Drink Safety System - HackViolet 2026

A cross-platform IoT solution to protect drinks from tampering. When the system detects unauthorized access to a protected drink, it immediately alerts the user and their emergency contacts via push notifications and SMS.

SipSafe consists of three components that work together:

1. ESP32 Device - Hardware that detects when a drink container lid is removed
2. Mobile Apps - iOS and Android apps for device control and alerts
3. Supabase Backend - Database, authentication, and notification delivery

See Alternatives to see the thought process/design choices/things we tried.

┌─────────────────┐     BLE      ┌─────────────────┐
│   ESP32 Device  │◄────────────►│   Mobile App    │
│  (Capacitive    │              │  (iOS/Android)  │
│   Touch + BLE)  │              └────────┬────────┘
└─────────────────┘                       │
                                          │ HTTPS
                                          ▼
                              ┌───────────────────────┐
                              │    Supabase Backend   │
                              ├───────────────────────┤
                              │ • PostgreSQL Database │
                              │ • Auth (Email/Apple)  │
                              │ • Edge Functions      │
                              │   - Push Notifications│
                              │   - SMS via Vonage    │
                              └───────────────────────┘

1. Setup: User pairs ESP32 device with mobile app via Bluetooth
2. Protection: User places drink under device and taps "Arm" in app
3. Detection: ESP32 monitors capacitive touch sensor for lid removal
4. Alert: If lid removed while armed:
   • ESP32 sounds buzzer alarm
   • BLE notification sent to app
   • App logs incident to Supabase
   • Edge function sends iOS push notification
   • Edge function sends SMS to emergency contacts
5. Review: User can view alert history and drink tracking in app

SipSafe/
├── SipSafe/                    # iOS App (SwiftUI)
│   ├── SipSafeApp.swift        # App entry point
│   ├── MainTabView.swift       # Tab navigation
│   ├── SupabaseClient.swift    # Supabase singleton
│   ├── Env.swift               # Environment config
│   ├── AppDelegate.swift       # Push notification handling
│   ├── auth/                   # Authentication views
│   ├── bluetooth/              # BLE manager
│   ├── device/                 # Device pairing UI
│   ├── home/                   # Emergency contacts
│   ├── friends/                # Friend management
│   ├── drinks/                 # Drink tracking
│   ├── notifications/          # Alert history
│   ├── account/                # User settings
│   └── location/               # GPS for alerts
│
├── app/                        # Android App (Kotlin/Compose)
│   └── src/main/java/com/sipsafe/app/
│       ├── MainActivity.kt     # App entry point
│       ├── MainTabView.kt      # Tab navigation
│       ├── SipSafeApp.kt       # Application class
│       ├── SupabaseClient.kt   # Supabase singleton
│       ├── auth/               # Authentication
│       ├── bluetooth/          # BLE manager
│       ├── device/             # Device pairing UI
│       ├── home/               # Home screen
│       └── account/            # User settings
│
└── Esp32Files/                 # ESP32 Firmware
    └── drinkguard/
        └── drinkguard.ino      # Main firmware

• Xcode 15+ (iOS)
• Android Studio Hedgehog+ (Android)
• Arduino IDE with ESP32 board support
• Supabase project with Edge Functions enabled

1. Open SipSafe/SipSafe.xcodeproj in Xcode

2. Configure Supabase credentials in scheme environment variables:

   • Product > Scheme > Edit Scheme > Run > Arguments > Environment Variables
   • Add SUPABASE_URL = your Supabase project URL
   • Add SUPABASE_KEY = your Supabase anon key

3. Configure push notifications:

   • Enable Push Notifications capability
   • Create APNs key in Apple Developer portal
   • Upload key to Supabase project settings

4. Build and run on device (BLE requires physical device)

1. Copy local.properties.example to local.properties

2. Add Supabase credentials:

   SUPABASE_URL=https://your-project.supabase.co
   SUPABASE_KEY=your-anon-key

3. Open project in Android Studio

4. Build and run:

   ./gradlew installDebug

1. Install Arduino IDE with ESP32 board support

2. Open Esp32Files/drinkguard/drinkguard.ino

3. Wire hardware:

   • GPIO 4: Capacitive touch sensor (aluminum foil)
   • GPIO 5: Buzzer
   • GPIO 15: Physical button (INPUT_PULLUP)

4. Upload to ESP32 DevKit board

5. Device will advertise as "SipSafe" via BLE

Detailed Documentation:

• Hardware Guide - Wiring diagram, components, calibration
• Product Assembly - Physical build (scrunchie + foil cover)
• Wiring Diagram (SVG) - Visual wiring reference
• Product Design (SVG) - Product visualization

The ESP32 exposes a BLE GATT service with three characteristics:

Status byte format:

• Bit 0: Armed (1=armed)
• Bit 1: Lid on (1=lid present)

Alert condition: Armed=1 AND Lid=0 (lid removed while armed)

-- User profiles (linked to Supabase Auth)
users
├── userId (uuid, PK)     -- Same as auth.users.id
├── auth_userId (uuid)    -- Foreign key to auth.users
├── email (text)
├── first_name (text)
├── last_name (text)
├── device_token (text)   -- APNs/FCM token for push
└── platform (text)       -- 'ios' or 'android'

-- Emergency contacts for SMS alerts
emergency_contacts
├── id (serial, PK)
├── user (uuid, FK)       -- Owner's userId
└── contact_number (text) -- Phone number

-- Incident log (all state changes)
incident_table
├── incident_id (uuid, PK)
├── userId (uuid, FK)
├── armed (boolean)
├── covered (boolean)
├── battery (text)        -- Device battery level
├── latitude (text)       -- GPS if available
├── longitude (text)
└── created_at (timestamptz)

-- Friend relationships for alert sharing
friends_table
├── friend_id (uuid, PK)
├── friender_id (uuid, FK) -- User who added friend
├── friendee_id (uuid, FK) -- User being added
└── created_at (timestamptz)

-- Notification log
notification_table
├── notification_id (uuid, PK)
├── incident_id (uuid, FK)
├── victim_id (uuid, FK)
├── sent_id (uuid, FK)
└── created_at (timestamptz)

Triggered by database webhook on incident_table INSERT when armed=true AND covered=false.

Actions:

1. Fetches user details and device token
2. Sends APNs push notification to user
3. Invokes Twillio-Test for SMS to emergency contacts
4. Logs notification to notification_table
5. Notifies user's friends

Sends SMS alerts via Vonage API.

Request body:

{
  "number": "XXXXXXXXXXX",
  "userName": "John Doe"
}

Triggered on auth.users INSERT. Creates corresponding record in public users table.

SUPABASE_URL
SUPABASE_SERVICE_ROLE_KEY
APNS_KEY_B64          # Base64 .p8 key
APNS_KEY_ID           # Apple key ID
APNS_TEAM_ID          # Apple team ID
APNS_TOPIC            # Bundle ID
VONAGE_API_KEY
VONAGE_API_SECRET
VONAGE_FROM_NUMBER

Inside of the repo you will need to update the corresponding keys to match your own supabase instance.

• BLE device pairing and control (iOS/Android)
• Email/password authentication
• Apple Sign In (iOS)
• Emergency contacts management (iOS)
• Push notifications (iOS)
• SMS alerts via Vonage
• Friend alert sharing
• Drink tracking
• Alert history
• Offline event queue (ESP32)
• Auto-reconnection

• Android push notifications
• Location sharing in alerts
• Multiple device support
• Drink type categorization

• ultrasonic addition to determne fluid level
• BAC estimator with drink level/quantity of drinks
• multiple levels of capacitive touch
• can/drink guesser based off diameter (can/glass/etc.)

• iOS: SwiftUI with MVVM pattern
• Android: Jetpack Compose with MVI pattern
• ESP32: Arduino with state machine

1. Singleton BLE managers - Ensures single connection across app
2. StateFlow/Published - Reactive UI updates
3. Offline queue - ESP32 stores alerts when disconnected
4. Edge functions - Server-side notification logic

Go to: (Devpost)[https://devpost.com/software/sipsafe?ref_content=user-portfolio&ref_feature=in_progress]

Or see Devpost.md

GPL-2 License. See the License tab.