Toxic Gas Detector




Hi everyone my name is Andrew, and this is my recent project. It was about detecting toxic gases inside our car. So, the main part of this device is a VOC sensor. It was used to detect the density of toxic gases in the air. With the changing of density, The sensor's resistance changes to. Higher the density is, lower the resistance is. And that is how it works.

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Step 1: Materials

1. Arduino Uno

2. MQ-135 Gas Sensor

3. OOTDTY 4 Bits Digital Tube LED Display Module

4. Lcd 1602 Module

5. Passive Buzzer Module 5V

6. PVC box

Step 2: Tools

1. Laser cutter

2. Hot glue gun

Step 3: Making PVC Box

1. Create a scheme of your box or use mine (link). Dont forget to cut out holes for mounting sensors and modules later. You need 6 pieces for 6 sides of the box.

2. Use laser cutter to cut it out.

3. Use a hot glue gun to stick 5 sides together. The 6th one will be a lid so you can open and close it.

Step 4: Assembly

1. Upload the code, using arduino software. You can use mine ( download it from here), or write your own.

2. Connect all modules and sensors to our arduino according to the circuit.

3. Put everything inside the box and mount sensors and modules using hot glue gun.

Step 5: Tests

I have tested in some old cars, and the results are not actually making much difference. Nevertheless it still succeed

Step 6: Program Code



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    6 Discussions


    2 years ago

    That's neat :) It would be helpful with older cars.

    1 reply

    2 years ago

    Fill the car with exhaust gas and then test . Remember not to get in or not as your choice .

    You forgot to load the code you used

    1 reply

    Reply 1 year ago

    advice accepted but filling with exhaust is not a easy and we don't really have someone who is willing let us fill his car with exhaust XD, and my code is now uploaded, thanks for noticing me


    Reply 1 year ago

    its resistance changes through the density of hydrogen (doesn't really matter), methylbenzene (a lot on decorations inside cars, also pretty harmful, can cause a series of uncomfort like headache or regurgitation etc.) and ammonia (harmful but not familiar with cars)