This project was submitted to the Hackster.io and Helium hackathon #IoTforGood competition. Our code can be found here on github.
We will be using the MQ-135 Air quality sensor. It can detect NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc.
Doing a quick test by burning a paper towel near the sensor, we can see that Carbon Monoxide (CO) has the highest concentration of detection (as expected), so we’ll use that to monitor for smoke. We’ll start our project off by setting an arbitrary trigger level of 50 PPM, which we’ll use later in our Cayenne dashboard to alert us of smoke.
source: https:// parleylabs.com/2020/07/08/air-quality-fire-detection-using-the-helium-network/