IoT Weight Tracking System with Mobile App

IoT system integrating ESP32 hardware, Firebase Realtime Database, and a Kotlin Android application for weight tracking with automatic cloud synchronization.

The Challenge

Building a complete end-to-end IoT product: from the physical weight sensor to a mobile app with user profiles, history, and trend analysis. The challenge included reliable wireless communication between hardware and cloud, and instant data synchronization.

My Role

As IoT and mobile developer, I implemented all product layers:

• Programmed the ESP32 firmware in C++ with weight sensors and WiFi connectivity
• Configured Firebase Realtime Database for instant data synchronization
• Developed the Android app in Kotlin with authentication and multiple profiles
• Implemented the automatic hardware calibration system
• Designed the history visualization and trend analysis features

Technical Approach

Hardware:

• ESP32 as microcontroller with high-precision weight sensors
• Bidirectional WiFi connectivity
• Automatic calibration and power consumption optimization

Cloud:

• Firebase Realtime Database for instant synchronization between scale and app
• Firebase Authentication for multi-user profile management

Mobile app:

• Kotlin for native Android development
• Weight evolution history and charts
• Customizable notifications and reminders
• Trend analysis and goal progress tracking

Outcome

Functional and scalable IoT product demonstrating the complete integration of embedded hardware with cloud services and native mobile development.