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- Hacker News
- Cool. On github forked and starred. Thank you.by gvieri
- Please don't use "fork" as a bookmark, it's quite annoying.by ghostly_s
- This is so cool! Congrats!by miki_tyler
- They put radio on the Internet... ¡Tres Comas!by codingjoe
- That's certainly handy... here's a simple audio frequency shifter I threw together[1].
First it takes the audio from your microphone. It then feeds it through a Hilbert transform to convert incoming audio into an IQ (complex) format. The advantage of an IQ signal format is that when you multiply it by another signal, the frequencies add or subtract, without getting extra image frequencies. This is why it's worth doing twice the computation in DSP work.
Then your audio is multiplied by a cosine wave with a frequency determined by a GUI slider, from -2000 to 2000 Hz.
This has the net effect of raising or lowering the pitch of your voice, like tuning in a single sideband transmission on ham radio.
To get the results out to the speakers, it samples only the real component to send to the audio output.
The net effect is it can raise or lower the frequency of your voice.
[1] https://gnuradioworld.com/#fg=H4sIAAAAAAAACsVXS2_bOBC--1fMTR...
by mikewarot - Hey this is Marc, I just posted your example flowgraph to the site, after adding some Time Sinks to visualize the sound. Should be under the Audio category of example flowgraphs. Really glad you played around with it!!by pysdr
- That’s amazing, thanks for the share! I did a small test, it works, screen is a bit harder to navigate on small screens but not an issue.by tamimio
- Good to know, I'll see what I can do! There are zoom buttons for the editor but I imagine it's more about the left pane.by pysdr
- This is super cool! It reminds me of MaxMSP and really takes me back to some signal processing classes. The GUI is pretty nice to interact with. I'll definitely be playing around with this some more, awesome project!by baileynoack
- Thanks!!!by pysdr
- I'm glad people like it!!! I'll keep working on improving the site and adding support for more SDRs and OOTs. My initial motivation for creating GNU Radio World was to have a way to embed interactive examples into PySDR.org, which I have started to do, eg see https://pysdr.org/content/sync#frame-synchronization. I think GNU Radio World has a lot of potential directions it could go, and if anyone is interested in helping out with it feel free to join the Discord server or email me.
-Marc
by pysdr - I tinkered with gnuradio back when rtl-sdr just took off (2012ish?).
I had no background in dsp or signal processing and found it so opaque as to be unusuable, even though I saw more skilled folks do amazing things with it.
*scratches head*
Might give it another go.
by jcims - At the end of the day, DSP is a lot of math and a lot of hardware. A lot of GNU Radio's code is a monster unification of so many different choices into certain interfaces (or duplication of the same choices) for, presumably performance reasons? Or just keeping every single DSP technique ever in the God Library for the super power greybeard to use.
If you have a certain DSP goal in mind (say, RF comms), and you want to do stuff but not absolutely balls-to-the-walls processing (at that point, presumably you'd move to hardware), you can design your stack in fairly modular and composable ways. The field is pretty mature and the techniques just work.
In a software context, you can decompose the abstractions fairly cleanly. You won't get 5G high performance networking but you can get good enough results.
by sigbottle - I have to say having just done a very tricky project with a long DSP pipeline in gnuradio, that LLMs are a godsend for getting up to speed on gnuradio blocks. I too found it historically impenetrable, but was able to get a pipeline completed. That said, prepare yourself for a lot of debugging and work to diagnose problems if you’re doing anything of sufficient complexity.by Enginerrrd
- Run through pysdr[0], which I found has the right complexity gradient and the right levels of abstraction for people with technical chops but who aren’t familiar with SDRby stackghost
- I've tinkered with SDR some and did a bit professionally. I always found GNU Radio to fall into the uncanny valley - too GUI to scratch my programming itch but too low-level to be useful for exploration. Between libraries like `pyrtlsdr` and desktop apps like `sdrangel`, I can't seem to find a niche for GNU Radio.by perrygeo
- New textbook may helpby vmilner
- No idea what I'm looking at, it's just combining some noise and a sawtooth wave to create pretty visuals I guess? if this is meant to serve as an introduction to the project it's not really succeeding. The "Description" isn't even readable despite most of the page being used for empty space. I guess it's expected to have no audio output? I presume the real purpose of this is to process signals from an actual radio?
The "Help"->"Help" menu item is notably unhelpful:
> For questions, comments, or suggestions, you can email support@gnuradioworld.com, join the Discord server, or post a GitHub issue.
"Help"->"About" at least starts to clarify some things:
> GNU Radio, entirely in your browser — explore the open-source SDR ecosystem with zero install!
> GNU Radio World is a browser-based GNU Radio Companion flowgraph editor and WebAssembly runtime. You can place, connect, and configure blocks, then run the resulting flowgraph directly in your browser.
> It is designed to download only the WebAssembly modules corresponding to the blocks you use. This on-demand architecture keeps the initial download small and can support a limitless collection of out-of-tree modules (OOTs) in the future.
> GNU Radio World also includes a collection of real RF recordings that are downloaded only when you use them. You can inspect the recordings in the built-in recording view, adapted from IQEngine, and use them in the included flowgraph examples, allowing OOTs to be shown off with real recordings of the corresponding signals
by ghostly_s - Hey it's Marc, creator of GNU Radio World, I'm glad you brought this up, I made it thinking it would be used by folks already familiar with GNU Radio, but this site can double as a way to introduce new people to GNU Radio, so it might as well have a more friendly introduction that walks you through the basics. I'll start working on it!by pysdr
- Oh that's cool!
I've set off time to blog about getting my broadband RF scanner (connecting to USRP B200 via WebUSB) to work in WASM.
It's basically https://blog.habets.se/2026/08/Broadband-RF-scanner-revisite..., but in the browser.
I also have an AX.25 decoder (https://thomashabets.github.io/ruwasm/) and plain old FM receiver (https://cement.retrofitta.se/tmp/rtlsdr-fm/) already. The latter two work with RTL-SDR, also via WebUSB, so no software installs or setup required.
I've been meaning to make a "GNU Radio in the Browser" (well, gnuradio-companion-like) for my RustRadio project to build flowgraphs without coding, but not gotten to it yet.
- Off-topic:
retrofitta
Definition
Add (a component or accessory) to something that did not have it when manufactured.
What did you think it meant?
[EoF]
Strålande! Well done :)
"Fitta" is sort of like "cunt" in Swedish & .se is the TLD of Sweden.
by kruffalon - With wasm, I see a future where the browser and thus web technologies are a UI toolkit for a Linux desktop environment. It already is, people hardly use GTK and qt anymore except for desktop environments or embedded like on cars due to performance limitations. It would be cursed to see a browser running within a browser. But then replacing a desktop environment might be the limit of replacing GTK qt and other UI toolkits with web technologies, making it unnecessary and opposite to the reason people use Linux which is performanceby alightsoul