When I sit at my living room table I can see wonderful big airplanes in the final approach to Zurich (ZRH) airport or ascending to a far destination: Airbus A380 or Boeing B777 are ingenious proof of what we are capable to design and build. Quite often when I have visitors I start flightradar24 to get more information about the airplanes we see. But wouldn’t it be nice if this information would just be there, anytime I’m curious – without starting an app on my smart phone? Since I’m playing a lot with the ESP8266 it was an obvious choice to build such a device by myself. I actually had already built one a while back with the Flight-O-Matic but the setup was quite complicated and the project was dormant for a while. Until I recently discovered a service that provides exactly the information I needed and is free to use as well.



What you’ll need

In order to get this project running you’ll need the following list of hardware:

Depending on the coverage of adsbexchange.com feeders in your area you might also buy the following items:

Raspberry Pi (Model 3 recommended but also works with older versions and probably Zero)

RTL-SDR dongle for receiving the ADS-B signal

Micro SD card for Raspberry Pi (for Model 3 or with adapter, depending on your RasPi model)

The Service – ADSBExchange

At the core of this project is the excellent service provided by Dan Streufert and countless people feeding live transponder signals into it: http://adsbexchange.com. From what I understand it is built on top of the http://www.virtualradarserver.co.uk/ project and lets you query live position data based on location, distance to a point, altitude etc and returns a JSON object which you can process in your code. Please note: in order to keep this service free-to-use Dan depends on your support, either by donating money to cover the server hosting costs or by providing your local data to improve coverage.

Note, this step is optional: When I first checked the coverage of the Zurich airport wasn’t so great so I decided to reactivate my RTL-SDR DVB-T dongle (see posts here, here and here) and contribute live data to adsbexchange.com. If the coverage in your area is insufficient consider to setup such a feeder as well.

Once you have the hardware (see above, Raspberry Pi and RTL-SDR dongle) you can either do the setup manually or take a short cut by becoming a flightaware feeder and using their ready-to-feed sd-card image called PiAware: http://flightaware.com/adsb/piaware/install. Once you have done that you have to setup your PiAware instance to also feed to adsbexchange.com by running a script provided by Dan: http://www.adsbexchange.com/how-to-feed/

The Plane Spotter Hardware

Once you are sure you have a good coverage of your area of interest you can start to get to the actual plane spotter hardware. I recommend to either use the components provided by my IoT Starter Kit or to get the setup I described in this post using the Wemos D1 Mini which requires soldering but yields a very compact setup. The wiring is described here.

The Code

UPDATE: this section describes the Platformio IDE project setup. In the meantime I have made it available also as example project in the WeatherStation library. Read more about it here if you prefer the Arduino IDE.

In my recent ESP8266 projects I started switching to the PlatformIO IDE since it is a lot more convenient to use compared to the Arduino IDE: automatic library dependency management, better coding support in the editor and great Travis CI and even Continuous Delivery support. So please make sure that you have a running IDE before you get started with the code. Once you have that ready please checkout the code from my github repository.

Now the most important part is to configure the QUERY_STRING variable in the main.cpp file:

const String QUERY_STRING = “lat=47.424341887&lng=8.568778038&fDstL=0&fDstU=10&fAltL=0&fAltL=1500&fAltU=10000”;

For a detailed description please checkout the documentation of the virtual radar server. What my example does is to filter out all aircrafts which are not within 10km from a location south of the runway and above 1500 feet (I don’t care about landed airplanes) or above 10000 feet (I also don’t care about transit airplanes). There are many options to adapt this query to your needs, so please carefully read the afore mentioned documentation. Once you are ready with the query you can flash the firmware on your ESP8266 chip.

First Run & Adapting it

Since the ESP8266 is fetching the data from the internet you’ll have to connect the module to the internet. My code is using the excellent WifiManager library. If your ESP8266 cannot connect to a (known) access point it will start an AP by itself and allow you to connect through your Wifi settings to it. A captive portal window opens and lets you select the correct SSID and enter the password. It then stores the Wifi settings on flash and will use it in the future.

If everything works you can go on and change the way the data is displayed or extract more data from the adsbexchange json object. It would be great if you could share your results with me either here in the comments or on Twitter. I’ll be happy to share it with the community.

Summary

You can build a cute little plane spotting tool with just a few components for under $20 without much work. If the coverage of your area on adsbexchange is poor then you could become a data feeder for about $50.- more (Raspberry Pi + RTL-SDR Dongle). Playing with the real-time data is fun and can be a very rewarding weekend project!