This repository contains the Arduino code and documentation for interfacing an Arduino Uno with an MG811 CO2 sensor. The aim of this project is to measure the CO2 concentration in the air and display it in parts per million (PPM) on the Arduino's Serial Monitor.

• Arduino Uno
• MG811 CO2 Sensor Module
• Breadboard
• Jumper Wires

1. Connect the VCC of the MG811 to the 5V pin on the Arduino Uno.
2. Connect the GND of the MG811 to the GND pin on the Arduino Uno.
3. Connect the AOUT (analog output) of the MG811 to the A0 pin on the Arduino Uno.

• Arduino IDE

The setup function initializes the serial communication and sets up the sensor pin.

const int sensorPin = A0;  // Define the analog input pin for MG811

void setup() {
  Serial.begin(9600);       // Initialize serial communication at 9600 baud rate
}

The loop function reads the sensor value, converts it to voltage, then to PPM (CO2 concentration), and prints it to the Serial Monitor.

void loop() {
  int sensorValue = analogRead(sensorPin);   // Read the sensor output
  float voltage = sensorValue * (5.0 / 1023.0);  // Convert to voltage
  float co2_concentration = voltageToPPM(voltage);  // Convert voltage to CO2 PPM

  Serial.print("CO2 Concentration: ");
  Serial.print(co2_concentration);
  Serial.println(" PPM");

  delay(1000);  // Wait for 1 second before reading the sensor again
}

The voltageToPPM function converts the voltage to CO2 concentration. This formula needs to be calibrated for accuracy.

float voltageToPPM(float voltage) {
  // Placeholder conversion formula. Replace with the calibrated one.
  float ppm = voltage * 400;  // Example conversion
  return ppm;
}

Calibrate the sensor according to the MG811 datasheet for accurate readings.