freerunner: charging and usb-host mutually exclusive?

joerg joerg.twinklephone at
Tue Mar 11 22:40:25 CET 2008

Am Di  11. März 2008 schrieb Andy Green:
> - gpg control packet
> Somebody in the thread at some point said:
> > No, I was just noting you could put the CPU peripheral logic into host
> > mode but leave the EN_USBHOST signal low.  Then you could add 15K
> > pulldowns as a hack, and it would all work.  But it is a bit of a mess
> > and would then only work in this externally powered host mode.
> Ha, actually that's not true, I just enabled EN_USBHOST, which does
> nothing about the CPU peripehral mode for USB right now -- but it does
> enable the 15K pulldowns -- and the thing still works as an Ethernet
> class device including insertion detection on the remote host.
> So if you added a pair of 15K pulldowns to D- and D+ yourself (there are
> testpoints), and took care to not enable EN_USBHOST but have the CPU
> peripheral in host mode, you should be good to go as an externally
> powered host, including charging, and the same setup can work on at
> least some hosts as a device, despite we pull down by 7.5K when the host
> pulldowns get in on the game as well.

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? ;-)

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

What's about this?

More information about the community mailing list