Tasmota Air Quality Sensor (PMS5003)

Build a WiFi-connected air quality sensor that measures particulate matter (PM1.0, PM2.5, PM10) using a Plantower PMS5003 sensor and a Wemos D1 Mini running Tasmota.

Why This Project

Health monitoring — PM2.5 is a key indicator of air quality affecting respiratory health
Indoor/outdoor — monitor both indoor air quality and outdoor pollution
Real data — much more accurate than most consumer air quality monitors
MQTT integration — automated alerts when air quality drops
Affordable — under $20 total

Components Required

Component	Purpose	Est. Cost
Wemos D1 Mini	WiFi microcontroller	$3
Plantower PMS5003	Particulate matter sensor	$12-15
PMS5003 breakout/adapter cable	Connects sensor to D1 Mini	$1
Optional: 3D-printed enclosure	Houses the sensor	Free

How PMS5003 Works

The PMS5003 uses laser scattering to count particles in the air:

PM1.0 — particles ≤1.0µm (ultrafine, penetrate deep into lungs)
PM2.5 — particles ≤2.5µm (key health metric, WHO guidelines)
PM10 — particles ≤10µm (dust, pollen, mold spores)

Reports both "standard" (factory environment) and "environmental" (real atmosphere) concentrations in µg/m³.

Wiring

PMS5003          Wemos D1 Mini
───────          ─────────────
VCC (Pin 1)  →   5V
GND (Pin 2)  →   GND
TX  (Pin 5)  →   GPIO14 (D5) — Tasmota RX
RX  (Pin 4)  →   GPIO12 (D6) — Tasmota TX (optional, for commands)

Tasmota Setup

Flash tasmota-sensors.bin to the Wemos D1 Mini
Configuration → Configure Module
Set GPIO14 to PMS5003 Rx
Optionally set GPIO12 to PMS5003 Tx (for sleep/wake commands)
Reboot — sensor data appears on the dashboard

Tasmota Template (Quick Setup)

{"NAME":"AQ Sensor","GPIO":[0,0,0,0,0,0,0,0,69,0,68,0,0],"FLAG":0,"BASE":18}

JSON Output

{
  "PMS5003": {
    "CF1": 2, "CF2.5": 4, "CF10": 5,
    "PM1": 2, "PM2.5": 4, "PM10": 5,
    "PB0.3": 540, "PB0.5": 150, "PB1": 20,
    "PB2.5": 2, "PB5": 0, "PB10": 0
  }
}

Air Quality Index Reference

PM2.5 (µg/m³)	AQI Level	Health Impact
0-12	Good	No risk
12-35	Moderate	Sensitive groups affected
35-55	Unhealthy (sensitive)	Reduce outdoor activity
55-150	Unhealthy	Everyone affected
150-250	Very unhealthy	Health alert
250+	Hazardous	Emergency conditions