The MQ135 Gas Sensor Library for Proteus allows you to simulate air quality monitoring by detecting gases such as Ammonia ( NH3cap N cap H sub 3 ), Nitrogen Oxides ( NOxcap N cap O sub x ), Alcohol, Benzene, smoke, and CO2cap C cap O sub 2
. Since the MQ135 is not a built-in component in standard Proteus installations, you must download and add an external library to use it in your schematic designs. Where to Download
Several community-contributed libraries are available for download:
The Electronics: Offers a dedicated MQ135 library including simulation HEX files The Electronics.
GitHub Repositories: You can find library files (LIB and IDX) from contributors like satyamkr80 or iamnarendrans.
The Engineering Projects (TEP): Provides a general "Gas Sensor Library" that often includes multiple MQ-series sensors The Engineering Projects. Installation Steps
To get the library working in Proteus 7 or 8, follow these steps:
Extract Files: Download and unzip the library folder. You should see files with extensions like .LIB, .IDX, and sometimes .HEX. Locate Proteus Library Folder:
Proteus 8: Navigate to C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY. Note: ProgramData is a hidden folder; you may need to enable "Hidden Items" in Windows View settings.
Proteus 7: Navigate to C:\Program Files (x86)\Labcenter Electronics\Proteus 7 Professional\LIBRARY.
Copy and Paste: Move the .LIB and .IDX files into the Proteus LIBRARY folder.
Restart Proteus: Close and reopen the software to refresh the component database. How to Use the Sensor in Simulation
Once installed, you can find the sensor by searching for "MQ135" in the Pick Devices window.
Connection: The sensor typically features four pins: VCC (5V), GND, Analog Out (A0), and Digital Out (D0).
HEX File Requirement: For some versions, you must double-click the sensor in your schematic and link the provided .HEX file in the "Program File" property box to enable active simulation behavior.
Simulation Control: Many Proteus gas sensors include a "Test Pin" or logic toggle to simulate different gas concentrations, allowing you to see how your Arduino or microcontroller code reacts to changes. MQ135 Gas Sensor Simulation in proteus - The Electronics mq135 gas sensor library for proteus download upd work
To simulate the MQ135 Gas Sensor in Proteus, you must download and manually add external library files to the software’s installation directory. Proteus does not include these sensors by default. Download Sources for MQ135 Library The most reliable current sources providing functional files for Proteus 7 and 8 include: The Engineering Projects (TEP)
: Provides a comprehensive "Gas Sensor Library" package that includes the MQ135 along with other MQ-series sensors. The Electronics
: Offers a specific MQ135 simulation package including a dedicated file for the sensor's internal logic. GitHub (Satyamkr80 Repository) : A direct source for the and associated library files. Step-by-Step Installation Guide Extract the Files : After downloading the file, extract it to find three critical files: Locate Proteus Folders : Navigate to
C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY ProgramData
is a hidden folder; enable "Hidden Items" in Windows View settings). : Navigate to
C:\Program Files (x86)\Labcenter Electronics\Proteus 7 Professional\LIBRARY Copy and Paste files into the If there is a folder in your Proteus directory, paste the
files there, or keep them in a dedicated project folder for easy browsing. Restart Proteus
: Close and reopen Proteus to refresh the component database. Configuring the MQ135 in your Circuit Pick Component
: Search for "MQ135" in the component library and place it on your schematic. Upload HEX File Double-click the MQ135 sensor in your workspace. Edit Properties window, find the "Program File" Click the folder icon and select the file you downloaded earlier. Simulation Logic : The sensor typically has a . During simulation, applying a
logic state to this pin simulates the presence of gas, causing the sensor's Output Pin to send a signal to your microcontroller (e.g., Arduino). Elektor Magazine If you are also using an for this project, you will need the Arduino MQ135 Library to handle CO2 and air quality calculations in your code. Arduino Library List Are you planning to interface this with an Arduino Uno or a different microcontroller for your simulation? MQ135 Gas Sensor Simulation in proteus - The Electronics
To use the MQ135 gas sensor Go to product viewer dialog for this item.
in Proteus, you need to download and manually install external library files, as it is not included in the software by default. 🛠️ Step 1: Download & Prepare Files
You need a specific set of library files often available from sources like The Engineering Projects or GitHub.
After downloading the .zip or .rar archive, extract it to find these three essential files: MQ135.LIB (Library file) MQ135.IDX (Index file)
MQ135.HEX (Simulation hex file—crucial for the sensor to "work" during runtime) 📂 Step 2: Install Library in Proteus The MQ135 Gas Sensor Library for Proteus allows
You must place the downloaded files into your Proteus installation directory. The path varies depending on your version:
For Proteus 8 Professional:C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY(Note: The ProgramData folder is hidden by default. Use the "View" tab in File Explorer to check "Hidden Items".)
For Proteus 7:C:\Program Files (x86)\Labcenter Electronics\Proteus 7 Professional\LIBRARY
Action: Copy the .LIB and .IDX files and paste them into the LIBRARY folder. 🔌 Step 3: Configure the Sensor in your Schematic
Pick the Device: Open Proteus, go to Component Mode (P), and search for "MQ135". Select it and place it on your workspace.
Add the Hex File: This is the step most users miss. Without it, the sensor won't produce a signal. Right-click the MQ135 component and select Edit Properties. Find the Program File field.
Click the folder icon and select the MQ135.HEX file you downloaded earlier. Click OK. 🧪 Step 4: Simulating Gas Levels
Since you can't blow actual smoke into a simulation, the library uses a Test Pin.
Connect a Logic State or Logic Toggle to the Test Pin of the MQ135. Logic 0: Represents clean air (Normal output).
Logic 1: Simulates gas presence (The output pin will go HIGH or change its analog value).
💡 Pro Tip: For a complete project, interface the MQ135 with an Arduino Uno in Proteus. Use the Arduino Library for Proteus to read the sensor's analog output. If you'd like, I can provide: A sample Arduino code to read the MQ135 values.
Instructions for calibrating the sensor for specific gases like CO2 or Ammonia.
A list of compatible LCD libraries to display the air quality data. MQ135 Gas Sensor Simulation in proteus - The Electronics
To simulate the MQ135 Gas Sensor in Proteus, you must manually add specific library files (typically .LIB, .IDX, and .HEX) since this sensor is not included in the default Proteus installation. 📂 Where to Download the Library
Multiple reputable engineering communities provide tested MQ135 libraries for Proteus 7 and 8: Troubleshooting Tips
The Engineering Projects (TEP): Offers a comprehensive Gas Sensor Library that includes the MQ-2 through MQ-9 series. Users must often wait for a timer or create an account to access the .zip or .rar files.
The Electronics: Provides a specific MQ135 Gas Sensor Simulation library with a direct download link to a GitHub repository.
Karan-nevage (GitHub): Hosts a PROTEUS-LIBRARY repository containing a pre-packaged MQ135-GAS-Sensor.zip. 🛠️ Installation Guide
Follow these steps to make the sensor appear in your Proteus component list:
Extract Files: Unzip the downloaded folder to find three core files: MQ135.LIB (or GasSensorTEP.LIB) MQ135.IDX (or GasSensorTEP.IDX) MQ135.HEX (The firmware required for the simulation model). Locate Library Folder:
Proteus 8: Navigate to C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\LIBRARY. (Note: ProgramData is often a hidden folder; enable "Hidden items" in Windows View settings).
Alternative Path: C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\Data\LIBRARY.
Copy and Paste: Move the .LIB and .IDX files into the LIBRARY folder.
Restart Proteus: If the software was open, close and reopen it to refresh the component database. ⚡ How to Use the Sensor in Simulation
Pick Component: Go to Component Mode, click 'P' (Pick from Library), and search for "MQ135". Set the HEX File: Place the sensor on the canvas. Right-click the sensor and select Edit Properties.
In the Program File field, click the folder icon and select the MQ135.HEX file included in your download. Wiring: VCC/GND: Connect to 5V and Ground.
OUT Pin: Connect to an Analog pin (like A0) on your simulated Arduino or microcontroller.
Test Pin: This is unique to simulation. Use a Logic State or Potentiometer on this pin to simulate changing gas concentrations during the run.
💡 Pro Tip: For accurate code development, you may also need the Arduino MQ135 Library to handle the calibration ( R0cap R sub 0 Rscap R sub s values) in your sketch. Gas Sensor Library for Proteus - The Engineering Projects
LIBRARY folder.Default paths:
C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\DATA\LIBRARYC:\Program Files\Labcenter Electronics\Proteus 7 Professional\LIBRARY