I made this Air Quality / Climate sensor from a retired Pneumatic Tube for my partner, who saved it from going to the hospital bins at her work!
- It measures CO2, particulate matter (1, 2.5 and 10 µg/m³), temperature, and humidity
- It makes various beeps and flashes when various air quality thresholds are exceeded
- It has a number of different screens showing details of each measure (and happy/sad faces etc), which it automatically shows when an alert is triggered
- It has a DND mode to silence it at night
- It scans for our smart fitness bands via Bluetooth Low Energy (BLE) and makes special beeping noises and welcomes when it sees we have arrived home (for fun)
- It has a 3d printed ‘cage’ which replaces the original transparent acrylic to help with sensor ventilation
- It was supposed to be able to operate off battery for a while too, but it I discovered during implementation that the micro-controller won’t output 5V when on battery (only 3.3V), the PM2.5 and CO2 sensors need 5V, and I didn’t want to step up the voltage… so I just removed the 18650 battery.
Here’s some of the key parts. It’d aIl ESPHome on an ESP32 of course😉. I generally went with decent quality sensors rather than some of the cheaper options.
