USB keyboard in hostmode?
openmoko at mazikeen.demon.co.uk
Wed Aug 20 16:49:20 CEST 2008
On Tuesday 19 August 2008, Jay Vaughan wrote:
> > Maybe i should test it with a more simple usb keyboard without any
> > extra
> > functions.
> You should test your USB keyboard with the Freerunner, using a USB
> *HUB* in between, and see if that doesn't fix things. IFAICT, there
> are details not-yet-well-understood regarding the nature of the
> termination and 'pull-up' resistor normally included on standard USB
> Host ports which may not be included with the Freerunner hardware
> design - meaning a simple female/female convertor isn't going to be
> enough, there will need to be a cap and a resistor included in the
> schematic in order to make the USB Host controller onboard the
> Freerunner believe it is talking to a proper USB hub node. If this
> isn't there, the controller believes its only got a single device to
> talk with, physically, and in your case this isn't true - you've got
> two devices onboard. So, you need the cap and resistor, I bet.
Do you have a source for this info? The only need for external components that
I'm aware of is the 15k pulldowns when charging while in host mode. This
information used to be in the wiki on the GTA02 Hardware page but has been
moved or removed. It's still in the history though:
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