A workshop PM2.5 monitor built by [WeSpeakEnglish] skips small screens entirely. The sensor output drives a large wall-mounted addressable LED seven-segment display PCB, making particle concentration readable from across a room.
The hardware is minimal by design: a Seeed Studio Xiao microcontroller sits on the back of the display PCB, connected directly to the particle sensor. The display color shifts as readings climb, and raw data streams over USB serial for logging. No separate enclosure, no extra board.
The full project repository is on GitHub and worth reading for the PCB layout decisions and the color threshold logic, not just the finished result. The Xiao-plus-large-seven-segment combination is also reusable for anything that needs a big, unambiguous number on a wall.
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