This is a template of a Java/Gradle-based Android application for controlling an Estimote BLE-based location beacon deployment. See also the documentation for the Android SDK.
Several beacons are deployed, each in a virtual room: we want to locate the closest one with respect to our control device, i.e. an Android-based smartphone.
Each beacon is univocally identified by a pair: major and minor numerical IDs. Beacons come in pairs, each sharing the same major ID.
Our goal is to write code based on the Fleet Management API to locate, given a major ID, the beacon closest to us and show that ID on the app main screen (in lieu of "RoomX"), as shown below (ignore all other widgets, they're not involved in this exercise):
Keep in mind that your app must be granted access to Android's Location service, and, of course, Bluetooth must be on.
Other apps that might help you with BLE appliances are:
You need to install the following mandatory packages on your development workstation (follow your GNU/Linux distribution's instructions -- package names below are for Arch Linux):
- Java Development Kit v8 (avoid newer releases) of your choice, f.i.:
jdk-openjdk - Build system for the JVM:
gradle - Android SDK:
android-sdk - Android platform tools:
android-tools
and, optionally:
- Official Android ID:
android-studio - Google Android Emulator:
android-emulator
In order to connect your Android device to your development workstation via
adb, you might need to install some auxiliary packages and/or tweak some
udev rules. In Arch Linux, this done by the android-udev
package.
Run this at your shell or put it in your ~/.bashrc (change
/path/to/your/sdk with the real installation path -- /opt/android-sdk on
Arch Linux)
ANDROID_SDK_ROOT=/path/to/your/sdk
ANDROID_HOME=$ANDROID_SDK_ROOT
PATH="${ANDROID_HOME}/tools/bin${PATH:+:${PATH}}"
export ANDROID_SDK_ROOT ANDROID_HOME PATH
Accept the SDK licenses. If your SDK is user-installed, run
$ yes | sdkmanager --licenses
else (system install)
$ yes | sudo sdkmanager --licenses
If your SDK is installed system-wide, you need to manually install some components -- else, you'll get errors like "The SDK directory is not writable (/opt/android-sdk)":
$ sudo sdkmanager --install "platforms;android-26" "build-tools;27.0.3" "platform-tools"
The only file to be modified for this lab is
app/src/main/java/com/example/iot_hes/iotlab/MainActivity.java
Please note, this is a symlink to MainActivity.java.incomplete -- you
shouldn't change it. In case of problems with that, rename
MainActivity.java.incomplete to MainActivity.java.
Inside your project directory, run the following command:
$ ./gradlew build
Results are in app/build/outputs/apk/. You can now install the debug version via the command:
$ ./gradlew installDebug
Please note that, the release app must be signed. Then you'll be able to install it with:
$ adb install app/build/outputs/apk/release/app-release.apk
After any changes to the code, prior to rebuild, you better off to run:
$ ./gradlew cleanBuildCache clean
then rebuild the app.
This section is for code maintainers. Students are however encouraged to read :-)
Most tasks are available via the included Makefile. See:
$ make help