I have been asked into looking for usb host support for nook touch. The hardware appears to be pretty similar to Nook Color, so there were no troubles in that area.
The kernel used by B&N for the Nook Touch is somewhat older than .32 kernel used for Nook Color, so the patch itself required some massage. Surprisingly B&N kernel already has usb host support compiled in, so you don't even need to change anything in kernel config, just apply the patch.
Just like in Nook Color, the id pin in the usb receptacle is not connected anywhere, so a special app is needed to switch the host mode on and off. The Nook Color usbhost switcher should work: https://github.com/verygreen/Nook-Co...bhost-switcher though I cannot compile it for eclair, so I guess that needs some more massage and help here would be appreciated.
Meanwhile you can simply switch the mode from adb, type
echo host > /sys/devices/platform/musb_hdrc/mode
echo peripheral > /sys/devices/platform/musb_hdrc/mode
The LED at the bottom that usually indicates charging status will light up in usb host mode even if the power is not connected.
The upside is you don't need a special OTG cable and can just use gender changer on your existing nook cable if you so desire.
- I have not tracked why yet, but self powered mode only works when you try to enable it first with external power plugged in first.
- The user-friendly tool for usbhost mode switching needs to be compiled for eclair
- The self-powered mode is very faint. Keeps up with my keyboard, but not even with a simple usb hub.
- Battery drain is significant, though not sure what part of it is attributed to the usbhost mode and what to adb over wifi
- Eclair init is buggy so input devices are unusable without a patch, see commit 6405c6953fa02d41d9f6377f4cdb947604f481c4 in google tree to sytem/core/init. I am attaching recompiled init binary that works.
Attachments: binary.zip contains:
- uImage - prebuilt 1.1 kernel with the patch
- uRamdisk - root ramdisk with fixed init, adb over wifi
- init - just recompiled init binary for those who might need it
andrewed, who asked me to do this and also provided me with a device. He is on a quest to touchtype on e-paper with a USB physical keyboard, all described here: Project: E-Paper Tablet (typable!)