ADB Watchdog (Android)

On-device watchdog for wireless ADB on Realme Narzo 50 (ColorOS). Polls Settings.Global.adb_wifi_enabled; when it goes to 0, tries to flip it back to 1 via the secure-settings path, and falls back to an AccessibilityService that drives the Settings UI if the flag write isn't honored.

Why two recovery paths

The primary path writes Settings.Global.adb_wifi_enabled = 1 directly. It requires WRITE_SECURE_SETTINGS which a normal app cannot request through the runtime-permission dialog — it must be granted once via ADB:

adb shell pm grant com.luffy.adbwatchdog android.permission.WRITE_SECURE_SETTINGS

This persists across reboots. After that, recovery is instant and silent.

On some ColorOS builds the flag write is accepted but AdbService ignores it (no observable side effect). The AccessibilityService is the fallback for that case: it opens Developer Options via intent, finds the "Wireless debugging" row, and toggles the switch. Slower (~3–5s), no permission grant needed, but fragile against Settings UI changes.

Build

Requires JDK 17 and Android SDK 34. From this directory:

# If you don't have the gradle wrapper yet:
gradle wrapper --gradle-version 8.7

./gradlew :app:assembleDebug
adb install -r app/build/outputs/apk/debug/app-debug.apk

Or just open the directory in Android Studio and let it import.

One-time setup on the phone

1. Install the APK.

2. Open ADB Watchdog, flip "Watchdog enabled".

3. Tap Open Accessibility settings → enable ADB Watchdog (UI fallback). (Skip this only if you're confident WRITE_SECURE_SETTINGS will work — but keep it as a safety net.)

4. Tap Disable battery optimization → choose "Don't optimize". Required — ColorOS will kill the foreground service otherwise.

5. From your PC, with USB ADB connected once:

   adb shell pm grant com.luffy.adbwatchdog android.permission.WRITE_SECURE_SETTINGS

6. Tap Test recovery now. The status panel should show Wireless ADB: ON and the recovery counter should tick up.

ColorOS keepalive checklist

ColorOS aggressively kills background services. Do all of these or the watchdog will silently die:

• Settings → Battery → ADB Watchdog → Allow background activity (or whatever ColorOS calls it on your build) → enable.
• Settings → Battery → ADB Watchdog → Auto-launch → enable.
• Phone Manager → Privacy permissions → Startup manager → allow ADB Watchdog.
• In Recents, swipe down on the ADB Watchdog card to lock it. Survives "clear all".

If the foreground notification disappears, the OS killed the service. Re-open the app to restart it.

What it does NOT do

• It does not re-pair an ADB host. Pairing persists on the phone side; once wireless ADB is re-enabled, a host that was previously paired and is on the same Wi-Fi can adb connect <phone-ip>:<port> again. The port is randomized per session on Android 11+ — you may want mDNS discovery (adb mdns services) on the host side.
• It does not unlock a PIN/pattern/password lockscreen. This phone is swipe-only per the spec.
• It does not survive a factory reset (you'd need to re-grant WRITE_SECURE_SETTINGS).

File layout

app/src/main/
├── AndroidManifest.xml
├── kotlin/com/luffy/adbwatchdog/
│   ├── AdbWifiController.kt      # read/write the secure setting + dispatch fallback
│   ├── WatchdogService.kt        # foreground service with poll loop
│   ├── WatchdogAccessibilityService.kt  # UI fallback
│   ├── BootReceiver.kt           # restart on boot if enabled
│   └── MainActivity.kt           # status UI + toggle
└── res/
    ├── layout/activity_main.xml
    ├── values/{strings,themes}.xml
    └── xml/accessibility_service_config.xml