Problems with external 5V supply
Supriya s KARANTH
supriya.karanth at stericsson.com
Wed Apr 11 08:06:59 UTC 2012
You would still need the HW change + SW change.
This is because the devices (like mouse/keyboard/MSC) will monitor the VBUS (5V) line from the OTG port of snowball and then only send a connect signal. With the HW change we are going to provide 5V directly to the Device connected (which will appear to the device like its coming from the OTG port) and with the SW change we make sure the Device uses this 5V supply and the Vbus will now be monitored by the device when the cable is connected
@Hakan Could you please elaborate more on your setup when you say "cut the red wire i.e. open the circuit on the PCB" - what do you mean exactly by this? Are you using a self powered hub and you have cut the 5V line which should go to the host?
And does this work with all high speed devices like Pen drives?
From: users-bounces at igloocommunity.org [mailto:users-bounces at igloocommunity.org] On Behalf Of Patrik KLINGER
Sent: Thursday, April 05, 2012 4:01 PM
To: Jacques Bride
Cc: Richard CURNOW; users at igloocommunity.org
Subject: Re: Problems with external 5V supply
Yes you will only need to perform what is in the wiki to implement a HW workaround.
In the wiki you will also see a reference to a software patch that need to be applied.
Snowball Program Manager
Office: +46 46 104525
Mobile: +46 768 433547
Email: patrik.klinger at stericsson.com<mailto:patrik.klinger at stericsson.com>
On 2012-04-05 12:19, Jacques Bride wrote:
Ok I better understand
My hub is already a 5V powered independent hub. Does it mean that I only have to apply the software change proposed in the wiki and that there is no need to do the hardware change in that case?
2012/4/5 Kalle Vahlman <kalle.vahlman at movial.com<mailto:kalle.vahlman at movial.com>>
Both hardware fixes in the wiki page take the 5V for the bus not from
the OTG port but directly from a power supply unit (either the one
powering the Snowball or the one powering a hub).
That's what Håkan suggested as well.
2012/4/5 Jacques Bride <jacques.bride at googlemail.com<mailto:jacques.bride at googlemail.com>>:
> Hello Patrik
> Thanks a lot for that wiki page, it will help many users.
> Anyhow, I am a bit confused. Your solution is more or less forcing 5V supply
> to the hub through OTG whereas the solution proposed by Håkan seems to do
> the opposite. I am not at all a hardware/electric specialist so sorry if my
> remark is nonsense and/or if I did not understand at all.
> Best regards
> 2012/4/4 Patrik Klinger <patrik.klinger at stericsson.com<mailto:patrik.klinger at stericsson.com>>
>> A wiki page has been created for the USB Host issue experienced on the
>> Snowball A9500.
>> Patrik Klinger
>> Snowball Program Manager
>> Office: +46 46 104525<tel:%2B46%2046%20104525>
>> Mobile: +46 768 433547<tel:%2B46%20768%20433547>
>> Email: patrik.klinger at stericsson.com<mailto:patrik.klinger at stericsson.com>
>> On 2012-04-04 05:51, Håkan Berg wrote:
>> Patrik: I have tried only USB2 devices. Mouse and keyboard direct and also
>> via dongle. I have also used an 8 GB memory-stick, and it worked fine as
>> well. So high-speed USB works, but I have not tried Ultra-Speed.
>> Jacques: Regarding OTG power detection, I suppose you are rigth. I
>> probably means that the detection somehow fails.
>> Since I heard something about wardware error causing the USB problems I
>> asked a guy at ST-Ericsson and got an explanation. The ground wiring for the
>> power and USB parts was not done properly on the Snowball, causing ground
>> level noise. This could have a huge impact when connecting and disconnecting
>> a cable at the OTG port if current goes in either direction of the +5V lead,
>> since that also means the same current goes through the ground lead.
>> Den 2 april 2012 17:00 skrev Richard Curnow
>> <richard.curnow at stericsson.com<mailto:richard.curnow at stericsson.com>>:
>>> Hi Kalle,
>>> On 04/02/2012 03:47 PM, Kalle Vahlman wrote:
>>>> But yes, there's a funny discrepancy on behavior with OTG power and
>>>> "wall power" wrt bootup, mainly due to flashing I guess.
>>> OK, that makes sense.
>>>> Another way to reset the board is to press the blue button for 10s
>>>> (yes, that long) to shut it down and then press it again to boot up.
>>> That works for me. Apart from the delay, I think it's preferable,
>>> because the switch feels a lot more resilient than the other one.
>>> users mailing list
>>> users at igloocommunity.org<mailto:users at igloocommunity.org>
> users mailing list
> users at igloocommunity.org<mailto:users at igloocommunity.org>
Kalle Vahlman, Movial Creative Technologies Inc.
Porkkalankatu 20, FI-00180 Helsinki
Tel +358 9 8567 6400<tel:%2B358%209%208567%206400>
Fax +358 9 8567 6401<tel:%2B358%209%208567%206401>
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the users