back to article New USB spec offers two-way power flows AND double-sided plug

The USB Promoters Group has loosed the USB Power Delivery v2.0 and USB Billboard Device Class v1.0 specifications on the world. Don't snore, dear readers, because these specs make it possible to reverse the role of devices popped into USB plugs. As the 534-page Power Delivery v2.0 spec (contained in this 42-megabyte .zip file …

  1. Anonymous Coward
    Anonymous Coward

    Why not just get rid of a "host" requirement in USB? USB always just seems to be behind other technologies. It always had an inferior amount of power it could provide, one device had to be a host, so that mean you couldn't use a device on a device. Maybe it is time to shed some of the legacy support and actually produce something that would benefit all. They change connectors way too often; you had the whole mini and micro and all they did was reduce one dimension. Why they even had the other is beyond me; they weren't that far apart.

    USB was an idea copied off of others and they continue to copy, but not very well either.

    1. ecofeco Silver badge

      Easy copying between devices has been deliberately crippled all these years.

      Care to guess why? Hint: it has its own acronym and sues poor people.

      1. Francis Boyle

        So DRM was behind the fact that you can't copy from one flash drive to another. Nothing to do with the fact that flash drives are cheap devices that don't include a cpu and that USB deliberately uses the cpu to make that cheapness possible. But that's a bring technical explanation. Conspiracy theories are more fun.

        1. Gary Bickford

          Every flash drive has a cpu

          Actually, every flash drive has a tiny cpu, which is what decides where to put data, spreads writes around the chip(s), and tracks bad sections. If it's a self-encrypting drive, the CPU + other hardware handles that as well. Someone even managed to get Linux running on one.

    2. Anonymous Coward
      Anonymous Coward

      Wasn't that due to the need to maintain a strict topology which simplifies the logic (and isn't relative simplicity one reason USB has become so ubiquitous in contrast to say 1394)? Allowing the reverse direction at will to me sounds like a recipe for trouble especially when electrical power is involved.

    3. JeffyPoooh
      Pint

      Reverse Power Flow - Puh! The Raspberry Pi allows that since Day 1

      When you connect your Raspberry Pi to a powered USB Hub of the sort made in China, then you will find that the USB Hub provides 5V on the Host port (due to a diode or equivalent switching scheme being left out of the design for various reasons), and the Raspberry Pi will accept this power and turn on, even when the R-Pi's normal power adapter is Off / disconnected / tossed out a window.

      It's the 'Hey! Why is my Raspberry Pi running?' problem.

      The solution is to open up the $7 USB Hub and cut a trace. Then the Hub *requires* its own power adapter (as opposed to being optional).

    4. handle

      @ AC opening poster: research > rant

      "They change connectors way too often; you had the whole mini and micro and all they did was reduce one dimension. Why they even had the other is beyond me; they weren't that far apart."

      If you do a little reading up you will find that micro USB connectors are actually a lot more durable than mini USB.

      "USB was an idea copied off of others and they continue to copy, but not very well either."

      Like what? FireWire? How much do you think a FireWire mouse would cost?

  2. ecofeco Silver badge

    "Your mobe could charge your laptop"

    I suppose it could... after I buy all the new kit it will require, like the laptop and phone and cable and what the hell, a desktop while I'm at it because that's where I still do most of my work.

    So let's see, upgrade to new standard will cost me roughly....

    I know, I know, nothing new here, but once in while, just once in a damn while I would like to see more BACKWARD compatibility. I'm not bloody rich!

    (I complain because something happened to USB cables about a year after I bought my last mobe. They don't work with it. That was just 2 1/2 years ago.)

    1. Blergh

      Re: "Your mobe could charge your laptop"

      I'm not worrying about having to upgrade because I just will as I get devices that has the functionality, like I always do.

      My main issue was regarding "Your mobe could charge your laptop", so how will I be able to get it to not do that? Maybe I want the laptop to charge the mobile instead. How does it know which batteried device should be sending the power in which direction? This would presumably be most of an issue for something like a battery extender pack. Unless that keeps a strict input port and output port, otherwise the mobile might start charging the battery pack instead of the other way around.

    2. Anonymous Coward
      Anonymous Coward

      Re: "Your mobe could charge your laptop"

      "I complain because something happened to USB cables about a year after I bought my last mobe. They don't work with it. That was just 2 1/2 years ago."

      I have no idea what you are doing, but I have ancient USB1 devices that work on USB 3 kit. I have no idea why you feel the need to rip and replace, as the beauty of USB is it is compatible.

      My guess is you are using those shit 99p cables from eBay.

    3. handle

      Re: "Your mobe could charge your laptop"

      "(I complain because something happened to USB cables about a year after I bought my last mobe. They don't work with it. That was just 2 1/2 years ago.)"

      The price of copper went up.

  3. Ole Juul

    History

    This spec could therefore offer a way to turn a monitor or other device into a power source

    The Amstrad had the power supply in the monitor.

    1. handle
      Trollface

      Re: History

      "The Amstrad had the power supply in the monitor."

      Shh - don't tell anyone! Apple invented that concept with the iMac!

  4. Anonymous Coward
    Anonymous Coward

    New Standard USB connector in iPhone 7?

    1. dogged

      shyeahright

  5. Old69

    USB reverse power

    When my main PC PSU was manually switched off it was noticed that it still showed signs of stand-by power. It was tracked down to an external powered USB hub that was apparently feeding 5 volts back into the PC's stand-by line via its USB port.

  6. Anonymous Coward
    Anonymous Coward

    There are already plenty of USB devices with 2 way power flows, but unintentionally due to bad design.

    I have a powered USB hub on my desk, which keeps my desktop's motherboard alive if I pull the mains lead out. I guess either the motherboard designer or the hub designer skimped on a diode.

  7. Anonymous Coward
    Anonymous Coward

    Cool!

    Come on admit it, USB is pretty cool. Before there was USB hooking up devices was a real pile of shite. Apple still try and fight it with their own proprietary standards but USB is still king.

    1. Anonymous Coward
      Anonymous Coward

      Re: Cool!

      Will be better with reversible pugs..Gaaahhhh!

      1. Anonymous Coward
        Anonymous Coward

        Re: Cool!

        It will take USB to a whole new level!

  8. DNTP

    When this becomes real I'm going to take a bunch of USB devices and create a circle chain just to see what happens. If the electricity keeps moving around the circle I calculate it should power all the things, forever.

    "Perpetual energy? How one HIGH SCHOOL GRADUATE found a secret BIG POWER doesn't want you to know"

    1. Francis Boyle

      You'll create a feedback loop that will generate a metastable Higg's boson and destroy the universe.

      1. Midnight

        That could be as bad as trying to Google Google.

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