Mobile Application Development Based on IoT Technology for Smart Door Lock System

Abstract

This report presents the development of a miniature IoT-based smart door lock system integrated with a custom Android application named Jenaela. The system addresses the security limitations of conventional pin tumbler locks, which are vulnerable to lock-picking and offer limited access control. The hardware system consists of an ESP32 DOIT V1 microcontroller, PN532 NFC module, relay with optocoupler integration, a DC-to-DC step-up converter, and a 12V solenoid lock. The software component includes Jenaela, built using TypeScript and the React Native framework, deployed with the Expo toolkit and EAS Build Preview. Unlike prior works that utilized third-party platforms such as Blynk, Jenaela offers full customization and enhanced control. Key features include user authentication, RFID tag registration and deletion, LAN-based device discovery, and unlocking via both RFID and remote switch. Functional testing using the Black Box method confirmed that all features operate correctly. The RFID unlocking method exhibited faster response times than WAN-based unlocking due to fewer dependencies. The results demonstrate the feasibility and effectiveness of integrating IoT hardware with a custom mobile application to improve security through dual access and real- time database interaction.