Description
MQ8 - Hydrogen Gas Sensor Module
The Hydrogen Gas Sensor Module most used with Arduino is the MQ8 sensor. It is designed to detect hydrogen (H₂) gas in the air and is often used in gas leak detection, hydrogen-powered systems, and safety monitoring setups. The MQ-8 gas sensor is highly sensitive to hydrogen and less sensitive to alcohol and cooking fumes. It could be used in gas leakage detection appliance in domestic and industry.
Technical Specifications:
-
Operating Voltage: 5V DC
-
Detection Range: 100 – 10,000 ppm H₂
-
Gas Detected: Hydrogen (H₂)
-
Analog Output (A0): Varies with gas concentration
-
Digital Output (D0): HIGH/LOW based on threshold (set via potentiometer)
-
Heater Power: ~800–900 mW
- Warm-up Time: ~1–5 minutes for accurate readings
Pinouts:
Connection with Arduino:
Module |
Arduino UNO |
VCC |
5V |
GND |
GND |
A0 |
A0 |
D0 |
D2(Optional) |
Sample code:
Analog reading:
int mq8Pin = A0; // MQ8 A0 pin connected to Arduino A0
void setup() {
Serial.begin(9600); // Initialize Serial Monitor
}
void loop() {
int gasValue = analogRead(mq8Pin); // Read analog value
Serial.print("Hydrogen Gas Level: ");
Serial.println(gasValue); // Print value to Serial Monitor
delay(1000); // 1 second delay
}
Add Buzzer for Gas Leak Alert
int mq8Pin = A0;
int buzzerPin = 8;
int threshold = 400; // Adjust this value after testing
void setup() {
Serial.begin(9600);
pinMode(buzzerPin, OUTPUT);
}
void loop() {
int h2Level = analogRead(mq8Pin);
Serial.print("H₂ Level: ");
Serial.println(h2Level);
if (h2Level > threshold) {
digitalWrite(buzzerPin, HIGH); // Turn buzzer ON
} else {
digitalWrite(buzzerPin, LOW); // Turn buzzer OFF
}
delay(500);
}