HopTalk 🚀

Offline Push-to-Talk Walkie-Talkie for Smartphones

HopTalk is a mobile app that transforms your smartphone into a real-time walkie-talkie using Wi-Fi Direct mesh networking — no internet required. Messages and voice hop device-to-device, extending your communication range. Perfect for outdoor adventures, events, or areas with no cellular coverage.

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🔹 Features

• Push-to-Talk (PTT) interface: Hold to speak, release to stop.
• Offline voice streaming: No internet or cellular data needed.
• Hop-by-hop forwarding: Extend communication range via nearby devices.
• Peer discovery: Automatic detection of nearby phones.
• Multi-hop mesh network: Reach distant peers using intermediate devices.
• Lightweight and real-time: Minimal latency for smooth conversation.

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🔹 How It Works

1. Phones connect via Wi-Fi Direct.
2. Voice is captured in small audio chunks and sent as UDP packets.
3. Each device can forward received packets to other peers (mesh/hop functionality).
4. Destination device plays the audio in real-time.

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🔹 Technology Stack

• Platform: Android
• Language: Kotlin / Java
• Audio: AudioRecord & AudioTrack APIs
• Networking: Wi-Fi Direct, UDP sockets
• Codec: PCM16 (future: Opus for compression)
• Architecture: Peer-to-peer mesh with hop forwarding

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🔹 Installation & Usage

1. Clone this repository:

   git clone https://github.com/<your-username>/HopTalk.git

2. Open in Android Studio.

3. Build & run on Android devices (minimum API 21).

4. Press Scan for Peers, connect to nearby devices.

5. Press PTT button to start talking!

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🔹 Roadmap / Next Steps

• ✅ Single-hop voice streaming prototype
• 🔜 Multi-hop mesh forwarding for extended range
• 🔜 Opus audio compression for bandwidth optimization
• 🔜 User-friendly UI & contact list
• 🔜 Optional: Message recording & offline storage

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🔹 License

HopTalk is MIT Licensed — free to use, modify, and share.

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🔹 Contact

Developed with 💡 by [Your Name] GitHub: https://github.com/