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I'm trying to do a little key remapping in Android 5.1 by creating custom keylayout files for my Bluetooth devices, however a few of my devices have keys that either don't do anything in Android (such as iOS specific keys on a keyboard) or get intercepted by Android before it shows up as a key event.

As far as I can tell, the issue is that these keys have scancodes that don't currently map to anything in the generic keylayout list, or they're considered a system key like the Home key and the actual key press never reaches regular apps. Assuming it's because the scancode doesn't map to anything yet in Android, is there any way to get the raw scancodes coming in from the device so I can try to document the codes myself and write a proper keylayout file for it? I have root on my device and I can also connect the devices to my Windows 10 PC if there's a Windows based method to read unknown scancodes from a Bluetooth keyboard.

Ceetch
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1 Answers1

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I know this is an old question but I ran across it while looking for something similar.

There might be a better way to do this but this is the only way I know how to change the keycodes you need root.

first connect your bluetooth device to your android device and then your android device to your pc. In command prompt type: 

adb shell
cat /proc/bus/input/devices

it'll print out something similar to this 

I: Bus=0005 Vendor=0b05 Product=4500 Version=0031
N: Name="ASUS Gamepad"

there will be more than this and for many more devices but we're gonna use the asus game pad for instance. On your desktop make a text file called Vendor_0b05_Product_4500.kl it's case sensitive so make sure the v+p are both upper case.

Install the apk cde recommended or get the open source version here https://github.com/chrisboyle/keytest/downloads install it run it and press the key(s) you want to remap. Both apps will show you the scan codes write them down and the key that they are mapped to.

Now you have all the scan codes open up the Vendor_0b05_Product_4500.kl in a text editor and type this for instance 

#Asus Gamepad
#key 304 BUTTON_A

the key 304 is the scancode and the BUTTON_A is the keycode you want the android system to interpret it as.

Save the file and adb push it to /system/usr/keylayout/ and reboot your device if you need help with the keycodes look here http://developer.android.com/reference/android/view/KeyEvent.html just don't add the KEYCODE part.

asadullah
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