Mika's Seeed Studio XIAO ESP32C3-Powered Air Quality Monitor Packs Sensirion, Winsen Sensors
Compact 3D-printed housing delivers true carbon dioxide level, VOC, relative NoX, and PPM readings.
Mononymous maker Mika has released production files and source code for a work-in-progress compact air quality monitor, driven by a Seeed Studio XIAO ESP32C3 connected to the Sensirion SEN55 and Winsen Sensor MH-Z19C environmental sensors — all housed in a neat 3D-printed case.
"[The air quality monitor] uses a custom PCB designed by me, as well as a SEN55 sensor, and a MH-Z19C sensor," Mika explains. "The PCB is designed around the [Seeed Studio] XIAO ESP32C3, but something like am [Espressif ESP32-C3] Super Mini will also work, though you'll have to adjust the pinouts in code."
The air-quality monitor, dubbed the M-IAQ, is designed for indoor use, and uses its paired Sensirion and Winsen sensors to deliver true carbon dioxide readings up to 2,000 parts per million (PPM), volatile organic compound (VOC) concentrations, relative nitrogen oxide (NoX) concentration, and PM1, PM2.5, PM4, and PM10 particular matter concentrations. In addition to wireless connectivity for data logging and reporting, there's room for an OLED panel for live readouts.
"The SEN55 also has an internal temperature and humidity sensor, but especially the temperature sensor is really not that accurate," Mika warns. "You can still use it if you want to. I have the SEN55 mounted with some strong double sided tape, and the MH-Z19C is mounted with zip ties. Feel free to make a more elegant solution for this."
The project is documented on GitHub, alongside Gerber files for the PCB, 3D models for the case, and source code for the firmware, all made available under an unspecified license.