through cable. Even then it will be tricky because if the two
| devices want different voltages from the charger only one can
| get their way.
|
| 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.
| MarkusWandel wrote:
| Heh, if you want a really atrocious USB power violation...
| Costco sold some extremely bright flashlights (think car
| headlight bright, and also usable as a self-defense weapon in
| the spirit of the old D-cell Maglites) before Christmas, that
| have an USB charge socket. Needless to say they include a
| charge cable but no charger.
|
| 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.
| nfriedly wrote:
| > _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.
| lupire wrote:
| No need for weird racism.
|
| American companies like Skullcandy do this too.
| nfriedly wrote:
| Fair enough, edited.
| MarkusWandel wrote:
| The flashlight comes with an USB A->C charging cable, as
| do the (low end) smartphones we have (along with USB-A
| power adapter for the phones). Thus probably no PD
| negotiation. Right?
| nfriedly wrote:
| Aah, yes, the USB-A side always provides power, no
| negotiation needed for that aspect. There is still
| supposed to be some level of negotiation before drawing
| that much current (often just checking resistance,
| similar to the USB-C "dumb" mode), but obviously the
| device skipped that also.
| ianburrell wrote:
| A lot of flashlights and cheap gadgets have USB-C port
| but can only charge from USB-A port. The reason is that
| they cheaped out on including the resistors that signal
| legacy USB mode. The USB-C to USB-A cable has the
| resistors.
|
| The smartphones should have proper USB-C port, I haven't
| heard of one with charging problems, and included USB-A
| cable cause cheap.
| xg15 wrote:
| Isn't this exactly what USB-C docks are for?
|
| 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.
| bluGill wrote:
| That is what a dock is for. OP wants a simple and cheap
| cable instead which isn't really possible in the generic
| sense (though it might work in some limited way)
|
| 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)
| MarkusWandel wrote:
| The docks we have around here at work all use Displaylink
| chips. So it would work if the phone had the (software)
| Displaylink driver, no Displayport video capability
| required on the USB-C port. But I'm guessing that's
| unlikely.
| MarkusWandel wrote:
| Hmmm, it occurred to me, I'm sitting in front of a laptop
| connected to a (power delivery) USB-C dock. So unplugged
| the laptop and plugged the cable into my phone instead
| (very basic, Moto G Play 2023). What happened? Almost
| nothing! The phone reported an audio output device, but did
| not charge, and the keyboard and mouse plugged into the
| dock did not get recognized either. Not encouraging.
| MarkusWandel wrote:
| Well, the Kensington dock at work did not work (for
| delivering power to the phone and letting keyboard and
| mouse be used) - in fact it did none of those things. But
| ordered this cheapie from Ali:
|
| https://vi.aliexpress.com/item/1005007015739540.html
|
| which does claim to work with various smartphones. We'll
| see.
| xg15 wrote:
| Would be interested to know that as well. Good luck!
| harrall wrote:
| While not in a Y cable format, there are small USB-C hubs that
| can do this.
|
| 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.
| CableNinja wrote:
| This article, and all comments, have reminded me yet again of my
| anger at the not so universal USB formats.
|
| 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
| TheAmazingRace wrote:
| Honestly, SCSI was more straightforward than the quagmire that
| is current USB standards, especially over Type-C. I can't trust
| the quality of cables or what they are capable of on the
| surface. I really need to do my homework to ensure I get the
| right transfer speeds and power delivery.
|
| 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...
| Tharre wrote:
| Just to avoid confusion, there is no such thing as a "PD
| certified" usb-c cable. All usb-c cables, by any version of
| the standard, have to safely support at least 3 amps at 20V.
| And for 5 amps they have to contain an active marker chip
| that's involved in the PD negotiation.
|
| 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.
| tredre3 wrote:
| > you dont have to figure out which way the cable goes now, but
| hardware designers are suffering because of the shenanigans
| that is USB
|
| 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.
| bloopernova wrote:
| Somewhat related: For USB C cables, get a CaberQU pin/line
| checker: https://caberqu.com/
|
| 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...
| causi wrote:
| Wow that is some _massively_ overpriced crap right there. Forty
| dollars for a USB continuity tester with a basic plastic case
| that only does type-C cables. Meanwhile you can get one, with
| acrylic case, that does types A, B, C, Micro, and Micro 3.0 for
| $17 off Amazon or $11 off Aliexpress.
|
| https://www.amazon.com/Treedix-Tester-Checker-Acrylic-Chargi...
| Tharre wrote:
| It's not just a continuity tester like the one you linked
| from amazon though. The Kickstarter page is light on details,
| but it can at the very least communicate with active cables
| to determine amperage and data speeds.
|
| Add to that a microcontroller, screen and software and the
| price doesn't look unreasonable to me, especially for a small
| project like this.
| aidenn0 wrote:
| There were also digital cameras that supported OTG in order to
| print to portable printers (usually just one or two models made
| by the same manufacturer).
| p0w3n3d wrote:
| Android is a Linux. This means that it can have a keyboard, mouse
| and other periferials. You could (and probably can) even burn a
| CD using an Android phone. One of the nice things in OTG was to
| connect an external screen which is turning the phone to a full
| blown computer. Or a media player...
|
| HAHAHA! NAIVE 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
| scarface_74 wrote:
| Android being based on Linux doesn't mean it has all of the
| capabilities of a Linux distribution anymore than iOS being
| based on BSD or even more relevantly being a fork of MacOS
| means it can do everything that Macs can do.
|
| 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.
|
| https://imgur.com/a/wyV4ReK
|
| Of course my laptop supports powering and video at full
| brightness over one USB-C port
| p0w3n3d wrote:
| What I describe is my genuine experience. I had a phone with
| usb otg with MHL. And netflix app didn't send video to the
| screen of the TV. It sent only text of subtitles. Because of
| some stupid limitations.
| scarface_74 wrote:
| MHL is different than using the more modern USB-C Alt mode.
| In the image link I posted above, that was my iPhone
| connected via USB C watching "Breaking Bad" on Netflix
| while I was waiting on my flight in a Delta lounge.
|
| 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/
| Tharre wrote:
| I'm honestly a bit confused about what your actual point
| is. Most people would agree that HDCP is hostile to
| consumers, but what does any of that have to do with USB or
| for that matter android? It sounds to me your problem is
| that your particular MHL implementation just didn't support
| HDCP. And AFAIK MHL has nothing to do with the USB standard
| other then reusing the connector to speak their protocol.
| p0w3n3d wrote:
| You're right, if this MHL implementation didn't have HDCP
| it would behave exactly like that. Sad.
|
| 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
| Tharre wrote:
| > Truly this sounds to really complicated that a phone
| which is indeed a computer cannot do computer things.
|
| 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.
| scarface_74 wrote:
| > Go back a couple of years and you'll find tons of posts
| of people trying to get Netflix working on linux
|
| 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
| Tharre wrote:
| > 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.
|
| ? 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.
| scarface_74 wrote:
| > Truly this sounds to really complicated that a phone
| which is indeed a computer cannot do computer things
|
| 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.
| fsflover wrote:
| > Android is a Linux.
|
| Can you run unmodified LibreOffice or Wine on it? I can on my
| Librem 5.
| nine_k wrote:
| I suppose you cannot watch Netflix on anything not having a
| certified DRM-supporting display tract, up to the encrypted
| HDMI interface. Were it not so, you could _PIRATE_ a movie for
| free! (Now you need to pay for a $30 HDMI splitter, or
| something.)
|
| I don't do Netflix, so I don't care. Youtube works fine.
| p0w3n3d wrote:
| Yeah all I think about when I connect a device to a monitor
| is PIRATING ARRR!
| mmmlinux wrote:
| Does android actually support USB CD drives?
| dotancohen wrote:
| Reading, yes. Writing, I have not tried.
| p0w3n3d wrote:
| I believe I have seen an external CD drive for android, but
| not sure. It was quite expensive, but maybe because it was
| having some middleware
| jsmith45 wrote:
| In my experience not many OTG devices actually used
| (mini-/micro-)AB ports, instead using just normal (mini-/micro-)B
| ports. The adapters generally just used a (mini-/micro-)B plug
| with the id pin wired like an OTG A plug. This does mean you can
| technically connect these adapters to non OTG products, which the
| spec writers wanted to avoid, but this simply meant the adapter
| didn't work.
|
| 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.
| DidYaWipe wrote:
| Man, I hate that name. Why not just call it "host mode," which
| actually conveys information?
| lxgr wrote:
| Back in the day when cameras still took better photos than
| phones, I've always wanted to backup vacation photos without
| bringing a computer.
|
| 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!
| netsharc wrote:
| I went on a long trip with a mirrorless camera and a SanDisk
| 500GB portable disk. My "computer-less" backup solution was a
| Pi-esque machine with USB3 (a RockPi), a powerbank, a card
| reader, and connecting my phone over USB and tethering it. This
| gave the RockPi an IP I could ssh into, and I'd ssh from the
| phone and ran rsync to copy the images from the SD card in the
| reader to the SanDisk portable drive.
|
| 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.
| nfriedly wrote:
| > _[1] My first smartphone was the HTC Thunderbolt. No one, not
| even me, will speak of that thing with nostalgia. It was pretty
| cool owning one of the first LTE devices on the market, though.
| There was no contention at all in areas with LTE service and I
| was getting 75+Mbps mobile tethering in 2011. Then everyone else
| had LTE too and the good times ended._
|
| 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.
| qwertox wrote:
| > for most of the '90s RS-232-ish serial and its awkward sibling
| the parallel port were the norm for external peripheral
|
| 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.
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