Guide for MQ-2 Gas/Smoke Sensor with Arduino
Содержание
- The MQ-2 Gas Sensor
- How does it work?
- Pin Wiring
- Example: Gas Sensor with Arduino
- Schematics
- Video demonstration
This guide shows how to build a smoke detector that beeps when it detects flammable gas or smoke.
The MQ-2 Gas Sensor
The MQ-2 smoke sensor is the one in the following figure:
The MQ-2 smoke sensor is sensitive to smoke and to the following flammable gases:
- LPG
- Butane
- Propane
- Methane
- Alcohol
- Hydrogen
The resistance of the sensor is different depending on the type of the gas.
The smoke sensor has a built-in potentiometer that allows you to adjust the sensor digital output (D0) threshold. This threshold sets the value above which the digital pin will output a HIGH signal.
How does it work?
The voltage that the sensor outputs changes accordingly to the smoke/gas level that exists in the atmosphere. The sensor outputs a voltage that is proportional to the concentration of smoke/gas.
In other words, the relationship between voltage and gas concentration is the following:
- The greater the gas concentration, the greater the output voltage
- The lower the gas concentration, the lower the output voltage
The output can be an analog signal (A0) that can be read with an analog input of the Arduino or a digital output (D0) that can be read with a digital input of the Arduino.
Pin Wiring
The MQ-2 sensor has 4 pins.
Pin | Wiring to Arduino Uno |
A0 | Analog pins |
D0 | Digital pins |
GND | GND |
VCC | 5V |
Example: Gas Sensor with Arduino
In this example, you will read the sensor analog output voltage and when the smoke reaches a certain level, it will make sound a buzzer and a red LED will turn on.
When the output voltage is below that level, a green LED will be on.
Parts needed:
So, for this example, you’ll need:
You can use the preceding links or go directly to MakerAdvisor.com/tools to find all the parts for your projects at the best price!
Schematics
Follow these schematics to complete the project:
Upload the following sketch to your Arduino board (feel free to adjust the variable sensorThres with a different threshold value):
Video demonstration
Watch this quick video demonstration to see this project in action:
I hope you found this guide useful.
Share this post with a friend that also likes electronics!
You can contact me by leaving a comment. If you like this post probably you might like my next ones (click here to subscribe my blog).
Источник: