Spray Navigator

A React Native Android application built for Three Rivers Mosquito Vector Control to assist field technicians during spray operations. Technicians pair the app with a Bluetooth GPS/fogger module mounted on the spray truck, and the app tracks their route in real time — recording where the sprayer was active — then uploads the data to Google Drive so the main office can review coverage.

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Features

• Live Bluetooth tracking — pairs with an HC-05 Bluetooth module on the spray truck to receive GPS coordinates, speed, elevation, and fogger on/off status in real time
• Map display — plots the spray route as a colored polyline: red where the fogger was active, green where it was off
• Recording — saves each session as a CSV file with timestamp, latitude, longitude, speed, elevation, and fogger state
• Playback — replay any saved recording on the map with play/pause controls and a scrubber slider
• Offline maps — download OpenStreetMap tiles for a defined area so the app works without cellular coverage in the field
• Google Drive sync — sign in with Google to import or export CSV recordings between the device and Drive, giving the main office access to spray records
• File management — view and delete saved recordings directly on the device

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Screenshots

Screenshots coming soon.

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Hardware

The app communicates with an HC-05 Bluetooth Classic module connected to a GPS unit and fogger sensor on the spray truck. The module transmits comma-separated data packets in the format:

<index>,<latitude>,<longitude>,<speed>,<elevation>,<fogger>

The app parses this stream, timestamps each packet with the device clock, and displays/records the data.

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Tech Stack

Area	Library
Framework	React Native 0.75
Navigation	React Navigation 6 (Native Stack)
Maps	react-native-maps
Bluetooth	react-native-bluetooth-classic
Database	react-native-sqlite-storage
Google Auth	@react-native-google-signin/google-signin
Google Drive	@robinbobin/react-native-google-drive-api-wrapper
Offline tiles	react-native-fs + react-native-blob-util
Network status	@react-native-community/netinfo

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Project Structure

src/
├── App.js                  # Root navigator, initializes Google Sign-In and local DB
├── components/
│   ├── Header.js           # Scrollable nav bar present on every screen
│   ├── MapDisplay.js       # Map with polyline rendering (online + offline tiles)
│   ├── ModeSelector.js
│   └── StatusIndicator.js
├── pages/
│   ├── HomePage.js         # Landing screen
│   ├── RecordingPage.js    # Live Bluetooth recording + map
│   ├── PlaybackPage.js     # CSV playback with play/pause slider
│   ├── DeletePage.js       # Manage saved recordings
│   ├── SetRegionPage.js    # Download offline map tiles for a region
│   └── ImportExportPage.js # Google Drive import/export
└── utils/
    ├── BluetoothService.js # HC-05 connection and data stream parsing
    ├── database.js         # SQLite helpers for in-session recording
    ├── export.js           # CSV export and native share sheet
    ├── fileUtils.js        # Local file I/O and Google Drive file operations
    ├── googleSignIn.js     # Google Sign-In configuration and helpers
    ├── screenUtils.js      # Responsive font/padding utilities
    ├── tileDownloader.js   # Downloads and caches OSM tiles
    └── tileStorage.js      # Retrieves cached tiles from local storage

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Setup

Prerequisites

• Node >= 18
• React Native CLI environment (setup guide)
• Android Studio with an Android SDK
• A physical Android device or emulator (Bluetooth features require a real device)

Install dependencies

yarn install

Configure credentials

This repo uses placeholder values for all API keys. Before building, replace the following:

File	Placeholder	What to use
android/app/src/main/AndroidManifest.xml	YOUR_GOOGLE_MAPS_API_KEY	Google Maps Android API key from Google Cloud Console
android/app/google-services.json	All YOUR_* values	Download your own google-services.json from Firebase Console
android/oauth-client-config.json	YOUR_ANDROID_CLIENT_ID, YOUR_PROJECT_ID	OAuth 2.0 client credentials from Google Cloud Console
src/utils/googleSignIn.js	YOUR_WEB_CLIENT_ID	Web client ID from Google Cloud Console

Run on Android

# Start Metro
yarn start

# In a second terminal
yarn android

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Android Permissions

Permission	Purpose
ACCESS_FINE_LOCATION / ACCESS_COARSE_LOCATION	GPS positioning
BLUETOOTH_CONNECT / BLUETOOTH / BLUETOOTH_ADMIN	HC-05 Bluetooth pairing and communication (Android 12+ requires BLUETOOTH_CONNECT)
INTERNET	Map tiles and Google Drive API
WRITE_EXTERNAL_STORAGE / READ_EXTERNAL_STORAGE	Saving and reading CSV recording files

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License

This project was developed for Three Rivers Mosquito Vector Control. All rights reserved.