Build a Low-Cost Air Quality Sensor with ESPHome
A DIY air quality monitor built around an ESP32 and a modern particle sensor is one of the highest-value home automation projects you can complete in a single afternoon. Connect a PMS5003 or the newer Sensirion SEN66 to an ESP32, flash ESPHome , and within minutes Home Assistant discovers the device over your local network — no cloud account, no monthly fee, no privacy concerns.
Why Monitor Air Quality at Home?
Most people think of air pollution as an outdoor problem. The reality is that indoor air quality is frequently worse. Cooking on a gas stove, burning candles, running a laser printer, using cleaning sprays, or simply having new furniture off-gassing formaldehyde can push indoor particle and chemical concentrations well above outdoor levels for hours at a time.







