power plug

Sergio Bessa sergio.bessa at ideavity.com
Sat Jan 20 18:50:49 CET 2007


Andreas Kostyrka wrote:
> * Nikita V. Youshchenko <yoush at debian.org> [070120 13:19]:
>   
>>>> How can it charge over USB if it gets full discharged?
>>>> AFAIK, USB device is not powered by USB host until it is configured.
>>>> So gadged must be operational to charge over usb.
>>>>         
>>> Well, I'm almost certain that my USB mouse has no battery builtin, so
>>> I guess USB does provide some minimal power to enable configuration.
>>>       
>> Sure.
>> That depends on how usb client hardware is done.
>> In your mouse, there is microcontroller that controls usb client
>> functionality, and powers itself from usb (yes usb gives some limited
>> power - up to 100 mA if I remember correctly - even to client which is not
>> configured yet.
>>
>> But in case when USB is controlled by Linux USB Gadget driver, central CPU
>> must be operational and kernel up and running for USB client functionality
>> to work.
>>     
> That depends upon how clever the USB port hardware is, I'd guess.
>
>   
>> Soft is Linux kernel in my case.
>> And yes, it can't charge over usb until it is up.
>>     
> I know, I've owned an iPaq with GPE once with that characteristic too ;)
>   
My Motorola V3 had the same problem... I could not let it 'die' or I 
would need to use the power outlet adapter to charge it :S
It was a very annoying feature, speccially while traveling... it's a lot 
easier to carry a mini usb cable than the adapter and the cable can be 
used for many other things, from web cams to IP phones etc...

Sergio Bessa
> Andreas
>
> _______________________________________________
> OpenMoko community mailing list
> community at lists.openmoko.org
> https://lists.openmoko.org/mailman/listinfo/community
>   

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.openmoko.org/pipermail/community/attachments/20070120/404cdbaa/attachment.htm 


More information about the community mailing list