GTA02 USB and battery current profile

[Felipe Balbi]

On Sun, Mar 09, 2008 at 10:56:37AM -0300, Werner Almesberger wrote:
> Felipe Balbi wrote:
> > But you're misusing id pin. This is a huge hardware issue and should be
> > solve asap. Id pin should generate an interrupt to the otg transceiver
> > for it to switch between host and peripheral roles.
> 
> I don't know much about OTG, but our documentation says that OTG gives
> us either ID open or ID very low-ohm, so we should be able to detect
> that resistor "in the middle", no ?

True, although i don't like the idea of using id pin for detecting
chargers. In any case, if it works...

> > Instead of hardcoding 500mA current draw in the config descriptors, you
> > should add 2 sets of them:
> > 1. drawing 500mA
> > 2. drawing 100mA
> 
> Hmm, that's what we usually do. I'll check later if we're also
> consistent there.

What i could see is there's only one set of descriptors set to 500mA,
that would break if I try to attach neo to my n810. That only config
descriptor would be rejected.

Just passed through my mind this idea, it would be nice to popup the
user about which module to use, like when you attach an Nseries nokia
phone to your pc, it asks "Pc-suite, Data transfer". How about that ?

We ask the user and we change the module from g_file_storage to g_ether
and stuff. :-)

> > BTW, really precise resistor you got:-p
> > 1% tolerance, wow. That must be kinda difficult to find :-p
> 
> Hmm, now that you mention it, 48k is indeed hard to find. Gotta check
> what it really is - maybe plain good old 47k. That would be available
> even with +/-0.1% accuracy :)

Good :-)

-- 
Best Regards,

Felipe Balbi
me at felipebalbi.com
http://blog.felipebalbi.com