HyTalkPTT is an Android application that enables a configurable physical PTT (Push-To-Talk) button to activate the HyTalk application. It works with Motorola LEX F10, UROVO DT30, Ulefone, and other devices whose PTT keycode you configure in the app. External Bluetooth PTT microphones are supported as well — for example Inrico BT02 and similar headsets that deliver PTT over Bluetooth (HFP vendor / AVRCP / media keys, depending on the device).

The app intercepts PTT button presses and converts them into broadcast intents that HyTalk recognizes. It uses an Accessibility Service to capture global key events and sends android.intent.action.PTT_DOWN and android.intent.action.PTT_UP broadcasts. The PTT keycode is stored in app preferences (default 228 for Motorola LEX F10) and can be changed via Configure PTT Key in the app.

Setup order matters: enable Accessibility for HyTalkPTT first (otherwise key events are not delivered to the app), then Configure PTT Key, then optional Configure Programmable Keys (for Motorola) on supported devices.

• Devices: Motorola LEX F10 (default keycode 228), UROVO DT30, Ulefone (26WT, 20WT, 18T, etc.), or any device with a configurable PTT keycode; external Bluetooth PTT mics (e.g. Inrico BT02 and similar) when the phone exposes their PTT to apps (see below)
• Android: Android 5.1.1 (API 22)
• Target app: HyTalk (com.hytera.ocean / com.hytalkpro.ocean where applicable)
• Android Studio: Latest with Android SDK

• Accessibility-based capture: Global PTT handling requires HyTalkPTT to be enabled under Settings → Accessibility before keys are intercepted.
• Configurable PTT keycode: Set via Configure PTT Key (press your hardware PTT → Save). Default 228 (Motorola LEX F10).
• Intercepts only the configured PTT key and converts it to broadcast intents for HyTalk
• Bluetooth PTT (optional): external mics and headsets — HFP hook, AVRCP media keys, and HFP vendor-specific events (used by devices such as Inrico BT02). Enable Bluetooth headset / microphone PTT in Configure PTT Key and tap Save settings.
• Automatically launches or brings HyTalk to foreground when PTT is pressed
• Works when the app is in the background or was killed
• Minimal resource usage

Configure these steps in this order:

1. Open HyTalkPTT from the launcher.
2. Tap Configure Accessibility (first button on the main screen).
3. In Settings → Accessibility, find HyTalkPTT and enable the service.

Without this step, the app cannot receive global PTT key events.

1. Return to HyTalkPTT and tap Configure PTT Key.
2. Press your device’s physical PTT button (or configure Bluetooth PTT sources as needed).
3. Tap Save settings.

The app stores the keycode (e.g. 228 for LEX F10, 520–522 for UROVO DT30, 381/301/131 for Ulefone). You can change it anytime by repeating these steps.

1. In HyTalkPTT, tap Configure Programmable Keys (for Motorola) (opens system Settings).
2. Go to Settings → Programmable Keys (path may vary by device).
3. Set PTT Key app (or equivalent) to HyTalkPTT.

This helps the device deliver PTT events when locked or in the background (where supported).

Support has been added for external Bluetooth PTT microphones that work like a dedicated radio-style PTT button over Bluetooth. Examples include Inrico BT02 and similar models from Inrico or other vendors, provided the Android Bluetooth stack forwards their events to apps.

• In Configure PTT Key, enable Bluetooth headset / microphone PTT and Save settings (until you save, Bluetooth capture is not active).
• Some radios (e.g. Retevis / Ailunce HD2 over Bluetooth) send PLAY/PAUSE as a very short pulse (DOWN+UP in a few milliseconds), so HyTalk only sees a “click”, not a hold. Enable Tap to toggle transmit in Configure PTT Key: first tap = start PTT, second tap = stop (no periodic PTT_DOWN in toggle mode; normal press-to-talk over Bluetooth still uses keepalive while the key is held). Leave toggle off for headsets that send a real key hold.
• Depending on the mic, PTT may arrive as AVRCP (play/pause), HFP hook, or vendor-specific HFP frames (e.g. +XEVENT / TALK press and release). The app maps these to the same PTT_DOWN / PTT_UP broadcasts as the hardware key.
• If nothing appears when you press PTT, the device may use a proprietary protocol that Android does not expose — in that case use the phone’s own programmable PTT key or another mic model.

Debug / proximity on HD2 (and similar): the app logs Bluetooth probe lines with tag HyTalkPTT-BtProbe (vendor HFP VENDOR_SPECIFIC, MEDIA_BUTTON extras, and KeyEvent from MediaSession vs accessibility). Capture while touching the sensor:

adb logcat -v time 'HyTalkPTT-BtProbe:I' 'PTTAccessibilityService:D' '*:S'

(Quote *:S in zsh.) Compare finger-on vs finger-off lines; vendor AT commands may use a different company id than 85 — the action-only vendor receiver logs those without the category filter.

If you hear a short tone in the earpiece when touching a proximity sensor but no HyTalkPTT-BtProbe lines appear, the headset is almost certainly handling the sensor inside its own firmware (local audio feedback only). Android apps then receive no separate key or vendor event for that gesture — HyTalkPTT cannot map it unless the manufacturer exposes a documented Bluetooth command stream.

• Android Studio (latest)
• Android SDK API 22 (compile SDK is intentionally 22 for legacy device support)
• JDK 8+

1. Clone the repo:

   git clone https://github.com/chepil/HyTalkPTT.git
   cd HyTalkPTT

2. Open the project in Android Studio and sync Gradle.

3. Build and install:

   ./gradlew installDebug

   Or: Build → Make Project, then Run → Run 'app' with the device connected via USB (USB debugging enabled).

./gradlew installDebug          # build and install debug APK
./gradlew assembleRelease       # release APK → app/build/outputs/apk/release/
./gradlew clean
./gradlew lint                  # fails on NewApi / incompatible API use

Release APK naming pattern: HyTalkPTT-v{versionName}-{versionCode}.apk (see app/build.gradle).

Hardware PTT (and/or Bluetooth media keys)
         ↓
PTTAccessibilityService.onKeyEvent() / MEDIA_BUTTON receiver  ← Accessibility + MediaSession
         ↓
    ├─ Broadcast: PTT_DOWN / PTT_UP → HyTalk (com.hytera.ocean, …)
    └─ startActivity when PTT pressed — bring HyTalk to foreground

1. Accessibility: PTTAccessibilityService must be enabled so the system can deliver filtered key events (android:canRequestFilterKeyEvents="true").

2. Configured PTT keycode: Stored in SharedPreferences (prefs name ru.chepil.hytalkptt.ptt_prefs, key ptt_keycode; default 228). Set in Configure PTT Key.

3. Key paths: Global KeyEvents for the configured hardware key; Bluetooth via MediaSession, legacy registerMediaButtonEventReceiver, and vendor HFP where supported.

4. Broadcast intents: ACTION_DOWN → android.intent.action.PTT_DOWN; ACTION_UP → android.intent.action.PTT_UP (explicit package when resolved).

5. MainActivity ↔ service: static volatile MainActivity.isPTTButtonPressed for launcher / PTT flow coordination.

6. HyTalk listens for these broadcasts; the app launches or raises HyTalk when PTT is pressed.

• minSdkVersion / compileSdkVersion: 22 (Android 5.1.1). targetSdkVersion: 36. Java: 8.
• UI: No AndroidX — appcompat-v7:22.2.1 (version must match compile SDK).
• MainActivity: android:launchMode="singleTask".
• Package: ru.chepil.hytalkptt

The project is tuned for older rugged devices (e.g. LEX F10 on 5.1.1). Do not raise compileSdkVersion, minSdkVersion, or appcompat-v7 without testing on real hardware.

After dependency changes:

./gradlew dependencies --write-locks
./gradlew clean assembleRelease
./gradlew lint

See .github/compatibility-baseline.yml for the documented baseline.

• BIND_ACCESSIBILITY_SERVICE: For intercepting key events.
• BLUETOOTH: Declared so some OEM Bluetooth stacks deliver headset-related broadcasts.
• SYSTEM_ALERT_WINDOW: Optional, not used currently.

1. Enable Accessibility for HyTalkPTT (Configure Accessibility on the main screen).
2. Set Configure PTT Key (press PTT, enable Bluetooth PTT if needed, then Save).
3. On Motorola-type devices, use Configure Programmable Keys (for Motorola) and set PTT Key app → HyTalkPTT.
4. Check logcat:

   adb logcat | grep -i "HyTalkPTT\|PTTAccessibilityService"

One-screen timeline (accessibility + Bluetooth + broadcasts):

adb logcat -s HyTalkPTT-PTTTrace:I HyTalkPTT-MediaBtn:I PTTAccessibilityService:D MainActivity:D

Reproduce your issue (e.g. cold-start HyTalk → PTT on → PTT off). You should see broadcast PTT_DOWN / PTT_UP when the app sends intents.

• onKeyEvent SAVED_PTT_KEY … willHandle=false: the physical key reached the accessibility service but is ignored (e.g. only Bluetooth source enabled in settings).
• No SAVED_PTT_KEY while pressing the side PTT: Android did not deliver that keycode (foreground app / OEM); Bluetooth may still appear as HyTalkPTT-MediaBtn / dispatchBluetoothMediaKey.
• UP missing while Bluetooth toggle: HyTalk in foreground often steals AVRCP until routing is reclaimed; see service logs for reclaim AVRCP routing if using tap-to-toggle.

1. Install HyTalk (com.hytera.ocean or your build’s package).
2. Check logcat for launch errors.

• Open Configure PTT Key, press your PTT, confirm the shown keycode, then Save settings.
• On some devices, PTT may use different keycodes (e.g. 520, 521, 522 for UROVO DT30).

• The PTT setup screen uses a dark background; checkboxes use an explicit light tint so they stay visible. If anything is still unclear, use system Display settings or increase brightness.

The MIT License

Contributions are welcome! Please feel free to submit a Pull Request.

Denis Chepil — [email protected]

• Motorola LEX F10 (default keycode 228)
• UROVO DT30 (keycodes 520, 521, 522)
• Ulefone Armor 26 WT, 20 WT, 18T (e.g. 381, 301, 131)
• Inrico BT02 (Bluetooth PTT via HFP vendor / +XEVENT); other similar Bluetooth PTT mics may work if the OS delivers comparable events