Our firmware is fully open source, and our UAT decoder was introduced last year and has been working well (I think we've shaken all the bugs out at this point). We implemented everything from scratch so that it would run efficiently on our embedded RF MCU (TI CC1314). We support both UAT ADSB and UAT uplink (weather / traffic data).

Our firwmare repo is here: https://github.com/PantsForBirds/adsbee. It's always open for bug reports or PRs!

ADSBee 1421's very low power consumption is determined by its architecture. Where ADSBee 1090 has a discrete RF frontend with multiple power hungry LNAs and a power detector chip, plus a dual core RP2040, an ESP32 S3 module, and a CC1312, ADSBee 1421 just has an LR2021 chip and a CC1314. A single LNA on the ADSBee 1090's RF frontend actually draws about as much power as the whole m1421!

The tradeoff is that we have fewer CPU cycles available for crunching packets compared to the ADSBee 1090, and the LR2021 has some quirks that result in it only being able to receive ADS-B packets in its maximum dynamic range configuration (so we support Mode S DF17 only, no squitter packets or altitude / surveillance replies like you get with DF4/5/11). That said, this has been plenty for customers who are looking for an aircraft detect and avoid solution plus UAT traffic / weather.

Based on our testing so far, ADSBee m1421 is well suited to general aviation applications (portable flight bag / cockpit avionics), drone flight controllers (aircraft detect and avoid), and anything that needs to be low cost or easy to run off a solar panel or little battery.

For customers looking to build something like an airport ground station, where they want all squitter and extended squitter packet formats and a higher max packet rate, we still recommend the ADSBee 1090 three-MCU architecture.

We're focusing on embedded applications with ADSBee m1421 applications right now but it's definitely tempting to roll m1421 into a smaller flight bag device. It's something we might get back around to once we have Winglet off the ground.

Comments URL: https://news.ycombinator.com/item?id=49455557

Points: 38

# Comments: 8

I spent a bunch of time getting the timestamps on the custom receiver to be sub-microsecond accurate (https://pantsforbirds.com/adsbee-1090-july-2025-update/), so the receiver is capable of feeding multilateration (MLAT) networks which decode position based on time of flight of received packets. Combining that feature with live GPS updates would allow creation of an MLAT network with moveable base stations, which would be pretty cool.

ADSBees can be fully configured over their network connection, including flashing new firmware, so if you put them onto some sort of VLAN network you could update and configure each device pretty easily. They use a network console accessible via USB or WebSocket for configuration and firmware updates.

I'd love to hear what people think about the project, or answer any questions. I've been posting regular updates to the blog on my website, it's been a very fun journey taking an open source hardware project from an idea to a business that makes and ships real things: https://pantsforbirds.com/blog/

Comments URL: https://news.ycombinator.com/item?id=46459195

Points: 8

# Comments: 3

I consulted it a lot while working on an open-source ADS-B receiver project that decodes Mode S using RP2040 PIO. https://github.com/CoolNamesAllTaken/adsbee/