SpacePC Airstation documentation

The SpacePC Airstation is a compact indoor air-quality monitor based on the Sensirion SEN66 and an ESP32-P4 with a 4.3-inch touch display. It continuously measures CO₂, PM2.5, PM10, VOC Index, NOx Index, temperature and relative humidity and presents the readings directly on the display.

Air-quality measurement and display do not require Wi-Fi or internet access. Wi-Fi is optional and enables automatic time synchronisation and local Home Assistant integration through the SpacePC integration.

Required hardware

• 1 × SpacePC Airstation Kit – includes the matched display controller, Sensirion SEN66, connection cable and mounting screws; optionally available with the 3D-printed enclosure

A suitable regulated 5 V USB-C power supply is required for operation.

Connect the sensor

The Sensirion SEN66 connects directly to the ESP32-P4 display through I²C. Disconnect power before making or releasing any connection.

Wiring

• SEN66 3.3V / VDD → display 3V3 – power

• SEN66 GND → display GND – ground

• SEN66 SDA → display SDA – I²C data

• SEN66 SCL → display SCL – I²C clock

No additional data lines or electronics are required. Connect SDA to SDA and SCL to SCL. After connecting the sensor, power the display through USB-C.

Install firmware with the Web Flasher

Install the Airstation firmware directly in the browser without Arduino IDE. You need a desktop computer, a Chromium-based browser with Web Serial support and a USB-C data cable. Charge-only cables may power the controller but cannot be detected by the Web Flasher.

1. Connect the ESP32-P4 display to the computer with a USB-C data cable.

2. Open https://spacepc.dev/en/flash in a supported browser.

3. Select SpacePC Airstation.

4. Choose “Install firmware” and select the matching serial port.

5. Confirm the installation and wait approximately two minutes.

6. Do not disconnect the USB cable or close the browser window during installation.

7. After the success message, the Airstation restarts and is ready for initial setup.

The SpacePC Web Flasher obtains the required flash offsets and files automatically from the published firmware manifest.

Initial setup

1. Disconnect power.

2. Connect the SEN66 to the display.

3. Check all connections and connector orientation.

4. Connect USB-C power.

5. Wait for the Airstation to start and initialise the SEN66.

6. Confirm that the first readings appear on the display.

Some readings need time to stabilise after startup. Wi-Fi is not required for normal operation.

Touch controls

Tap a reading to open its detail view and graph. Swipe left for the next view and right for the previous view. Swipe down from the top edge to open network and device settings.

Wi-Fi and time synchronisation

All measurements, touch controls, the local display, graphs and stored trends work without Wi-Fi. When connected, the Airstation can synchronise its clock automatically over the network.

Home Assistant

The optional SpacePC Home Assistant integration discovers the Airstation locally over mDNS when both systems can communicate on the same network. Manual IP entry is normally unnecessary.

Home Assistant receives entities for CO₂, PM2.5, PM10, VOC Index, NOx Index, temperature and relative humidity. The integration operates locally and requires neither an MQTT broker nor a cloud account. Follow the separate SpacePC Home Assistant integration documentation for installation.

Understanding the readings

CO₂

CO₂ is shown in ppm and is particularly useful for evaluating room ventilation. Concentrations normally rise when people spend time in a closed room. The Airstation highlights this value and can recommend ventilation when it is elevated.

PM2.5 and PM10

PM2.5 represents fine particles with an aerodynamic diameter up to 2.5 µm; PM10 covers particles up to 10 µm. Both are shown in µg/m³. Cooking, candles, dust, smoke, outdoor air and other particle sources can affect the readings.

VOC Index

The Sensirion VOC Index indicates changes in volatile organic compounds associated with sources such as cleaning products, perfume, furniture, paint and cooking. It is an index, not the concentration of one specific chemical compound.

NOx Index

The Sensirion NOx Index indicates changes associated with nitrogen oxides and corresponding oxidising gases detected by the sensor. It is likewise an index rather than a concentration for one specific compound.

Temperature and humidity

Room temperature is shown in °C and relative humidity in percent, allowing the Airstation to serve as a thermometer and hygrometer as well.

Dashboard and trends

The main dashboard presents CO₂, PM2.5, PM10, VOC Index, NOx Index, temperature, humidity, sensor status, Wi-Fi status and time. Tap a reading to see whether it is rising, falling, stable or changing suddenly. The CO₂ graph can show the effect of opening a window.

Placement

Place the Airstation where normal room air can circulate, such as on a desk, shelf, sideboard, bedside table or workspace. Keep all enclosure vents clear.

Avoid positions directly beside a fan, air conditioner, open window, door, radiator, strong heat source, cooking area or direct sunlight. Direct airflow can make the sensor measure air from one source rather than representative room air.

Enclosure and power

The optional 3D-printed enclosure holds the ESP32-P4 display and SEN66 while protecting the electronics. Do not obstruct the sensor inlet or outlet. Power the device with a suitable regulated 5 V USB-C supply; no mains voltage is present inside the enclosure.

Cleaning

Clean the display and enclosure with a dry or slightly damp soft cloth. Do not allow liquid through the ventilation openings. Never clean the SEN66 with water, alcohol, aggressive cleaning agents or compressed air, and do not touch or mechanically clean its openings.

Troubleshooting

Display remains dark

Check the USB-C cable, power supply and connector. Test a known-good regulated 5 V supply and cable.

No readings or sensor not detected

Disconnect power and verify 3.3V → 3V3, GND → GND, SDA → SDA and SCL → SCL. SDA and SCL must not be reversed. Restart afterwards.

Readings change slowly

Check for blocked sensor or enclosure openings and move the Airstation away from unsuitable locations.

CO₂ differs from another monitor

Different sensors and positions can produce different readings. Place comparison devices close together and allow both to stabilise.

Temperature appears too high

The display and controller generate heat. Ensure sufficient airflow around the SEN66 and keep it away from internal heat sources.

Wi-Fi is unavailable

Air-quality measurement continues normally. Only automatic time synchronisation and Home Assistant integration are unavailable.

Airstation is not discovered by Home Assistant

• verify the Airstation's Wi-Fi connection

• ensure both systems share a network that permits local HTTP and mDNS

• install and enable the current SpacePC integration

• rule out guest-network isolation, client isolation and blocked multicast traffic

Safety

• Check wiring before applying power.

• Do not reverse 3.3V and GND.

• Connect SDA and SCL correctly.

• Use only a suitable regulated 5 V USB power supply.

• Use the device only in dry indoor locations.

• Keep liquids out of the enclosure.

• Do not cover ventilation openings.

• Do not expose the sensor to liquids, cleaning agents or compressed air.

• The Airstation is not a calibrated safety, smoke, fire or gas-warning device.

Technical architecture

The Waveshare ESP32-P4-WIFI6-Touch-LCD-4.3 handles the user interface, touch input, processing and storage of readings, graphs, Wi-Fi, time synchronisation and Home Assistant communication. The Sensirion SEN66 measures CO₂, PM2.5, PM10, VOC Index, NOx Index, temperature and relative humidity and sends the values to the display over I²C.

The Airstation therefore works either as a completely standalone touch-display monitor or optionally as a local sensor within Home Assistant.