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USB Gamepad problem

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Beretta:

could be a power problem like was suggested.. heck i've had problems before just by adding an extension.. apparently 6 feet of cable was just enough power loss to make some things not work.. and i've had some boards that wont work with some usb devices.

so ya power could be the problem.

Avinitlarge:

It could be power, I just dont know. I did google it and it seems to be a very common problem which no one seems to beable to sort out. Im not bothered now, Ive now got 5 extra ports for connecting various gamepads, Card readers etc.

u_rebelscum:


--- Quote from: Beretta on October 09, 2009, 12:34:30 am ---... heck i've had problems before just by adding an extension.. apparently 6 feet of cable was just enough power loss to make some things not work....

--- End quote ---

FWIW, about 99% of all USB extension cords are out of spec.  USB 2.0 specs forbids plain extension cords.  However, USB 2.0 allows for "one port unpowered hubs", which an on spec extension cord needs to be.  The reason USB 2.0 doesn't like raw extensions is the power & signal degradation, apparently mostly caused by the extra contact point (between the extension and the original cord), and secondly the extra length.

And yes, I use out of spec extension cords fairly regularly.  And usually they work fine.  But when a USB problem comes up, it's one of the first times I check.

Beretta:

ah i was'nt aware of that USB 2.0 forbidden it.

actually the problems i've had was with 1.1 devices..

namely psx-usb converters & hacked xbox (original) controllers.. especially for example with rumble cranked up..

i've had some boards that could'nt support them with or without the extension.. i had this old 64mb thumb drive (usb1.1) that would'nt work on this one particular board with the extension cable.

i reckon those just end up being power issues and or weak boards.. 500ma goes pretty quick, in some cases i dont even think they was putting out that much to start.

u_rebelscum:


--- Quote from: Beretta on October 10, 2009, 04:00:38 am ---ah i was'nt aware of that USB 2.0 forbidden it.

actually the problems i've had was with 1.1 devices..
--- End quote ---

Not that is matters, but 1.0 okayed extensions, 1.1 depreciated them (recommended against them), and 2.0 said they can't be used.


--- Quote ---i reckon those just end up being power issues and or weak boards.. 500ma goes pretty quick, in some cases i dont even think they was putting out that much to start.

--- End quote ---

Yeah, probably is a power problem, but not exactly the why you're thinking.  USB devices can request up to 500mA, but most only request 100mA (most thumb drives, mice, keyboards).  100mA goes even quicker than 500mA.  Which is why "one port hub extensions" are okay. The hub makes its own request, and can request 200-500mA, and then the device make its 100mA request, and the one port hub can supply the full request even with the extra cable.  And the unpowered hub wouldn't allow the full 500mA request, since the hub+extra cable is "using" 100mA; all unpowered hubs are spec'ed* to use 100mA and only allow up to 400mA total of all devices pluggin into it.

(*again, like extension cords, this spec isn't always followed)

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