Connect USB devices to your Nexus One

• Required hardware
  • Rooted Nexus One (Desire/Incredible port)
  • Micro USB OTG cable (e.g., advantage: ID pin connected to ground for future auto detection) or Micro USB cable and adapter
  • Powered USB 2.0 hub. Hubs known to provide their power to the upstream port:
    • TiVECO TM-UH710
    • Trust HU-5870V
  • If your hub doesn't provide its power to the upstream port (the Nexus One isn't charged): USB Dual Power Cable (e.g.), since the Nexus One doesn't provide bus power to the hub chip
  • For mobile use: battery (e.g.) (measurements)
• Software based on Android 2.2 Froyo FRF91
  • Download binaries…
    • boot.img or zImage
    • Modules (Mind /system/lib/modules/bcm4329.ko!)
  • …or build from source
    
    • git clone git://android.git.kernel.org/kernel/msm.git
      cd msm
      git checkout origin/android-msm-2.6.32
      wget http://sven.killig.de/android/N1/2.2/usb_host/.config
      patch -p1 < android-kernel_msm-3c98b0d_Nexus-One_usb-host.patch
      make -j2 ARCH=arm CROSS_COMPILE=/android-ndk-r4b/build/prebuilt/linux-x86/arm-eabi-4.4.0/bin/arm-eabi-
  • Install kernel
    • Boot from RAM (till next reset)…
      • /android-sdk-linux_86/tools/fastboot boot arch/arm/boot/zImage
        
    • …or write to flash (boot.img from your nandroid backup)
      • /getramdisk.py /boot.img
        /android-sdk-linux_86/tools/fastboot -b 0x20000000 flash:raw boot arch/arm/boot/zImage ramdisk.img
        
  • Start ConnectBot, enable full screen and connect to Local
    • su
      insmod drivers/usb/core/usbcore.ko
      # Ignore the Unbalanced enabled for IRQ 58 stack trace for now
      insmod drivers/usb/host/ehci-hcd.ko
  • Substitute device mode over TCP/IP (or port Andrew de Quincey's work)
    • adb
      • adb connect IP_address:5555
    • Filesystem access
      • Nexus One's
        • On Air (Vista/7 WebDAV registry patch, ro)
        • nandroid
      • PC's
        • insmod fs/cifs/cifs.ko
          mount -t cifs -o username="username",password="password" //IP_address/share /mnt/sdcard/cifs

HID input devices

• insmod drivers/hid/usbhid/usbhid.ko
• X11
  • /etc/X11/xorg.conf
  • apt-get install lxde
    startx
    

USB storage

• insmod drivers/usb/storage/usb-storage.ko
  # Wait for device enumeration
  mount -t vfat /dev/block/sda1 /mnt/sdcard/usb-storage

Ethernet

• insmod drivers/net/usb/usbnet.ko
  insmod drivers/net/usb/asix.ko
  dhcpcd eth1
  setprop net.dns1 IP_address

External displays

• Hardware
  • DisplayLink device
• Software
  • SlugTerm DL
    • mount -t usbfs none /proc/bus/usb
      /data/local/bin/slugterm -k /dev/input/event8 -p 0377 -i 00cfa43c4e5573712b7152ffffeeca0640e257fffffff904b00402907e -f /mnt/sdcard/usr/local/share/fonts/FON2FNT/dosapp_18.FNT -c /system/bin/sh
  • Framebuffer
    • insmod drivers/video/syscopyarea.ko
      insmod drivers/video/sysfillrect.ko
      insmod drivers/video/sysimgblt.ko
      insmod drivers/video/fb_sys_fops.ko
      # Source+xf86Crtc.h; disable CONFIG_FB_DEFERRED_IO
      insmod drivers/staging/udlfb/udlfb.ko
      # Wait for device enumeration
    • Android framework
      • chmod 666 /dev/graphics/fb1
      • /system/build.prop:
        dalvik.vm.heapsize=42m
      • Framebuffer fb=new Framebuffer(1);
        Bitmap bm=fb.createBitmap();
        fb.tranfer(bm, true);
        
      • Also included: Display images on a DisplayLink device from all Android apps through SEND Intent:

        

    • Console (Warning: once it scrolled, Nexus One won't shutdown completely)
      • insmod drivers/video/console/font.ko
        insmod drivers/video/console/softcursor.ko
        insmod drivers/video/console/bitblit.ko
        insmod drivers/video/console/fbcon.ko
      • Android framework
        • chmod 666 /dev/console
        • PrintWriter pw=new PrintWriter("/dev/console");
          pw.println("Hello Android!");
    • X11
      • Lenny
        • /etc/X11/xorg.conf
        • /usr/local/lib/xorg/modules/drivers/displaylink_drv.so (Source)
      • Squeeze
        • /etc/X11/xorg.conf
        • /usr/local/lib/xorg/modules/drivers/fbdev_drv.so (Source)
    • As primary display (BeagleBoard)

Audio/MIDI devices

• insmod sound/soundcore.ko
  insmod sound/core/snd.ko
  insmod sound/core/snd-timer.ko
  insmod sound/core/snd-hrtimer.ko
  insmod sound/core/snd-page-alloc.ko
  insmod sound/core/snd-pcm.ko
  insmod sound/core/snd-rawmidi.ko
  insmod sound/core/snd-hwdep.ko
  insmod sound/usb/snd-usb-lib.ko
  insmod sound/usb/snd-usb-audio.ko
• Android framework
  • insmod sound/core/oss/snd-mixer-oss.ko
    insmod sound/core/oss/snd-pcm-oss.ko
    chmod 666 /dev/snd/dsp
  • FileInput/OutputStream("/dev/snd/dsp")

TV Receivers

• Hardware
  • Receiver (e.g. DVB-T)
  • ALSA Audio device
• Software
  • mplayer scripts (720×480: ~25 FPS)
  • Refresh DisplayLink device periodically (Source) (720×288: some FPS)
• Ideas to enable deinterlacing and scaling
  • MSM/QSD X-Window Enablement Project including XVideo
  • OpenMAX (seems to be supported by VLC 1.1)
  • Android native SurfaceFlinger output plugin

Thread @ xda-developers