What is ADS-B? It’s what the airplanes speak!
Automatic Dependent Surveillance — Broadcast (ADS-B) is a protocol used by aircraft for transmitting their location and other information to other aircraft and to air traffic control. ADS-B is transmitted on 1090MHz via a pulse position modulation protocol called Mode S, and has become an internationally adopted standard over the decades since it was originally introduced.
Because the protocol is unencrypted, aviation buffs have created numerous hardware and software solutions for decoding, saving, and sharing ADS-B data from around the world. Aggregators for this data include community websites like airplanes.live and businesses like FlightAware and FlightRadar24. ADS-B data gets used for everything from airline route planning to air crash investigations to tracking Elon Musk’s jet. It’s also used for academic studies, like validating global weather models using aircraft wind data or mapping GPS spoofing and jamming incidents around the world.
Most of the ADS-B data on community exchanges is received and uploaded to the internet by a network of thousands of community-maintained ground stations. These are usually based on a Raspberry Pi single-board computer connected to one or more software defined radio (SDR) dongles that are used to receive the 1090MHz ADS-B signal. Decoding on these stations is done with an open source software decoder called dump1090, which extracts ADS-B messages from the raw I/Q data stream provided by the SDR.
Meet ADSBee
OK, so what is ADSBee? I started the ADSBee project to make small, low-power ADS-B receivers more accessible and open source. Most existing open designs use the aforementioned SDR dongles and external compute device, making them rather bulky and power hungry, and less well suited to embedding into drones, portable battery-powered devices, or other embedded projects. Commercial off-the-shelf ADS-B receivers exist, but most are based on rather expensive FPGAs and cost $350 or more. ADSBee is an open source project that uses a new demodulator that I designed to enable ADS-B decoding in a small, low-power, and low-cost device.
With a novel demodulator based on the RP2040 microcontroller and its PIO peripherals, the ADSBee 1090 board provides commercial-grade ADS-B decoding without the need for an FPGA or external compute. This makes it affordable enough to integrate into a wide variety of projects, while still having low power draw (about 1W) and a small footprint. ADSBee can provide aircraft data over a variety of interfaces, including USB, UART, Wi-Fi, and Ethernet (with an accessory board). This makes it easy to send aircraft data to anything from tablets to online databases to drone autopilot flight computers.
Open Skies
The best part about the ADSBee project is that it’s open source! Unlike ADS-B aircraft transponders, which are subject to a strict certification regimen, there are no certification standards for portable ADS-B receivers (those not permanently installed in full-size aircraft). This means that commercial receivers, despite their high price tag, use proprietary closed source firmware and hardware that can be slow to evolve and sometimes contain bugs that can lay hidden for years.
By open-sourcing the receiver schematic and firmware, ADSBee has drawn upon a supportive community of beta testers to squish bugs fast and incorporate everyone’s best ideas. ADSBee users have proposed improvements ranging from helpful new configuration commands to improved aircraft position filtering algorithms, and it seems like every time ADSBee is baked into a new application, a flurry of new ideas is quick to follow.
Bee Beta
The ADSBee project is 2 years old and has been in a beta phase since late 2024. Since the beta units were released, firmware features have been added and improved based on user feedback.
Most recently, in July 2025 we rolled out new dual-band capable hardware in the form of the ADSBee 1090U, which includes an additional radio and microcontroller in the same form factor PCB. While the original ADSBee 1090 decodes ADS-B packets sent on the standard 1090MHz frequency, about 5% of aircraft in the United States transmit ADS-B on a separate frequency band of 978MHz, using a protocol called UAT (Universal Access Transceiver). The new dual-band ADSBee can receive messages from aircraft operating on both frequencies simultaneously. It could even be used to decode other aircraft protocols in the future.
Pants Drop!
More new ADSBee-powered hardware is in the works! Accessory boards for the ADSBee were originally going to be called “hats,” but beta testers insisted they be called “pants” after the name of my small business, Pants for Birds LLC.
So, a PoE pant (for connecting and powering an ADSBee over Ethernet) is already in production, and plans are being made for a GNSS pant (adds a GPS receiver for real-time receiver positioning data) and a battery pant (for portable operation without a USB cable).
The ADSBee connects to pants via standard 0.1"/2.54mm pin headers, so it’s easy to create a custom pant using simple protoboard. Future firmware updates will include custom GPIO functions to enable custom pants for activities like battery voltage sensing or charge control. This image shows an ADSBee 1090U with a PoE pant in a 3D-printed enclosure, ready to be mounted in an attic for optimal reception!
And for projects with tighter requirements, the single-band ADSBee m1090 solder down module can be directly integrated into PCBs. We’re excited to see what people will build with it!
Building With the Bee
I am continuously surprised and delighted by the projects that people are cooking up with their ADSBees. I’ve seen PoE and solar-powered ground stations, beautiful LED displays of aircraft in the area, portable handheld receivers, and ADSBees directly integrated into drone autopilots, for traffic alerting and miniature cockpit displays.
Here are a few projects from our beta testers:
ADSBee on an FPV Airplane
Petr Čada, Czech Republic
Petr integrated an ADSBee into his T1 Ranger first-person-view (FPV) R/C aircraft. Air traffic data from the ADSBee is reported to the flight controller over the MAVLINK protocol, and gets added to the pilot video feed as part of the On-Screen-Display (OSD) overlay. This image shows an aircraft being detected by the ADSBee while it flies a few thousand feet overhead (both the UAV and the passenger aircraft are operating in approved areas). The airliner can be seen in the center top of the frame, below the distance to home indication.
14-Segment Flight Display
Steve Mo, California
Steve put together a beautiful 14-segment display that reads aircraft data from the ADSBee and shows information about nearby aircraft (see it on page 60). The display cycles through each of the aircraft within range and displays latitude/ longitude, altitude, vertical rate, airspeed, and heading. This device was lovingly crafted with some SMT work and a lot of through-hole hand soldering. The display is powered by an STM32F103 microcontroller running custom firmware that reads aircraft data from the ADSBee via MAVLINK1 and a UART connection.
Solar/Battery ADS-B Ground Station
Ryan Null, California
Ryan wanted to mount an ADSBee on the roof without a PoE cable run, so he designed a solar- and battery-powered base station.
The ADSBee’s low power draw allows it to be powered with a relatively small solar panel and LiPo battery bank, even in partial shade. Ryan is now working on adding a larger panel, MPPT tracker, and larger battery to enable his ADSBee to last through the dark winter months.
Ryan’s ADSBee connects to a Wi-Fi network to feed air traffic data from the surrounding area. Beta testers are excited about using larger external Wi-Fi antennas with improved directional gain to enable solar/battery receivers to be mounted further from their Wi-Fi networks, in spots with better ADS-B reception or longer hours of sunlight.
FPVToys Cockpit Display with ADSBee
Jeff Hendrix, Colorado & John McNelly, California
Jeff makes miniature cockpit flight displays for R/C aircraft that are fully functional! He recently added an ADS-B moving map display that renders live air traffic and runways of nearby airports onto a miniature instrument panel. This was so cool that I had to put together a miniature cockpit to show it off at Open Sauce, with Jeff’s help on the electronics. The shell is 3D printed, with the screens mounted from the inside. An ADSBee sits in the back and is connected to 1090MHz and 978MHz antennas. The map can be scrolled around using a custom keypad. Open Sauce attendees were shocked to see the gauge cluster come to life when they picked up the instrument panel from the display table!
The instrument panels and controller are from Jeff’s business, FPVToys.net. He recently released a firmware for the display controller that is compatible with ADS-B input from an attached flight controller. I’m excited to see ADSBee-equipped mini cockpit displays taking to the sky!
Now Boarding
Makers are coming up with new ways to use ADSBee every week. On our Discord server, beta testers can share projects and ask questions. Our monthly email newsletter brings you firmware updates, cool new projects, and adventures in manufacturing open source hardware. We’d love to have you along for the ride.
Resources
Photography by John McNelly except where noted.
This article appeared in Make: Volume 95.
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Facts Only
* ADS-B is a protocol for aircraft to transmit location and information.
* ADS-B is transmitted on 1090MHz via Mode S pulse position modulation.
* Community aggregators include airplanes.live, FlightAware, and FlightRadar24.
* Ground stations use Raspberry Pi and SDR dongles to receive the 1090MHz signal.
* The dump1090 software extracts ADS-B messages from raw I/Q data.
* ADSBee uses a novel demodulator based on an RP2040 microcontroller for decoding.
* The ADSBee 1090 board provides decoding using the microcontroller instead of FPGA or external compute.
* ADSBee can provide aircraft data over USB, UART, Wi-Fi, and Ethernet.
* The ADSBee 1090U supports receiving on 1090MHz and 978MHz (UAT).
* Future hardware includes PoE pants and GNSS pants accessories.
* Projects include an ADSBee integrated into FPV aircraft and a solar/battery ground station.
Executive Summary
Automatic Dependent Surveillance — Broadcast (ADS-B) is a protocol aircraft use to transmit location and other information to other aircraft and air traffic control. This data is transmitted on 1090MHz using a Mode S pulse position modulation protocol. The unencrypted nature of ADS-B has led to community-developed hardware and software for decoding, with aggregators like FlightAware and FlightRadar24 utilizing this data for applications ranging from route planning to investigations.
The raw ADS-B signals are typically received by thousands of community ground stations built using hardware like Raspberry Pi connected to Software Defined Radio (SDR) dongles, employing decoders such as dump1090 to extract the messages from the I/Q data stream.
The ADSBee project aims to make low-power ADS-B receivers accessible by using a novel demodulator based on an RP2040 microcontroller, enabling commercial-grade decoding without requiring expensive FPGAs. This results in a small, low-power, and low-cost device that can interface via USB, UART, Wi-Fi, or Ethernet.
The project emphasizes open-source principles by making the receiver schematic and firmware available, allowing the community to rapidly improve performance through contributions. Recent developments include the dual-band ADSBee 1090U, which allows reception on both 1090MHz and 978MHz (using UAT), and planned accessories like PoE pants for power and GNSS pants for positioning data.
The project has evolved through a beta phase, incorporating user feedback to enhance features, and ongoing development involves new hardware and accessory designs aimed at embedding the technology into diverse projects.
Full Take
The narrative centers on the tension between proprietary, closed-source aviation standards and the open, community-driven development of surveillance technology. The core pattern involves leveraging publicly broadcast data for widespread utility—from commercial tracking to academic research—which exists outside of official regulatory channels. The shift from proprietary, expensive hardware in commercial receivers to an open-source, low-power design like ADSBee highlights a friction point between established certification regimes and decentralized innovation.
The development trajectory suggests a pattern where perceived limitations of existing systems (cost, inflexibility, proprietary lock-in) are systematically addressed by community-driven reverse-engineering and open-sourcing. The introduction of new hardware iterations, such as the dual-band capability in ADSBee 1090U, demonstrates an iterative process of expanding functionality based on user needs rather than rigid regulatory mandates.
The ecosystem relies on a feedback loop where practical applications—like integrating data into FPV flight systems or designing portable ground stations—drive feature additions and hardware enhancements. The promise of open source is not just about access to schematics but about establishing a resilient, self-correcting system where diverse community input quickly patches bugs and introduces novel solutions, which inherently challenges the slow, centralized evolution typical of certified systems.
What assumptions are made about the viability of unregulated data streams versus regulated ones? Who benefits from keeping decoding methods proprietary or closed? How does the development of low-cost hardware through open design impact the concept of safety assurance when deployed in complex systems like drone autopilots?
What follow-up research would test the robustness of the community-validated filtering algorithms against real-world anomalies, and how might formal certification processes accommodate rapidly evolving, distributed hardware solutions?
Sentinel — Human
This text reads like an in-depth technical article written by an engaged developer or community leader who is simultaneously educating the public about a standard and promoting their open-source hardware project.