WebAssembly build of GNU Radio


Experimental WebAssembly build of GNU Radio that runs in a browser tab


For some reason I thought it would be easy

narrator: it was not, in fact, easy

but I eventually got a proof-of-concept ~working, so I thought I’d share ?

status: experimental proof-of-concept

This is a proof-of-concept WebAssembly build of GNU Radio Companion which can generate and run basic flowgraphs. It includes gr-qtgui and supports visualization using the QT GUI sink-blocks.

The GNU Radio Companion UI is running the feature-grc-qt branch of GNU Radio, which itself is a work-in-progress, so some basic capabilities (like the ability to edit block properties) are missing.

Support for USB software-defined radios is not yet implemented, but will be possible. (Earlier in the pandemic I published standalone WebUSB proof-of-concepts for USRP B210, HackRF, and PlutoSDR.)

how to run a simple flowgraph with QT GUI visualization

  1. run cd webapp && ./server.py

  2. open your web browser (and the F12 developer-tools)

  3. navigate to http://localhost:8000

    It will block on the browser UI thread while loading, which takes on the order of 15-30 seconds. If you have the developer console open, you can watch stdout/stderr while it loads.

  4. add/connect some blocks (eg. Signal Source -> Throttle -> QT GUI Sink)

  5. click Generate

  6. click Execute

how make gnuradio-web

The repo includes prebuilt binaries, but if you like watching cross-compilation marathons, you can build it from source:

  1. install docker, docker-compose, and emsdk

  2. run make base && make webapp in the repository root

    (I’ve only tested this on an Ubuntu 20.04 x86_64 host. It probably works in other environments but YMMV.)

simple flowgraph demo



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