Autor: Burciu Iustin Florian Email: iustin.burciu@stud.fiir.upb.ro Grupa: AAC

This project focuses on building an embedded system to monitor environmental comfort using the ESP32 development board, along with an LM35 temperature sensor and an MQ-4 gas sensor. It continuously evaluates environmental conditions and computes a comfort score based on temperature and gas readings.

The implementation was initially created as a local web server hosted directly on the ESP32, allowing real-time monitoring from any browser within the same Wi-Fi network. Later, a second version was developed using Firebase Realtime Database, enabling remote data access and logging in real time from anywhere in the world.

The project includes:

• Real-time data acquisition from temperature and gas sensors
• Live display of sensor values and computed comfort score
• Visual charts and indicator LEDs (both virtual and physical)
• Automatic alerts and a persistent log for critical events
• Optional Firebase integration for remote access

Used Components:

• ESP32 DevKit V1 – WiFi + Bluetooth enabled development board
• LM35 – analog temperature sensor
• MQ-4 – analog gas sensor
• 2x LEDs (red and blue) – for visual alerts
• Jumper wires, breadboard

ESP32 Connections:

The system reads data from the LM35 and MQ-4 every 2 seconds and:

• Computes a comfort score between 0 and 100.
• Displays the values and graphs on a local HTML dashboard.
• Logs alerts (dangerous gas levels or max score) in a scrollable event list.
• Activates LEDs and virtual indicators based on thresholds.

In a separate sketch, the system can also:

• Push live data to Firebase Realtime Database
• Use credentials and Web API key
• Display values remotely via a mobile app or web

1. Read Temperature and Gas:

```c float citesteTemperatura() {

int adc = analogRead(pinLM35);
float voltaj = adc * (5.0 / 4095.0);
return voltaj * 100.0;

}

int citesteGaz() {

return analogRead(pinMQ4);

}