• Author: Felicia Saghin
• Email: felicia.saghin@stud.acs.pub.ro
• Master: SRIC

In today’s connected world, real-time security monitoring at home or in small offices has become both practical and affordable. This project delivers a lightweight IoT door-security solution by combining an ESP32-CAM module with a Hall-effect sensor. Whenever the door opens, the sensor immediately signals the ESP32-CAM to capture a high-resolution image. That image is then uploaded to Firebase Storage, and its publicly accessible URL is written to Firebase Realtime Database. Simultaneously, Twilio’s API is invoked to send an SMS to your smartphone. Finally, a web gallery hosted on Firebase displays the latest snapshot instantly, giving you secure and remote visibility of every entry event.

In many homes and small offices, it’s difficult to know in real time if someone has opened a door while you’re away. Traditional mechanical locks and alarms often only log events locally or rely on manual checks.

This project bridges that gap by providing:

- instant detection of a door opening via a Hall-effect sensor

- automated image capture with an ESP32-CAM module

- cloud storage of each snapshot in Firebase Storage

- real-time notifications via Twilio (SMS)

- live web monitoring through a Firebase-hosted gallery

Hardware Circuit

Connecting Components

Hall-effect Sensor (A3144) Mounted on the door frame. Detects the magnet fixed to the door as it swings past: output goes LOW when the magnet is within 5–10 mm (door closed), and HIGH when it moves away (door open). * VCC → ESP32-CAM 3V3 * GND → ESP32-CAM GND * OUT → ESP32-CAM GPIO13 (`INPUT_PULLUP`)

ESP32-CAM Module Handles image capture, Firebase upload, and Twilio notifications. * Power → VIN pin → +5 V from your battery pack (e.g. USB power-bank or Li-Po + boost converter) * Ground → GND → battery pack GND *(If you’re using the ESP32-CAM-MB shield instead of wiring VIN/GND, just plug your battery’s USB cable into its micro-USB port.)*

USB-Serial Adapter *(only if not using the on-board USB shield)* Required to flash code to the ESP32-CAM. * Adapter TX → ESP32-CAM U0R0 (GPIO3) * Adapter RX → ESP32-CAM U0T0 (GPIO1) * Adapter +5 V → ESP32-CAM VIN * Adapter GND → ESP32-CAM GND

Permanent Magnet Mounted on the door so its north pole passes within 5–10 mm of the Hall sensor when the door is closed. No wiring required.