IoT Based Coal Mine Safety Monitoring and Alerting System

This guide will help you develop an IoT-based Coal Mine Safety Monitoring and Alerting System. The system will monitor critical parameters such as gas levels, temperature, and humidity within the mine and alert personnel in case of unsafe conditions.

Components Required

• Microcontroller or development board (e.g., Arduino, ESP8266, or ESP32)
• Gas sensors (e.g., MQ series for methane, carbon monoxide)
• Temperature and humidity sensor (e.g., DHT22)
• Air quality sensor (e.g., MQ135)
• Buzzer or alarm module
• Relay module (for controlling alarms or ventilation systems)
• Wi-Fi module (if not integrated into the microcontroller)
• Power supply (e.g., 5V DC adapter or battery)
• Cloud service account (e.g., ThingSpeak, Blynk, or AWS IoT)
• Connecting wires and breadboard

Setting Up the Hardware

Follow these steps to set up the hardware:

1. Connect the Sensors

   Connect gas sensors, temperature and humidity sensors, and air quality sensors to the microcontroller. Use appropriate pins for data, power, and ground connections.

2. Connect the Alarm Module

   Connect the buzzer or alarm module to the microcontroller via a relay module. The relay will control the alarm based on the sensor readings.

3. Power the System

   Ensure that the microcontroller and all connected components are powered correctly. Use a stable power supply to avoid fluctuations.

Programming the Microcontroller

Write the code to read sensor data and trigger alarms based on unsafe conditions. Below is a basic outline of the code using Arduino:

                #include <DHT.h>
                #include <WiFi.h>
                #include <PubSubClient.h>

                #define GAS_SENSOR_PIN A0
                #define TEMP_HUMIDITY_PIN 2
                #define BUZZER_PIN 3
                #define MQ135_PIN A1

                DHT dht(TEMP_HUMIDITY_PIN, DHT22);
                WiFiClient espClient;
                PubSubClient client(espClient);

                const char* ssid = "your_SSID";
                const char* password = "your_PASSWORD";
                const char* mqtt_server = "broker_address";
                const char* mqtt_topic = "mine/safety";

                void setup() {
                    Serial.begin(9600);
                    dht.begin();
                    
                    pinMode(BUZZER_PIN, OUTPUT);
                    
                    setup_wifi();
                    client.setServer(mqtt_server, 1883);
                }

                void setup_wifi() {
                    delay(10);
                    Serial.println();
                    Serial.print("Connecting to ");
                    Serial.print(ssid);
                    
                    WiFi.begin(ssid, password);
                    while (WiFi.status() != WL_CONNECTED) {
                        delay(500);
                        Serial.print(".");
                    }
                    Serial.println(" connected");
                }

                void reconnect() {
                    while (!client.connected()) {
                        Serial.print("Attempting MQTT connection...");
                        if (client.connect("MineSafetyClient")) {
                            Serial.println("connected");
                            client.subscribe(mqtt_topic);
                        } else {
                            Serial.print("failed, rc=");
                            Serial.print(client.state());
                            Serial.println(" try again in 5 seconds");
                            delay(5000);
                        }
                    }
                }

                void loop() {
                    if (!client.connected()) {
                        reconnect();
                    }
                    client.loop();
                    
                    float temperature = dht.readTemperature();
                    float humidity = dht.readHumidity();
                    int gasLevel = analogRead(GAS_SENSOR_PIN);
                    int airQuality = analogRead(MQ135_PIN);

                    if (temperature > 35 || gasLevel > 300 || airQuality > 400) {
                        digitalWrite(BUZZER_PIN, HIGH); // Turn on buzzer
                    } else {
                        digitalWrite(BUZZER_PIN, LOW); // Turn off buzzer
                    }

                    String payload = "Temperature: " + String(temperature) + " C, Humidity: " + String(humidity) + " %, Gas Level: " + String(gasLevel) + ", Air Quality: " + String(airQuality);
                    client.publish(mqtt_topic, payload.c_str());
                    
                    delay(10000); // Wait 10 seconds before the next loop
                }
            

This code connects to a Wi-Fi network, reads data from the sensors, and triggers the alarm if any parameter exceeds the safety threshold. The data is also published to an MQTT broker for remote monitoring.

Setting Up Cloud Integration

To visualize and analyze the data, integrate the system with a cloud service. For instance, you can use ThingSpeak, Blynk, or AWS IoT. Configure your cloud service to receive and display the data published by the microcontroller.

Testing and Calibration

Test the system by simulating different unsafe conditions and verifying that the alarm triggers appropriately. Adjust the thresholds in the code as needed to ensure reliable safety monitoring.