USB keyboard in hostmode?

Jay Vaughan jayv at
Tue Aug 19 14:10:50 CEST 2008

> 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.

Easiest way to get them: put a USB hub in between, and see if that  
makes things better.

Jay Vaughan

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