OpenHT

Open-source Android controller for VGC / Benshi-protocol radios with Near Repeater, APRS map, Weather Monitoring, and Android Auto support.

📱 Screenshots

Dashboard	Frequency Control	Near Repeater
APRS Map	Spotter Network

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Supported Radios

Radio	Status
Vero VR-N76	✅ Primary test device
Vero VR-N7600	✅ Target hardware
Vero VR-N7500	🔬 Untested (protocol compatible)
BTech UV-Pro	🔬 Untested (protocol compatible)
RadioOddity GA-5WB	🔬 Untested (protocol compatible)

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Why OpenHT?

The vendor HT / BS HT app works, but has significant gaps:

• No "Near Repeater" function — you can't quickly find and tune the closest open repeater
• No offline repeater database — useless without cell service
• No Android Auto integration — dangerous to use while driving
• No open APRS station map with POI markers
• No NOAA weather alerts or NWR auto-monitoring
• Closed source — no ability to fix bugs or extend features

OpenHT fills those gaps.

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Features

✅ Implemented

Radio Control

• Bluetooth connection to radio via RFCOMM (Bluetooth Classic)
• VFO tuning — push any frequency to Band A or Band B with FM + Wide forced
• Channel write — write named channels with CTCSS/DCS tones to any group/slot
• Band B auto-tune — tune Band B to NOAA Weather Radio or SKYWARN frequency on alert

Near Repeater

• GPS-based lookup of closest open repeaters
• 3-tier data fallback: RepeaterBook Content Provider (live) → imported GPX → bundled Colorado GPX
• Sort by distance, filter by band (2m / 70cm), FM-compatible filter
• One-tap tune: pushes frequency directly to radio via Bluetooth
• Batch write up to 32 nearest repeaters to radio Group 6
• Data source indicator (live / GPX / CO) shown in AppBar

APRS

• Live APRS station map with decoded packet markers on OpenStreetMap
• Station list with GPS-relative distance
• Beacon and iGate configuration (in Settings)
• Spotter Network overlay

Weather Monitoring

• NOAA Weather Alerts via NWS API — 5-minute background polling
• Push notifications for Extreme and Severe alerts (POST_NOTIFICATIONS permission)
• Client-side SAME code filtering — only alerts matching your county FIPS
• Alert deduplication — each alert ID notified only once per session
• NWR Station list — distance-sorted nearest Weather Radio transmitters
  • Live fetch from NOAA; silently falls back to bundled CO/KS stations when offline
• NWR auto-monitor — tunes Band B to nearest NWR transmitter

Emergency Auto-Tune

• Polls NWS every 60 seconds for Tornado and Severe Thunderstorm Warnings
• Priority 1: Auto-tunes to served-agency SKYWARN repeater from loaded frequency plan
• Priority 2: Falls back to nearest NWR transmitter matching the alerted county SAME code
• Frequency lock for 5 minutes with dismissable banner

Frequency Plans (Deploy Mode)

• JSON-based frequency plan format — define repeater/simplex/SKYWARN channels for a region
• Write an entire plan to a radio group (e.g., Group 3) with one tap, streaming progress
• FIPS-linked: emergency auto-tune looks up the plan by county FIPS code
• Bundled plan: ppraa_el_paso.json (El Paso County, CO — PPARES, SKYWARN, PPRAA, RACES, PUEBLO WX, NOAA WX)

Settings & Developer Tools

• Restructured settings: Weather Monitoring, APRS, Frequency Plans, Channels & Radio, Developer
• Channel Manager — browse, edit, and export radio channels as CSV
• Radio Debug Terminal — live HEX log of TX/RX bytes, manual tune/scan buttons

🚧 In Progress

• Android Auto UI (CarAppService declared; List template for repeater selection)
• Audio streaming over BT headset (requires libsbc bindings in flutter_benlink)
• Winlink / BBS integration (port from HtStation)
• BLE connection mode (in addition to RFCOMM)

📋 Planned

• Offline repeater DB download by state
• APRS beacon transmission (with callsign + smart beaconing)
• Additional regional frequency plans (submit a PR!)
• APK sideload without Play Store

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Architecture

lib/
├── main.dart                          # App entry, Provider setup, notifications init
├── bluetooth/
│   └── radio_service.dart             # Wraps flutter_benlink; VFO tune, channel write, Band B
├── models/
│   ├── repeater.dart
│   ├── nwr_station.dart               # NOAA Weather Radio transmitter model
│   └── weather_alert.dart             # NWS alert with SAME codes + id
├── services/
│   ├── gps_service.dart               # Continuous GPS tracking
│   ├── noaa_service.dart              # NWR stations + NWS alerts + polling + notifications
│   ├── weather_alert_controller.dart  # Emergency auto-tune (SKYWARN plan → NWR fallback)
│   ├── freq_plan_service.dart         # Load & write regional frequency plans (Stream<int>)
│   ├── repeaterbook_connect_service.dart  # RepeaterBook Content Provider bridge
│   └── repeater_cache.dart            # SQLite repeater cache
├── aprs/
│   ├── aprs_packet.dart               # APRS packet parser
│   └── aprs_service.dart              # Packet stream manager
└── screens/
    ├── dashboard/                     # Main radio status screen
    ├── near_repeater/                 # Near Repeater (3-tier data, batch write)
    ├── aprs_map/                      # APRS stations on OpenStreetMap
    ├── weather/                       # NWR stations + active alerts list
    └── settings/                      # Weather, APRS, Freq Plans, Channels, Developer

Assets

assets/
├── repeaters/                         # Bundled CO repeater GPX (offline fallback)
├── transmitters/
│   └── test_transmitters.json         # Bundled NWR transmitters (CO + KS)
└── freq_plans/
    └── ppraa_el_paso.json             # El Paso County, CO frequency plan

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Getting Started

Prerequisites

• Flutter SDK ≥ 3.10
• Android Studio / Android SDK (API 26+)
• Android device with Bluetooth (BT Classic / RFCOMM support)
• VGC radio paired to your Android device via system Bluetooth settings

Build

git clone https://github.com/repins267/OpenHT.git
cd OpenHT
flutter pub get
flutter run

Pairing your radio

1. Power on your VGC radio
2. Android Settings → Bluetooth → Pair new device
3. Radio will appear as VR-N76, VR-N7600, or similar
4. Pair it — you may need to do this twice (audio + data channels)
5. Open OpenHT → Settings → Scan for Radio → Connect

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Near Repeater Flow

GPS fix
  → Query RepeaterBook Content Provider (live, if RB app installed)
  → OR: load user-imported GPX file
  → OR: load bundled Colorado GPX (always available offline)
  → Display sorted list (distance, tone, FM filter, band)
  → Tap repeater → push VFO frequency to radio via Bluetooth
  → OR: "Write to Radio" → batch program Group 6 with top 32 results

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Weather Alert Flow

WeatherAlertController (60s poll)
  → NWS API: active alerts for GPS position
  → Match: Tornado Warning or Severe Thunderstorm Warning
  → Check SAME code against loaded frequency plans
      → Found SKYWARN channel? → Auto-tune Band A (Priority 1)
      → No plan? → NWR transmitter by SAME code → Auto-tune Band A (Priority 2)
  → Lock frequency 5 min, show dismissable banner

NoaaService (5 min poll — Weather tab)
  → NWS API: all active alerts for position
  → Filter by SAME code (user's county FIPS)
  → Push notification for Extreme / Severe alerts (deduped by alert ID)

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Frequency Plan Format

Plans live in assets/freq_plans/<id>.json:

{
  "id": "ppraa_el_paso",
  "name": "PPRAA / El Paso County ARES",
  "fips": "008041",
  "channels": [
    { "slot": 0, "name": "PPARES",  "rx_mhz": 147.345, "tx_mhz": 146.745, "tone_hz": 107.2 },
    { "slot": 1, "name": "SKYWARN", "rx_mhz": 146.970, "tx_mhz": 146.370, "tone_hz": 100.0 }
  ]
}

fips must match the 6-digit county code used in NWS SAME codes. The channel named SKYWARN is used for emergency auto-tune.

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Android Auto

OpenHT declares a CarAppService targeting the Navigation category. Android Auto UI will use:

• List template — browse Near Repeater results while driving
• Navigation template — APRS map with POI markers

⚠️ Android Auto requires testing with the Desktop Head Unit (DHU) emulator before deployment.

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Credits & Attribution

This project stands on the shoulders of:

Project	Author	Role
benlink	Kyle Husmann KC3SLD	Reverse-engineered the Benshi BT protocol
flutter_benlink	SarahRoseLives	Dart/Flutter port of benlink
aprs-parser	Lee K0QED	APRS packet parsing
HtStation	Ylianst	Node.js base station — architecture inspiration
HTCommander	Ylianst	Windows desktop client — feature reference
RepeaterBook	RepeaterBook.com	Repeater database API
NOAA / NWS	NOAA	Weather alerts API and NWR transmitter data

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License

Apache-2.0 — see LICENSE

An amateur radio license is required to transmit using this software.
Get licensed: arrl.org/getting-licensed

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Contributing

PRs welcome. Areas of highest value right now:

1. Regional frequency plans — add a JSON plan for your county/ARES group
2. Android Auto CarAppService full implementation
3. APRS beacon TX — smart beaconing with callsign config
4. Audio streaming — BT headset TX/RX (needs flutter_benlink libsbc bindings)
5. Testing with UV-Pro, GA-5WB, VR-N7500 hardware

Please open an issue before starting large features.

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🔐 Why was this built?

Read the Privacy & Security Audit for details on vendor hardware tracking and our mitigation strategies.