freerunner: charging and usb-host mutually exclusive?

Andy Green andy at
Tue Mar 11 23:09:00 CET 2008

Hash: SHA1

Somebody in the thread at some point said:

> Ah, i see a Y-adapter: one end usb-device, one end receptable for usb charger, 
> one end GTA02 *with ID-R of e.g 82k* PLUS *2 x 15k pulldown*.
> And GTA02 automatically switching to external powered host mode. :-)
> This was on the list of accessories from the beginning, wasn't it? ;-)

Yes it sounds like a good solution, it probably doesn't make trouble to
have 7.5K pulldown total in device mode either.  I dunno if Openmoko are
interested to make it but anyone that wants host with external charging
power can hack it up from their spare cable box without opening the
phone, that is miles ahead of where we were a couple of hours ago.

> humm, on 2nd thought, nothing bad will happen when this mode will check for 
> 47k instead of 82k.

Yes we need to react to seeing the 1A charger ID resistor by deasserting
EN_USBHOST for sure, that is right if it is just the charger or it is
the external power host mode adapter.  We didn't take care about it
until now, I will make a patch.

> What's about this?


- -Andy
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