What is this project about?

Visit the General Questions section to find out who we are, what the project is about and what we measure.

What exactly is the sensor?

General information about the sensor – what it is, the data it broadcasts, the connectivity in your house in the “About your station – General” section.

How can I participate?

To find out about the different ways of participating and how this works, visit the “About Your Participation” section.

Technical questions about the station

Only for the advanced – if you want to find out about the software code and more, check in the “About Your Station – Technical” section.





  • How do I get into the station controller and manage / change the settings?

    If the sensor has established a Wi-Fi connection, you can only connect through the network. As an address, you can use the IP address of the sensor that you will find by logging into your home router.

    Alternatively, the sensor supports access to http://feinstaubsensor-{sensorID}.local/. Where sensorID is your individual number with which you registered your sensor with us.

    This address is not supported by any operating system without additional software! It should work seamlessly under MacOS, Linux (via Avahi service) and current versions of Windows 10. If Apple iTunes or Skype are installed, it also works under Windows 7. With Apple’s , you install only one 5MB file and then you can access the address.

  • How do I see the program code of the controller, API server, and map?

    The sensor’s Firmware:

    You can find the API software at:

    The software on the map can be found on:

  • How can I access other data from my sensor station?

    Data from the last 5 minutes of a particular sensor -> , where sensorID = the individual sensor station number you got when submitting confirmation from us

  • How can I access other data from all stations?

    You can find the data from all the sensor stations in * .csv format at

  • How do I mount the station?

    Make sure the station:
    – is fixed and stable;
    – it is not installed in a closed room;
    – is not exposed to direct sunlight;
    – is not on the inside of the balcony and has enough free space below it;
    – do not smoke nearby, do not prepare a grill nearby;
    – no close incidental household pollutants.

  • How to register the station?

    After you assemble your adopted station in one of the labs, we will give you an address to register it with. If you have purchased parts yourself and assembled your station, you will need to send us its ID, coordinates and installation photos at

    You can also register your station directly at the following address – Beforehand, make sure your station is operational and meets the assembly and installation requirements.

  • Troubleshooting Guide

    Important requirements:

    • Never press the Reset and Flash buttons on the controller. This may delete the controller’s pre-recorded firmware.
    • Do not apply force to the pins of the controller. Their distortion or breakage will make the station unusable
    1. You received a broken station by courier.
      – Shoot a broken station
      – Send by courier back to the foundation, remembering to note the shipment number you received the station with and the station ID.
    2. After initially turning on, you do not see the station, despite the urgent search and scan for available networks. – Possible cause and remedy:
      – Malfunctioning power supply unit – Replace with an available power supply or battery with a USB output and a power rating of at least 1A. After connecting the station to the network, make sure that there is a hum from the fan rotation of the PM sensor. If the buzz is heard, the station should be visible.
      – Malfunctioning power cord – Replace the power cord with the available USB port and micro USB port. After connecting the station to the network, make sure that there is a hum from the fan rotation of the PM sensor. If the buzz is heard, the station should be visible.
      – There is a fault in the controller – open the station (when off) and check that the blue diode of the controller flashes 3 times when switched on and then goes out. If it does not flash and you have checked everything described above, the fault is in the controller. If it is blinking, then the controller may flash.
      – The station has already connected to a previously entered network – Check at the following addresses whether the station is broadcasting. NUMBER-bme280 NUMBER-sds011
    (Replace the NUMBER with your station ID.)

    Wait for 3 minutes, then check that there are values ​​in the charts of the specified addresses. If there are values, it is likely that the station has connected to any available network that was previously introduced. If there are no values, the station does not broadcast.

    3. After connecting the station to the home network, one of the sensors at one of the following addresses is not visible: NUMBER-bme280 NUMBER-sds011
    (Replace the NUMBER with your station ID.)

    Possible cause and remedy:

    – Sensor cable connections disconnected – check that no sensor or controller cable has been disconnected. If necessary, remove and re-insert the cables into the pins of the sensor and controller.
    – Sensor cable connections broken – If the cable connections are pulled out when shaking any of the controller or sensor pins, then rotate the cable 90 g or replace it with a new one.
    – Incorrect station configuration – Enter station settings and check for ticks in front of both SDS011 and BME280 sensors. There should be no ticks in front of the other sensors.
    – Sensor cold soldering – Inspect the BME280 sensor for possible cold soldering. If possible, remove it.

       4. The PMS sensor – SDS011 shows very high values. – Possible cause and remedy:
    A. Clogging the sensor from dust or other particles – remove the hose and try blowing the sensor with air. If the sensor’s operating mode does not change then, it may be necessary to replace the sensor.
    B. Defective or poorly calibrated sensor. – Sensor replacement required.

     5. PMS Sensor – SDS011 shows very low values. – Possible cause and remedy:
    A. Clogging of the sensor by bugs, solid objects, etc. Remove the sensor hose and flush it. Check the airflow of the sensor for a bug or particle to block the fan and the airflow.
    B. Defective or poorly calibrated sensor. – Sensor replacement required.

     6. The BME280 atmospheric sensor does not display normal values. – Possible cause and remedy:
    A. Sensor cold soldering – Inspect the BME280 sensor for possible cold soldering. If possible, remove it.
    B. Defective or poorly calibrated sensor. – Sensor replacement required.

    7. Connection after entering the wrong password on the home WIFI network.
    A. Turn off the station.
    B. Turn off the router to which the password is incorrect.
    C. Make your second Hotspot (WIFI hotspot) with an elementary password. For Android, HotSpot is about the features of “providing connections and networks.” Remember the password.
    D. Turn on the station again. It will start broadcasting the Feinstaubsensor-NUMBER (because the last router is missing).
    E. Connect using the first telephone to the Hotspot station – Observe point I of this instruction. When the second phone shows that a device is already tied to it, stop it (the second phone)!
    F. Turn on the router again.
    G. Restart the station. It will remember the Hotspot, but it is gone because you stopped the second phone

    8. How to perform annual station maintenance:
    Usually the annual maintenance of the station is carried out before the start of the heating season. See in detail the procedure for performing it.

    9. How to check / diagnose the station?

    1. Online check

    • Do they see data online (madavi API)?
        • You can also search for [ID] in the text at or here:
      • Is the sensor registered at and sending data to the main API (map visibility)?
      • See if the WiFi signal level was a little low / desirable to be above 30%:
      • Here’s the server-side log: [ID]

    2. USB Cable Check – Advanced only!

    • Check the power: USB cable – Make sure it is not interrupted anywhere, especially where it passes between window frames or doors. If possible, try another USB cable.
    • Restart (power outage, eg pull the USB plug)
    • Is the WLAN configuration good (the sensor connects to the configured WLAN)? If not:
      • Does the sensor open the AP (in the first 2-7 minutes after restart)?
      • Search for WLAN airrohr- [ID]. Patience may take 1-2 minutes after the restart.
        alternatively you can use the Discovery mode of the Flasher app.
      • Check on your own router that the sensor is registered to the network, then find the IP address of the station. This step is performed only after the initial connection of the station to the router.
      • If registered: connect to IP through browser http: // [IP] /. The interface should appear there.
      • If not: ESP has problems, e.g. power is not enough, continuous restart, incorrect network password, or the like.
    • Connect the USB to your computer and browse the log there. This step is possible at any time after the initial flash of the controller.
      • Serial Interface Text Tracking with Serial Terminal Program (Settings: baud 9600, 8N1)
        • for Linux: screen, minicom, cutecom;
        • for Windows: Tera Term, PuTTY;
        • for macOS: screen, minicom, Serial, …
        • Appropriate USB drivers may be required, see
      • There you should be able to see what the sensor does (charging messages, WiFi connection or AP, measurement – only in 3 minutes)

    3. Regarding electronics:

    • Remove the sensor electronics from the chassis and monitor after the power is connected.
    • Check / replace the power supply again
      • Does ESP blink shortly after restart? – If it does not flash – ESP may be damaged.
      • Does the SDS011: red LED / fan turn on / briefly after restart? – Check the connection for disconnected cable. Check the wiring diagram.
      • Check / replace the cables to the sensors.