📱System Requirements
DroidStar 9M2PJU runs on modern Android devices. No root access required.
🔧Our Modifications
This is a modified build of Doug McLain's DroidStar, customized by 9M2PJU. The core engine and all protocols are kept in sync with upstream. Our changes focus on branding, visual polish, and Android-specific fixes:
- Ham Radio Navy theme: deep navy (#0f1923) background with teal (#41cad2) accent matching the 9M2PJU logo. Tab bar with active indicator, card-based layout grouping on Main tab.
- 9M2PJU branding: app name, icon, splash screen, and About page customized with 9M2PJU identity and website link.
- About page: 9M2PJU logo, build info, website link, donation buttons (Buy Me a Coffee & Wise), and a Check for Updates button.
- Built-in vocoders: AMBE, Codec 2, and IMBE vocoders compiled directly into the APK. No external vocoder plugin download needed.
- Android 15 fix: safe area handling for edge-to-edge mode so the PTT button and navigation are never hidden behind the system nav bar.
- PTT button: large cyan rounded button that fills available space, turns dark red when transmitting. Press-and-hold to transmit, or enable TX toggle mode in Settings.
- Portrait orientation: app locked to portrait mode for a consistent layout.
- Release-signed APK: all builds are signed with a persistent release key, so you can update to new versions without uninstalling (no settings loss).
- Custom app icon & splash: 9M2PJU logo with navy background on launcher icon and splash screen.
- GitHub Actions CI: automated APK builds on every release tag.
- Crash-proof error handling: comprehensive null pointer guards across all modes (DMR, M17, YSF, P25, NXDN). The app never exits on unexpected errors - it shows a user-friendly popup instead.
- DMR connection retry & timeout: 3 retry attempts with timeout when connecting to a DMR master. Clear error popups for server rejection (MSTNAK), server shutdown (MSTCL), DNS failures, and unreachable hosts.
- In-app update checker: check for new versions from the About tab. Downloads and installs the latest APK with one tap.
📝Credits & License
Original DroidStar by Doug McLain AD8DP. Modified and distributed by 9M2PJU.
- Upstream: github.com/nostar/droidstar
- License: GPL v3.0
- Built with Qt 6.7.2 + NDK 27
Features
Multiple Modes
DMR, M17, YSF, P25, NXDN plus DCS / XRF / REF / FCS / IAX reflectors.
Built-in Vocoders
AMBE, Codec 2 & IMBE compiled in - no external plugin download required.
USB Vocoder Support
Connect an external AMBE vocoder or MMDVM modem over USB serial.
Operator Info
Auto-fetches handle & country from DMR ID via the Radioid API.
Ham Radio Navy Theme
Deep navy + teal accent matching the 9M2PJU logo. Card-based layout with visual grouping.
SMS & DTMF
M17 SMS messaging and IAX DTMF tone sending built in.
Screenshots
Tap a tab to view - tap the image for full size
💕 Support the Project
DroidStar 9M2PJU is free and open source. If you find it useful, consider buying us a coffee. Every contribution helps keep the builds coming.
How to Install
- Download the APK file using the button above.
- On your Android phone, open Settings → Apps → Special access → Install unknown apps (or "Install unknown apps" for your browser/file manager) and allow it.
- Tap the downloaded .apk file in your Files app or notification.
- Follow the prompts to Install. The app is release-signed, so Android will warn it's from an unknown source - this is expected.
- Open DroidStar 9M2PJU and configure your callsign, DMR ID, and host. Vocoders are built in - no extra downloads needed.
Updating? Just download the new APK and install it over the old one. All builds use the same release key, so your settings are preserved - no need to uninstall first.
Frequently Asked Questions
Everything you need to know about DroidStar 9M2PJU Mod
