Gas sensors have revolutionized security applications in the home and industrial sectors, especially in the detection of flammable substances and smoke. One of the most widely used sensors in electronics projects is the sensor MQ-2, a device that stands out for its usability and compatibility with microcontrollers like Arduino. Its capacity to detect gases such as LPG, methane, propane, alcohol and carbon monoxide makes it a indispensable tool in the creation of environmental monitoring systems.
In this article, we will explore in depth the characteristics, operation y applications of the MQ-2 sensor. You will learn how to connect and program the sensor with Arduino, adjusting its sensitivity for precise measurements. In addition, we will address the importance of heating time and how to correctly interpret the values obtained in different environments.
What is MQ-2 sensor?
El sensor MQ-2 It is a device that allows detecting the presence of flammable gases and smoke in the air. Based on a electrochemical mechanism, this sensor varies its resistance when it comes into contact with certain gases, generating an electrical signal that can be interpreted by a microcontroller such as Arduino.
It is a sensor of low cost and easy implementation, making it ideal for gas detection projects in domestic environments, labor and industrial. Its detection range ranges from 200 ppm and 10.000 ppm, allowing the identification of Hazardous substances with an acceptable margin of error.
Operating principle of the MQ-2 sensor
The MQ-2 employs a internal heating element that increases the temperature of the semiconductor material (usually tin dioxide). This material is sensitive to flammable gases and modifies its electrical resistance when exposed to them. variation in conductivity can be measured and converted into a useful signal for detection.
Depending on the gas concentration present in the environment, the sensor generates a proportional voltage which can be processed and analyzed. In its digital mode, a detection threshold through a potentiometer, activating a high or low signal output when said value is exceeded limit.
Components of the MQ-2 sensor module
- MQ-2 gas sensor: main element responsible for detecting gases.
- Circuit board: includes a voltage comparator to manage digital output.
- Trimming potentiometer: allows you to calibrate the sensitivity for gas detection.
- Status LED: Indicates whether the sensor is on and/or has detected any gas.
Connecting the MQ-2 sensor to Arduino
To integrate the MQ-2 with Arduino, it is necessary to connect the power pins and signal correctly. The following details the basic wiring:
- VCC: Connect to the 5V pin of Arduino.
- GND: Connect to the Arduino ground (GND) pin.
- AOUT (analog output): Connect to an Arduino analog input (e.g. A0).
- DOUT (digital output): Connect to an Arduino digital input (e.g. D2).
Warm-up and calibration time
One of the most important aspects when using the MQ-2 is its heating time. The sensor needs a stabilization period for accurate measurements. It is recommended to wait between 10 and 24 hours before performing reliable measurements.
The setting of sensitivity It is done through the potentiometer of the module. By turning it in one direction or the other, you can set up the detection threshold for the digital output, allowing the sensor to act as a switch at certain gas concentrations.
Reading data with Arduino
Arduino can read the analog output of the MQ-2 and display the values in the serial monitor. Below is a sample code which reads the gas concentration:
void setup() { Serial.begin(9600); } void loop() { int sensorValue = analogRead(A0); float voltage = sensorValue * (5.0 / 1023.0); Serial.print("Value: "); Serial.println(voltage); delay(1000); }
This XNUMXth-century code converts the analog reading in a voltage that can be interpreted as the presence of gas in the environment.
Uses and applications of the MQ-2 sensor
The MQ-2 sensor has various applications due to its ability to detect flammable gases and smoke. Some of the most common uses include:
- Domestic gas detectors: to prevent LPG or methane leaks in kitchens and boilers.
- Smoke alarms: integration with security systems for early fire detection.
- Air quality control: indoor gas monitoring to ensure a safe environment.
- Home automation projects: automation of fans or alert systems in the presence of dangerous gases.
Precautions when using the MQ-2 sensor
To ensure safe and efficient use of the MQ-2 sensor, some precautions should be taken into account: Precautions:
- Avoid direct contact with liquids: the sensor is sensitive to moisture and may affect your measurements.
- Do not expose to high temperatures: although it has a system of internal warming, extreme temperatures can damage it.
- Strategic location: to optimal readings, install it in a place where air flows freely.
The MQ-2 sensor is an essential tool in the development of security and environmental monitoring systems. Thanks to its usability y low cost, is widely used in domestic and industrial applications. With proper calibration and adequate warm-up time, it can provide fairly accurate measurements on the presence of flammable gases and smoke in the air. If you're looking to improve home security or develop gas detection projects, the MQ-2 is an excellent choice.