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.
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