Android USB Deploy

Overview

Builds an Android app using Gradle and installs it directly to a USB-connected Android device via ADB (Android Debug Bridge). This is the fastest way to test on real hardware during development.

When to Use

Invoke this skill when the user:

• Asks to "deploy to Android"
• Wants to "install the app on device"
• Says "build and deploy Android"
• Mentions testing on physical Android device
• Wants to "push to device"

Prerequisites

• Android device connected via USB
• USB Debugging enabled (Settings → System → Developer options → USB debugging)
• Developer Mode enabled (Settings → About Phone → tap Build number 7 times)
• ADB installed (brew install android-platform-tools on macOS)
• Device authorized for debugging (RSA key accepted)
• JAVA_HOME must be set: export JAVA_HOME="/opt/homebrew/opt/openjdk"

Instructions

1. Navigate to the Android app directory (look for build.gradle.kts):

   cd path/to/android/app
   

2. Set JAVA_HOME environment variable:

   export JAVA_HOME="/opt/homebrew/opt/openjdk"
   

3. Run the install-device.sh script:

   ./install-device.sh
   

4. The script will:

   • Check if device is connected via adb devices
   • Build the APK with ./gradlew assembleDebug
   • Install with adb install -r app/build/outputs/apk/debug/app-debug.apk
   • Launch the app with adb shell am start

5. Inform the user:

   • Initial build may take longer (~10-30 seconds)
   • Subsequent builds are faster (~2-5 seconds)
   • App will launch automatically on device
   • Check device screen to see the app running

Expected Output

📱 Installing NoobTest to connected device...
✅ Found device: ABC123XYZ
🔨 Building...
✅ Build complete
📲 Installing...
✅ Installation complete
🚀 Launching app...
🎉 App installed and launched!

How It Works

The deployment process:

1. Check device: adb devices confirms connection
2. Build APK: ./gradlew assembleDebug compiles the app
3. Install: adb install -r (replace existing installation)
4. Launch: adb shell am start -n com.miso.noobtest/.MainActivity

Common Issues

"no devices found":

• Enable USB debugging in Developer Options
• Accept RSA authorization prompt on device
• Try: adb kill-server && adb start-server
• Check USB cable supports data (not just charging)

"Unable to locate a Java Runtime":

• Set JAVA_HOME: export JAVA_HOME="/opt/homebrew/opt/openjdk"
• Verify: echo $JAVA_HOME
• Install OpenJDK if missing: brew install openjdk

"INSTALL_FAILED_UPDATE_INCOMPATIBLE":

• App signatures don't match existing installation
• Uninstall first: adb uninstall com.miso.noobtest
• Try installation again

"device unauthorized":

• Check device screen for RSA key authorization prompt
• Accept the authorization
• Replug device and try again

"adb: command not found":

• Install Android platform tools: brew install android-platform-tools

Build Speed

• First build: ~10-30 seconds (downloads dependencies)
• Incremental builds: ~2-5 seconds
• Much faster than iOS due to Gradle's incremental compilation

Package Name

The script is configured for the specific app's package name (e.g., com.miso.noobtest for Firefly/NoobTest). Different apps have different package names configured in build.gradle.kts.

Gradle Note

Always set JAVA_HOME before running Gradle commands. This is a critical requirement on macOS with Homebrew-installed Java.