BT Lights Widget Android

A home screen widget for setting colors of generic Bluetooth lights on Android. Is transparent except the preset colors.

Bluetooth Low Energy lights that accept characteristic 0x0009 (UUID 0000ffd9-0000-1000-8000-00805f9b34fb) value 56[red][green][blue]00f0aa are supported. Minimal implementation - see Configure below.

Build & install

Requirements:

• Java
• Android SDK

Get the source code

git clone https://github.com/alex-vt/BT-Lights-Widget-Android
cd BT-Lights-Widget-Android

Configure

In app/res/values/bluetooth_mac_addresses.xml, replace line 4 with one or more Bluetooth MAC addresses of supported lights, 1 per line. Example of a line with a MAC address 01:23:45:AB:CD:EF: <item>01:23:45:AB:CD:EF</item>

Optionally, also change the 6 color presets in app/res/values/colors.xml (keep the attribute names). A preset contains hexadecimal values of red, green and blue corresponding color component brightnesses, from 00 to ff. With all color component values 00, light can be considered off.

Supported lights can be tested with the gatttool Linux command line command. For a light with the example MAC address "01:23:45:AB:CD:EF" the commands for colors will be:

Color	Hexadecimal	gatttool example command
Light off	000000	gatttool -b 01:23:45:AB:CD:EF --char-write-req -a 0x0009 -n 5600000000f0aa
Red	ff0000	gatttool -b 01:23:45:AB:CD:EF --char-write-req -a 0x0009 -n 56ff000000f0aa
Green	00ff00	gatttool -b 01:23:45:AB:CD:EF --char-write-req -a 0x0009 -n 5600ff0000f0aa
Blue	0000ff	gatttool -b 01:23:45:AB:CD:EF --char-write-req -a 0x0009 -n 560000ff00f0aa
White	ffffff	gatttool -b 01:23:45:AB:CD:EF --char-write-req -a 0x0009 -n 56ffffff00f0aa

Also, optionally, padding on all sides of the widget can be adjusted in app/res/layout/widget_layout.xml lines 10..13 for fine alignment of the widget on home screen.

App signing setup

• Put your keystore.jks to the project's root folder for signing the app.
• Create a signing.properties in the project's root folder with keystore.jks credentials:

signingStoreLocation=../keystore.jks
signingStorePassword=<keystore.jks password>
signingKeyAlias=<keystore.jks alias>
signingKeyPassword=<keystore.jks key password>

Install on ADB connected device:

./gradlew app:installRelease

Build installable APK

./gradlew app:assembleRelease

Then install app/build/outputs/apk/release/app-release.apk on Android device.

Once installed, 2x1 sized BT Lights Widget is available in the list of widgets to put on home screen.

License

MIT license.