🤖 Voice-Assistant Health & Fitness Companion

📱 A) Technical Architecture

Technology Stack

Background Processing Strategy

To ensure alarms work even when the app is closed:

• Android Use flutter_background_service + WorkManager to keep a Dart isolate running.
• iOS Use UNUserNotificationCenter for reliability.

Modules Architecture

• Sensor Module: Pedometer (Step Counter) & GPS (Location Manager).
• Voice Engine Module: TTS initialization, Language selection, Audio Session.
• Alert Manager: Schedules tasks, Snooze logic, SOS Loop.
• Emergency Module: SMS sending & phone call triggering.

💾 B) Database Schema

Using Hive boxes or SQLite tables for offline data.

1. UserProfile (Settings)

{
  "id": "user_001",
  "name": "User",
  "selected_voice_gender": "male", // or "female"
  "selected_language": "ur-PK",    // or "hi-IN", "en-US"
  "sos_contact_number": "+92xxx"
}

2. Reminders (Alarms & Meds)

Table: reminders
- reminder_id: UUID
- title: String (e.g., "Medicine Time")
- custom_text: String (e.g., "Ground janey ka waqt ho gaya")
- scheduled_time: TimeStamp
- repeat_interval: ENUM (DAILY, WEEKDAYS)
- category: ENUM (MEDICINE, TASK, HYDRATION)
- is_active: Boolean
- snooze_duration_minutes: Integer

3. ActivityLogs (Fitness)

Table: activity_logs
- log_id: UUID
- type: ENUM (STEP, RUN)
- start_time: Timestamp
- count_steps: Integer
- distance_km: Float
- route_points: JSON (lat/long array)

🔊 C) Custom TTS System Implementation

Logic Flow

1. Trigger: Alarm fires at set time.
2. Fetch: Get `custom_text` and `selected_voice_gender` from DB.
3. Language Mapping:
   • Urdu Script detected → Set `ur-PK`
   • Hindi Script detected → Set `hi-IN`
   • Default → `en-US`
4. Gender Setup:
   • Male → Pitch 0.9, Speed Normal
   • Female → Pitch 1.2, Speed Slow
5. SOS Loop: Repeat TTS 5 times with 3-second delays.

Code Snippet (Dart)

Future speakAlarm(Reminder reminder, UserProfile user) async {
  final tts = FlutterTts();
  
  // 1. Set Language
  await tts.setLanguage(user.languageCode); // e.g., "ur-PK"
  
  // 2. Set Gender Pitch
  if (user.voiceGender == 'female') {
    await tts.setPitch(1.2); 
  } else {
    await tts.setPitch(0.9); 
  }
  
  // 3. Volume Max
  await tts.setVolume(1.0);
  
  // 4. Speak or SOS Loop
  if (reminder.category == 'SOS') {
     for(int i=0; i<5; i++) {
        await tts.speak("HELP! " + reminder.custom_text);
        await Future.delayed(Duration(seconds: 3));
     }
  } else {
     await tts.speak(reminder.custom_text);
  }
}

🎨 D) UI/UX Screen Flow Structure

Design Philosophy: Minimalist, Senior-Friendly, High-Contrast.

1. Dashboard (Main Tab)

• Top: Large Circular Step Counter (e.g., "4,500 / 10,000")
• Middle: Next Upcoming Alarm Card
• Bottom FAB: "+" (Quick Add)

2. Reminders Tab

• List of Cards: "06:00 PM - Medicine"
• Add Interface: Large Time Picker + Text Field

3. Fitness Tab

• Map View with Route
• Stats Cards: Distance, Pace, Time

4. Settings Tab

• Voice Toggle: Large "Male" / "Female" buttons
• SOS: Red Emergency Button + Contact Input

🚀 E) Implementation Roadmap