It’s GNU Radio Companion, But In The Browser

September 9, 2026 by Jenny List 15 Comments

The progression of the web browser from a tool for simple static information browsing into a do-everything computing environment has been inexorable, with package after package making the jump. Today it’s the turn of GNU Radio Companion, lowering the barrier to software defined radio considerably. It’s the work of [Marc Lichtman], who’s name you may recall if you have ever used pysdr.org.

Loading it up gives you a very familiar window if you’re used to GNU Radio Companion, and it comes with a set of example flowgraphs that cover a large range of applications. It supports a collection of software-defined radios (SDRs) including the well-known RTL-SDR, and if that’s not enough it can also use your sound card. There is even a set of recorded off-air captures to experiment with.

We’ve spent a while here playing with it, and it does everything we’re used to from the version outside the browser. The only thing we’re told it won’t do is work with a networked SDR, but that’s no deal breaker.

Thanks [Marcus Müller] for the tip.

GNU Radio Gets A Makeover With PimpMyGRC

March 14, 2026 by Zoe Skyforest 11 Comments

[idealdealy] had a problem. GNU Radio Companion was proving to be a powerful tool, but it just didn’t look… cool enough. The solution? A custom bit of software called PimpMyGRC, designed to jazz things up a bit in everyone’s favorite open-source SDR package.

In the creator’s own words, PimpMyGRC solves the problem nobody had with GNU Radio. It stemmed from [idealdealy]’s desire to have a plain black background in the software to ease eye strain during late night debug sessions. From there, it developed into a full theming package coded in Python, complete with all kinds of fun color schemes.

You can go with “arctic” if you’re somewhere cold, “bubblegum” if you’re feeling young and fun, or “neon hacker” if you’re still obsessed with early 90s movies with terrible plot holes around computers.

None of these themes will help you work faster, but they’ll probably make your friends jealous that your setup looks a little bit cooler than theirs. Plus, there are some really fun animated effects to catch your eye if your attention is fading. You might get flames dancing on the bottom of the screen, or binary digits falling through the display in a manner vaguely akin to terminals from The Matrix.

If you’re new to this world, you might like to check out this primer on getting started with GNU Radio. Meanwhile, if you’re cooking up your own SDR hacks of value, don’t hesitate to notify the tipsline!

Reverse Engineering A (Toy) Fire Engine

September 6, 2025 by Al Williams 3 Comments

Your kid has a toy remote control fire truck. You have an RTL SDR. See where this is going? [Jacob] couldn’t resist tearing into the why and how of the truck’s remote control protocol.

The entire process began with a basic GNU Radio setup to determine the exact frequency of the signal. Then a little analysis suggested that it might be using amplitude shift keying. That is, the information is in the amplitude of the signal, where one possible amplitude is completely off in some cases.

Continue reading “Reverse Engineering A (Toy) Fire Engine” →

Roll Your Own SSB Receiver

August 19, 2025 by Al Williams 3 Comments

[Paul Maine] was experimenting with GNU Radio and an RTL-SDR dongle. He created an SSB receiver and, lucky for us, he documented it all in a video you can see below. He walks through how to generate SSB, too. If videos aren’t your thing, you can go back to the blog post from [Gary Schafer] that inspired him to make the video, which is also a wealth of information.

There is a little math — you almost can’t avoid it when talking about this topic. But [Paul] does a good job of explaining it all as painlessly as possible. The intuitive part is simple: An AM signal has most of its power in the carrier and half of what’s left in a redundant sideband. So if you can strip all those parts out and amplify just one sideband, you get better performance.

Continue reading “Roll Your Own SSB Receiver” →

Decoding Meshtastic With GNU Radio

June 26, 2024 by Al Williams 22 Comments

Meshtastic is a way to build mesh networks using LoRa that is independent of cell towers, hot spots or traditional repeaters. It stands to reason that with an SDR and GNU Radio, you could send and receive Meshtastic messages. That’s exactly what [Josh Conway] built, and you can see a video about the project, Meshtastic_SDR, below. The video is from [cemaxecuter], who puts the library through its paces.

For hardware, the video uses a Canary I as well as the WarDragon software-defined radio kit which is an Airspy R2 and a mini PC running Dragon OS — a Linux distribution aimed at SDR work — in a rugged case. GNU Radio, of course, uses flows which are really just Python modules strung together with a GUI.

Continue reading “Decoding Meshtastic With GNU Radio” →

Roll Your Own SDR

December 16, 2023 by Al Williams 8 Comments

If you have software-defined radio hardware and you are only using someone elses’ software, you are missing out on half of the fun. [Tech Minds] shows you how easy it can be to roll your own software using GNU Radio Companion in a recent video.

GNU Radio usually uses Python, but with the companion software you rarely need to know any actual Python. Instead, you simply drag blocks around to represent filters, DSP processing, and other functions you need to create the processing for your application.

Continue reading “Roll Your Own SDR” →

Listening To A Flashlight — Lunar Flashlight

January 23, 2023 by Al Williams 4 Comments

If you’ve been looking for a practical example of using GNU Radio, you should check out [Daniel Estévez’s] work on decoding telemetry captured from the Lunar Flashlight cubesat. The cubesat is having some trouble, but the data in question was a recording from the day after launch. We aren’t sure what it would take to eavesdrop on it live, but the 3-minute recording is from a 20-meter antenna at 8.4 GHz.

The flowgraph for GNU Radio isn’t as bad as you might think, thanks to some judicious reuse of blocks from other projects to do some of the decoding. The modulation is PCM/PM/bi-phase-L. Nominally, the speed is supposed to be 48,000 baud, but [Daniel] measured 48,077.

Continue reading “Listening To A Flashlight — Lunar Flashlight” →