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Help! USB hub trouble

Posted: Sat Feb 16, 2013 11:35 am
by odog
Hi,
So I am new to the pi and am having a bit of trouble. I bought a maplin kit of everything you need for the raspberry pi (including the pi). I booted it up and if i plugged the mouse and keyboard into the 2 available slots on the pi, they would work fine. When I connect my powered USB hub and plug the mouse and keyboard into the hub they don't work :(.

If someone could help me with this it would be greatly appreciated

Re: Help! USB hub trouble

Posted: Sun Feb 17, 2013 4:23 am
by Mobius
Did the hub come with the Pi? Or did you check the "Verified Peripherals" to see if it was on the list? Some hubs larger than 4 ports won't work right. Is the hub powered? Is the hub properly connected to one of the Pi USB ports? Have you tried both Pi ports? If those items work directly connected to the Pi, they should work on a powered hub. One other thing to try would be to use the hub without power. It might be feeding power back into the Pi through the USB port and messing things up.

Re: Help! USB hub trouble

Posted: Sun Feb 17, 2013 3:47 pm
by pluggy
I'd be prepared to believe anything with hubs. I have a powered hub that works perfectly on a 'B' (Any 'B', I have 3 different types) but won't entertain an 'A'. If it works be thankful, if it doesn't, you have to work something out. A powered hub is often held out as as a Pi cure-all, it isn't and can often causes as many problems as it solves.

I don't see a particular problem with 'back powering' a Pi from a non descript hub (its against the official USB spec and quality stuff shouldn't do it, but the Pi is so compromised on the USB front anyway...) . If it works, do it, It does take that damned polyfuse out of circuit.

Re: Help! USB hub trouble

Posted: Sun Feb 17, 2013 8:17 pm
by Mobius
Pluggy's comment got me to thinking a bit about the different models. It's possible that even with a powered hub that the polyfuses in the USB outputs of the earlier Pi's (like mine) could contribute to the problem. The input polyfuse costs you some voltage and the USB ones will cost you some more - all because the polyfuses have an internal resistance that cause a voltage drop. I shorted across the polyfuses on my card and now I actually use the Pi to power the hub.

Re: Help! USB hub trouble

Posted: Sun Feb 17, 2013 8:27 pm
by odog
Thanks for the help guys but what do you actually suggest I do?

Re: Help! USB hub trouble

Posted: Sun Feb 17, 2013 11:25 pm
by pluggy
Contact Maplin and explain the bits they sell don't work together.