Measures multiple domains
Particulates, CO2, HCHO, VOCs, reducing gases, solvents, temperature, humidity, pressure. A fan and air flow chamber ensure accurate readings of the environment
Open Hardware
Airnode
Airnode is designed like a commercial IoT product. It fuses 9+ sensor modalities into a real-time environmental intelligence platform that computes, calibrates, and visualizes everything on-device.
MCUESP32-S2
DisplayIPS 2.8 240*320
FirmwareESPHome with custom C++ lambda
ModeOffline-first
Overview
What Makes It Special
A practical environmental node for local readings, diagnostics, and calibration state.
Interprets readings locally
Computes AQI-style scores and worst-case status without needing a cloud service.
Tracks calibration state
Uses clean-air gates, stability checks, and bounded baseline updates for MOS gas sensors.
Shows status on-device
Five screens cover live readings, gas detail, calibration, a quick guide, and system status.
Active-flow sensor chamber
A fan-assisted flow-through sensor chamber that gently draws air across the sensing elements for more consistent exposure and faster response.
Monitors its own health
A watchdog checks invalid sensor channels and airflow health so failures are visible.
Gallery
Photos
Exterior views of the enclosure, display face, ventilation, and installed hardware.
Supported sensors
Measurement channels
The payload combines reference sensors, gas sensors, and system telemetry.
| Parameter / use | Sensor | Human health relevance |
|---|---|---|
| PM1 / PM2.5 / PM4 / PM10Particulate counts plus VOC and NOx indices. | Sensirion SEN55 | Fine particles can reach deep into the lungs and are linked with asthma, cardiovascular stress, and long-term respiratory risk. |
| CO2Clean-air validation and occupancy signal. | Sensirion SCD40 | High CO2 usually indicates poor ventilation and can correlate with drowsiness, headaches, and reduced cognitive performance. |
| FormaldehydeHCHO monitoring in ppb. | Sensirion SFA30 | Formaldehyde is an irritant and known carcinogen; exposure can affect eyes, throat, and breathing comfort. |
| VOC / odorOrganic vapor, odor, toluene, H2S, and ammonia sensitivity. | Figaro TGS2602 | VOCs can trigger irritation, headaches, nausea, and sensitivity reactions, especially in enclosed rooms. |
| Solvents / ethanolAlcohol and solvent vapor detection. | Figaro TGS2620 | Solvent vapors can irritate airways and may affect the nervous system at higher concentrations. |
| Reducing gasesCO, H2, NH3, CH4, and related gases. | MiCS-5524 | Acts as an early warning channel for combustion and chemical events; CO and ammonia can become acutely hazardous. |
| Temperature / humidityReference channel for compensation. | Sensirion SHT3X/SHT4X | Comfort range affects sleep, respiratory comfort, mold risk, and how airborne pollutants behave indoors. |
| PressureBarometric pressure. | Bosch BMP280 | Not a direct pollutant, but useful context for environmental interpretation and weather-related comfort tracking. |
| Fan healthRPM monitoring for the sensor chamber. | Sunon Fan tachometer | Confirms sampled air is moving through the chamber so pollutant readings remain trustworthy. |
Calibration
Guarded baseline updates
The ESPHome script runs every minute, waits for warmup, checks clean-air references, accumulates stable Rs samples, then updates Ro baselines.
Clean-air thresholds450 ppm / 120 VOC / 5 PM2.5 / 30 ppb
Stability window5 min, CV <= 5%
Ro update70% candidate / 30% stored
Display
Local screens
The device remains usable without opening an app or dashboard.
Controls
Hardware interface
Two buttons handle display brightness and page navigation.
Brightness cycle
Cycles six PWM backlight levels from full brightness to low-light mode.
Backlight toggle
Turns the TFT backlight on or off.
Next screen
Cycles through the five dashboard pages.
Files
Project resources
Make one yourself, everything is available on printables.