Gas detection using MQ8 H2 sensor

Ensure safety with EzloPi automation!

Top Projects

LED ON/OFF

LED ON/OFF with Push Button

DHT22 Temperature-Humidity Sensor

AC Lamp setup with relay and momentary switch

Gas detection using MQ8 H2 sensor

The EzloPi smart devices provide automation through simple, customizable use with our open-source EzloPi platform, making daily life easier and improving human-machine interactions.

Before moving into this example, it is very important to know about the device registration, provisioning and converting the ESP32 device into an EzloPi device along with knowledge of Web Flasher, MiOS Mobile Application for Android/iOS and the MiOS Web Application.

1. About this example

This project aims to interface the MQ8 H2 gas sensor module and a buzzer with the EzloPi device for gas leak detection in industries. The MQ8 hydrogen (H2) detection sensor is an essential component in industrial safety systems, designed to detect hydrogen gas concentrations in the environment. Its timely detection capabilities can prevent accidents and ensure a safe working environment. Buzzer is also incorporated in the project for providing audible feedback to the user. Many other smart devices and sensors can also be integrated in this project for a more dynamic system. Through the MiOS app, users can remotely monitor the H2 gas concentration which is displayed on the MiOS smart application.

3. Circuit Diagram & Interface

The following components are required for interfacing with the EzloPi device:

as an EzloPi smart device.
MQ8 H2 Gas sensor module.
MH-FMD Buzzer

The wiring diagram of ESP32 30 pin is represented as follows:

The following connections are made in order to complete the circuit setup.

From ESP32 to the MQ8 gas sensor:

ESP32	MQ8 sensor
VIN	VCC
GND	GND
D5	DO
D33	A0

From ESP32 to the Buzzer:

ESP32	Buzzer
VIN	VCC
GND	GND
D32	I/O

4. Interfacing the Soil moisture sensor and DHT22 with the EzloPi Web Flasher

1. Set up your device/hardware by visiting config.ezlopi.com

Now, click on the Connect Device button and a pop-up window will appear.

Now, select COM Port to which your ESP32 device is connected. In our case, the COM3 port is used.

Click Connect

If you are new to this and it's your first time configuring, select Create new Device ID. Enter Wifi SSID and Wifi Password.
In the Device Configuration, tab click on Other.

A window will open for inputting the following parameters:

Set a Device name of your choosing. In our case, we set it to the Hydrogen Gas Sensor.
Set Device subtype to MQ8 H2 Sensor.
Check the box of GPIO 1.
Set the GPIO 1 to 25.
Check the box of GPIO 2.
Set the GPIO 2 to 33.
Then Click Apply Button.

In the Device Configuration, tab click on Digital Output.

A window will open for inputting the following parameters:

Set a Device name of your choosing. In our case, we set it to Buzzer.
Set Device subtype to LED.
Set OUT GPIO to 32.
Set Resistor to PULL UP.
Set Default value to LOW.
Then Click Apply Button.
After clicking the apply button you can see a table of your setting in the device configuration tab.
Press the Flash Device button.

A window will appear on the bottom right side of the screen displaying “Please press BOOT button while flashing begins.”

Hold the BOOT button down until the next window appears on the bottom right side of the screen which says “Installation prepared. Please release the boot button now.”

Release the BOOT button from your ESP32 when this pop-up on the bottom right window appears.

After some time, a popup will appear saying Device Flashed Successfully! This means that your device has been set up successfully.

5. MiOS Web Dashboard

After configuring the controller with the EzloPi web flasher, head to ezlogic.mios.com

Use the same credential to log in that you used for configuring the controller with the web flasher.

On the MiOS web dashboard, you will see the tiles of your connected devices as shown above labeled as MQ8 Hydrogen Gas sensor and Buzzer for alarm. Currently, no gas is being detected by the sensor therefore the MQ8 sensor shows zero value and buzzer tile also shows the “Off” message.

MeshBots:

On the left side of the screen under Automation, click on MeshBots.
On meshbot screen, click on Create new MeshBot button present on the top right corner of the screen.
After clicking on Create new MeshBot, you will see this now under Automation MeshBot click on EzloPi.

On the next screen you will see that we can create a name of our choosing, in this case we write it as Test008.

In the trigger tab you can set the TRIGGER for your device and in the ACTION tab you can set the action to be performed based on the trigger which you have created.

Set these things in TRIGGER section:

Set Node Type to Device.
Set the Node to Hydrogen Gas Sensor.
Set the Capability to Gas alarm.
Set the value to combustible_gas_detected.

Set these values in the TRUE part of the ACTION section.

Set Node type to Device.
Set Controllable to Buzzer.
Set Capability to switch.
Set value to true.

Set these values in the FALSE part of the ACTION section.

Set Node type to Device.
Set Controllable to Buzzer.
Set Capability to switch.
Set value to false.
After clicking the apply button you can see a table of your setting in the Current configuration tab.

After clicking the save button you can see this screen on the top right corner of the screen.

Here you can see your saved MeshBot. Now click on Dashboard.

Now as seen above, the tile is showing that when the MQ8 hydrogen gas sensor gets a high value of gas concentration which means that it detects a gas leak, therefore the buzzer also gets turned ON or triggered because of the rules we have set in the meshbot.

6. MiOS App

You can download the MIOS Android app from the Google Play Store and Apple App Store.

After downloading the app, proceed to install the application and open it.

Using the MIOS mobile application, create a new Ezlo Cloud account using the sign-up option. If you already have an account, you may proceed to log in.

After successfully logging in, you will be able to see the number of controllers connected such as a lamp, fan, or any other device in the MiOS app. Tap on any controller of your desired ID:

You will be able to see the status of your controller whether it is online or offline. Access the device dashboard, and tap the device. The following view of the dashboard will appear:

On the MiOS mobile dashboard, you will see the tiles of your connected devices as shown above labeled as MQ8 Hydrogen Gas sensor and Buzzer for alarm. Currently, no gas is being detected by the sensor therefore the MQ8 sensor shows zero value and buzzer tile also shows the “Off” message.

Now as seen above, the tile is showing that when the MQ8 hydrogen gas sensor gets a high value of gas concentration which means that it detects a gas leak, therefore the buzzer also gets turned ON or triggered because of the rules we have set in the meshbot.