RealisticPM: Room PM2.5 Wall Display

RealisticPM is an open-source, wall-mounted air quality monitor that shows fine-particle (PM2.5) concentration on a large, easy-to-read color display. It’s meant to make invisible air pollution visible at a glance in offices, workshops, gyms, and clean rooms.

The device is built around the Seeeduino XIAO SAMD21 and powered from a standard USB-C connector, drawing no more than 2 W. The display uses high-quality addressable LEDs, so the color changes automatically with air quality, and brightness adjusts on its own to suit the room. Readings are shown in steps as fine as 0.1 µg/m³.

For tinkerers, the board streams data over a virtual COM port and exposes a pin-out for further development. A resettable fuse protects the electronics. The full enclosure measures 364 × 164 x 18 mm.

Firmware (Arduino), PCB assembly files, and mechanical designs are all available on GitHub.