texy
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:16 pm

Hi,

for Pi linux, will any usb hub do, or does it need to support specfic hubs?

I guess another way of asking is, are the drivers 'generic'?

For example, this powered hub on ebay quotes linux 9 as one of the OS's, so I,m thinking it will work ok on the Pi -

http://www.ebay.co.uk/itm/7-Po.....1531wt_952

Cheers,

Texy
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
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drgeoff
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:20 pm

Hubs are OS agnostic.

(I have ordered the same item from another ebay supplier for 51p less )

texy
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:29 pm

Cheers!!

T.
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Chromatix
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:37 pm

Several types of basic USB peripherals have a standard protocol and will therefore work anything-to-anything, as long as the manufacturer is competent.  These include:

- Hubs (powered or otherwise).

- Chargers/supplies with USB physical plugs/sockets.

- Keyboards - including wireless.

- Mice - including wireless.

- Joysticks (but not necessarily gamepads).

- Hard disks, flash drives and card readers.

- Microphones, speaker sets, headsets and external sound modules.

There is also a standard protocol for webcams, but this was a late development so not all webcams use it.  Most webcams are however supported by either UVC or GSPCA drivers in Linux.

For anything not in the above list, it is worth researching or asking before you buy.
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texy
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:40 pm

Many thanks. Hub ordered, and saved 51p

T.
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
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Chromatix
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Re: Suitable powered USB hubs

Mon Mar 05, 2012 8:44 pm

Come to think of it, perhaps the above is FAQ and/or wiki material.
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drgeoff
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Re: Suitable powered USB hubs

Thu Mar 08, 2012 11:39 am

drgeoff said:


Hubs are OS agnostic.

(I have ordered the same item from another ebay supplier for 51p less )



See my "review" of this item at http://www.raspberrypi.org/for.....-5/#p50271.

the_lurker
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Re: Suitable powered USB hubs

Thu Mar 08, 2012 5:29 pm

You might want to watch this video.


drgeoff
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Re: Suitable powered USB hubs

Thu Mar 08, 2012 6:07 pm

the_lurker said:


You might want to watch this video.


I came back here to update my "review" to say "Avoid" and saw the link to the video.  I can confirm that what you see in the video is not a one-off duff PSU.

Prior to seeing the video, I had myself noticed that the PSU voltage dropped to 4.7 volts even when it was powering only the hub without any peripherals plugged in.  I had also opened the PSU and was rather shocked at how poor it is in terms of build quality, performance and safety.  I hadn't gone to the extent of the video maker with several meters, nor had I taken the transformer apart.

I think a complaint to the supplier is in order.

colincoach
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Re: Suitable powered USB hubs

Thu Mar 08, 2012 7:50 pm

Hmmmm, a bit concerning, as I too bought one of these after seeing this post. Is it just a case of junking the PSU and getting another one, is the hub itself of good enough quality?

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Re: Suitable powered USB hubs

Thu Mar 08, 2012 8:07 pm

...and this is why I qualified my post with "if the manufacturer is competent".

I'll let others comment about this specific hub's quality, but clearly that PSU is utterly worthless.
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piglet
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Re: Suitable powered USB hubs

Fri Mar 09, 2012 10:15 am

I got two of these - though with "2A power supply". I was concerned at the lack of weight in the PSU. When PSU plugged in to the hub my PC wouldn't even boot!

While I've got a multimeter which I know one end from the other I'm no sparky, so don't know how to safely evaluate the safety of the PSUs.

The hubs themselves don't look too bad...but what do I know! Should I just ditch the PSUs and find something better quality? (If so, what?)

One of Liz's posts about PSUs for the Pi was that the ones the Foundation would be selling would be of the right level of quality....however that never happened. It's now turned into "Fanell sell stuff, look on their website". I had hoped to buy power supply for Pi and hub for Pi from the foundation shop in the knowledge that I'd be getting something that was known to be appropriate...and safe. *Sigh*

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rurwin
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Re: Suitable powered USB hubs

Fri Mar 09, 2012 10:32 am

If you buy from Farnell, or RS, or Amazon, or eBuyer,  or PC World, or Dixons, then you can be fairly sure that what you are buying is safe and appropriate. And if it isn't then you can report them to the Office of Fair Trading, Watchdog, Which and the Small Claims Court.

If you buy from eBay, you get it cheap.

Caveat Emptor and TANSTAAFL.

RussIT
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Re: Suitable powered USB hubs

Fri Mar 09, 2012 11:39 am

I have this exact same hub but with a 3A PSU, I just measured the voltage with my htc phone and a 2.5 inch hard disk attached and the voltage is about 5.2V at the USB connector on the hub.

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Re: Suitable powered USB hubs

Fri Mar 09, 2012 1:02 pm

OK, so if we ditch the PSU, is the hub itself worth buying? I have plenty of PSU"s, but thought a 7 port hub might be handy when playing with the Pi....

drgeoff
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Re: Suitable powered USB hubs

Fri Mar 09, 2012 2:03 pm

Robert said:


OK, so if we ditch the PSU, is the hub itself worth buying? I have plenty of PSU"s, but thought a 7 port hub might be handy when playing with the Pi....


As I posted previously, I took the hub apart (it is only pushed together without any screws) and noticed that the PSU input is wired straight to all 7 USB "output" sockets and the "input" socket.  This is bad practice as it means that the hub's external supply is fighting with the 5 volts from the host USB that is connected to the hub.  Not so important if you want to power the RP by a USB cable from the hub to the micro-USB socket.  But certainly not a nice thing if you want to use the hub with an ordinary computer or other USB host device.

I contacted the ebay seller saying I was rejecting the item as unsatisfactory and asking for a full refund.  (I gave him the link to the Utube video).  He has agreed to refund me and is sending a return envelope.

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Re: Suitable powered USB hubs

Fri Mar 09, 2012 10:37 pm

Ah, i understand now - thanks for that clarification!
With five kids and multiple gadgets it doesn"t sound like a hub I"d want in the house...

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Re: Suitable powered USB hubs

Sun Mar 11, 2012 6:30 pm

So I take it a powered USB hub can be used to power the PI too?

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Re: Suitable powered USB hubs

Sun Mar 11, 2012 6:51 pm

spender_uk said:


So I take it a powered USB hub can be used to power the PI too?


Yes, provided all the USB peripherals are also supplied by a powered USB hub, the R-Pi should stay within the 500mA that a powered USB port is normally able to provide.  Obviously the hub's own power supply needs to be strong enough to cover everything.

A commonly discussed configuration is where a single powered hub is used for both purposes, with a MicroUSB cable running from the hub to the R-Pi's power input.  This in particular should work quite well.
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Re: Suitable powered USB hubs

Sun Mar 11, 2012 9:25 pm

rurwin said:


If you buy from Farnell, or RS, or Amazon, or eBuyer,  or PC World, or Dixons, then you can be fairly sure that what you are buying is safe and appropriate. And if it isn't then you can report them to the Office of Fair Trading, Watchdog, Which and the Small Claims Court.

If you buy from eBay, you get it cheap.

Caveat Emptor and TANSTAAFL.


But eBuyer and Amazon both sell this hub. How are we supposed to know what's good and what's crap? I ordered one from eBay for £3.49 then finished reading the thread - I just informed the seller that I am cancelling under the Distance Selling Regulations.

This is a bit of a problem - can't go round Maplin or Currys with a meter demanding to test all the power supplies...

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rurwin
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Re: Suitable powered USB hubs

Sun Mar 11, 2012 10:20 pm

JonB said:


rurwin said:


If you buy from Farnell, or RS, or Amazon, or eBuyer,  or PC World, or Dixons, then you can be fairly sure that what you are buying is safe and appropriate. And if it isn't then you can report them to the Office of Fair Trading, Watchdog, Which and the Small Claims Court.

If you buy from eBay, you get it cheap.

Caveat Emptor and TANSTAAFL.


But eBuyer and Amazon both sell this hub. How are we supposed to know what's good and what's crap? I ordered one from eBay for £3.49 then finished reading the thread - I just informed the seller that I am cancelling under the Distance Selling Regulations.

This is a bit of a problem - can't go round Maplin or Currys with a meter demanding to test all the power supplies...


But RussIT said,


I have this exact same hub but with a 3A PSU, I just measured the voltage with my htc phone and a 2.5 inch hard disk attached and the voltage is about 5.2V at the USB connector on the hub.


I would trust the one from eBuyer, and I would trust the one from Amazon, if it is being sold by Amazon and not a Marketplace seller. It sounds as if at least some sellers are selling it with a decent power supply. Whether those units also have the five-volt feedback problem I don't know and I would worry about that. But it wont break anything even if it does cause problems. It will just put that USB port out of action for an hour. On the other hand it is not good practise to have two power supplies fighting over supplying power. You could have over an Amp flowing because one is supplying 4.75V and the other 5.25V.

You've got two decent choices here. Either buy this one from eBuyer (who will understand you when you complain) and test it when you receive it, or buy a big name device from a big name distributor with the expectation that they wont ship rubbish and if they do they will support you.

You probably don't want to buy a different no-name device, since you don't know what problems that one might have.

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Re: Suitable powered USB hubs

Sun Mar 11, 2012 10:35 pm

This is the one I got from ebay as it specified that it had a 3 amp PSU, there were others form other sellers cheaper but this was the only one I could find with this power rating

http://www.ebay.co.uk/itm/2805.....1423.l2649

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Re: Suitable powered USB hubs

Sun Mar 11, 2012 11:01 pm

JonB said:

But eBuyer and Amazon both sell this hub. How are we supposed to know what's good and what's crap?
Search for reviews. If you don't find any real customer reviews that say it's good, then don't buy it.

This one has one review I can find, and that says it is rubbish.

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Re: Suitable powered USB hubs

Tue Mar 13, 2012 10:05 pm

Well it turned up with a 1A supply which straight away I noticed felt too light, so I opened it up to take a look at what is inside. Well. There is a tiny transformer about 1cm cubed, no way is it going to handle an amp! The hub (as advertised here) came apart in my hands, and I was struck by the cheapness of the PCB. I have an unpowered £5 hub (Technika) from Tesco that looks better than this.. Anyway, care of the Distance Selling Regulations, it is going back.

Oh, also I tested it with a multimeter. voltage spike on connection to 12.5v then back to 4.7v without load, for the record.

colincoach
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Re: Suitable powered USB hubs

Wed Mar 14, 2012 8:29 am

JonB said:


Well it turned up with a 1A supply which straight away I noticed felt too light, so I opened it up to take a look at what is inside. Well. There is a tiny transformer about 1cm cubed, no way is it going to handle an amp! The hub (as advertised here) came apart in my hands, and I was struck by the cheapness of the PCB. I have an unpowered £5 hub (Technika) from Tesco that looks better than this.. Anyway, care of the Distance Selling Regulations, it is going back.

Oh, also I tested it with a multimeter. voltage spike on connection to 12.5v then back to 4.7v without load, for the record.


Well like others I ordered the £3.49 one from ebay before the inspection video appeared, so challenged the supplier that it wasn't to spec and they have offered me a full refund and I have asked for a prepaid envelope to be provided so I can send the defective goods back.

To be fair on the supplier they have not quibbled about this at all!!

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