Apple Keyboard USB HUB problem.

Discussion in 'Mac Accessories' started by RRuiz, Mar 23, 2010.

  1. RRuiz macrumors newbie

    Joined:
    Oct 7, 2009
    #1
    Hi, I bought this keyboard recently ( http://store.apple.com/us/product/MB110LL/A?fnode=MTY1NDA1Mg&mco=MTA4Mzc4ODA ), it has 2 USB ports on the side. In 1st I plugged the mouse and the other I plugged this speakers ( http://www.logitech.com/index.cfm/notebook_products/speakers/devices/200&cl=roeu,en ). The problem is that when I'm in Windows 7 it says the hub has not energy enough to connect the devices, and the speakers do not work. Now when I'm on Mac OSX the mouse and the speakers work perfectly. Does anyone have an explanation for that?

    Sorry about my english, and thank you.
     
  2. Gonzo3333 macrumors 6502a

    Gonzo3333

    Joined:
    Mar 30, 2009
    Location:
    Chicago, IL
    #2
    I am pretty sure that the USB ports on the keyboard are not powered.
     
  3. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #3
    I'm pretty sure one of the 'pins' within every USB port is a 5V powered pin.

    As it stands now, the OP has had the speakers working in OS X, just not Windows 7.

    It may not be enough power for the speakers to work effectively, but ALL USB ports do indeed transmit some power.

    EDIT: Indeed...I found this on Wikipedia:

    "The USB 1.x and 2.0 specifications provide a 5 V supply on a single wire from which connected USB devices may draw power."

    That being said, since the keyboard has no other source of power...i.e. it is essentially a non-powered hub, both ports must share the 5V and at that level it's doubtful you will have much success driving the speakers AND mouse AND keyboard with that small an amount of power...as Windows is pointing out.
     
  4. Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #4
    Same problem,

    The Xbox 360 controller works in the keyboard in Mac OS but not in Windows. I'm guessing Windows puts some kind power-saving thing on the USB ports.

    Still, if anyone knows how to fix this, that would be great.
     
  5. flynz4 macrumors 68040

    Joined:
    Aug 9, 2009
    Location:
    Portland, OR
    #5
    Your best solution would be to get a USB powered hub. You can connect both your speakers and your keyboard to it, and it should then work fine.

    When we were defining the USB specification, we had significant debates on whether we should allow non-powered hubs... or if we should require all hubs to be powered... delivering the full 0.5A @5V (2.5W) to every port. On the pro-side... the current spec allows low powered devices (such as your mouse) to be plugged into a keyboard. The obvious con is the reduction in ease-of-use in not knowing if an individual port is high or low powered.

    /Jim
     
  6. Ainze macrumors regular

    Ainze

    Joined:
    Feb 28, 2010
    #6
    Very true flynz4. To be honest, it's crossed my mind often to get a powered hub, but I guess convenience gets the better of me every time.

    Still, either way it doesn't really solve the problem of Mac OS vs. Windows. Before this keyboard, I used to use a USB 1 non-powered hub, and could have a keyboard, mouse, and two controllers (or a pen drive in place of one of those), all at the same time. Come to think of it, that worked fine on Windows too. I guess that makes the question specifically about how only the Apple keyboard works in either OS.
     
  7. flynz4 macrumors 68040

    Joined:
    Aug 9, 2009
    Location:
    Portland, OR
    #7
    I believe you are not realizing that there are two things that occur:

    1) The ability of a device to actually work (irrespective if it meets the spec)
    2) The policies of a computer which enable a device (for example, if the spec is not met)

    One of the things that USB allows is for each device to report its capabilities and/or requirements. It is quite possible the the combined power requirements of your unpowered hub, keyboard, and USB speakers exceed the amount of current (0.5A) available from the USB port on your computer... yet still within the range where they might operate from a practical standpoint.

    It sounds to me like the Windows USB driver is determining that the combination of devices exceeds the specification, and hence is not enabling your speakers. I have no idea if Apple has similar policies in its USB drivers.

    /Jim
     
  8. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #8

    THIS seems to be the 'problem'. One OS says it's ok, while the other is a lot more restrictive about what will work.
     

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