LuaRadio is a lightweight, embeddable flow graph signal processing framework for software-defined radio. It provides a suite of source, sink, and processing blocks, with a simple API for defining flow graphs, running flow graphs, creating blocks, and creating data types. LuaRadio is built on LuaJIT, has a small binary footprint of under 750 KB (including LuaJIT), has no external hard dependencies, and is MIT licensed.

LuaRadio can be used to rapidly prototype software radios, modulation/demodulation utilities, and signal processing experiments. It can also be embedded into existing radio applications to serve as a user scriptable engine for processing samples.

LuaRadio blocks are written in pure Lua, but can use LuaJIT's FFI to wrap external libraries, like VOLK, liquid-dsp, and others, for computational acceleration, more sophisticated processing, and interfacing with SDR hardware.

Use GNU Radio? See how LuaRadio compares to GNU Radio.

local radio = require('radio')

radio.CompositeBlock():connect(
    radio.RtlSdrSource(88.5e6 - 250e3, 1102500), -- RTL-SDR source, offset-tuned to 88.5MHz-250kHz
    radio.TunerBlock(-250e3, 200e3, 5),          -- Translate -250 kHz, filter 200 kHz, decimate by 5
    radio.FrequencyDiscriminatorBlock(1.25),     -- Frequency demodulate with 1.25 modulation index
    radio.LowpassFilterBlock(128, 15e3),         -- Low-pass filter 15 kHz for L+R audio
    radio.FMDeemphasisFilterBlock(75e-6),        -- FM de-emphasis filter with 75 uS time constant
    radio.DownsamplerBlock(5),                   -- Downsample by 5
    radio.PulseAudioSink(1)                      -- Play to system audio with PulseAudio
):run()

Check out some more examples of what you can build with LuaRadio.

With LuaJIT installed, LuaRadio can be run directly from the repository:

git clone https://github.com/vsergeev/luaradio.git

$ cd luaradio
$ ./luaradio --platform
luajit          LuaJIT 2.0.4
os              Linux
arch            x64
page size       4096
cpu count       4
cpu model       Intel(R) Core(TM) i5-4570T CPU @ 2.90GHz
features
    fftw3f      true
    volk        true
    liquid      true
$

LuaRadio is accelerated by the optional libraries liquid-dsp, VOLK, and fftw for real-time applications. To run the real-time examples, install liquid-dsp or VOLK, and check that liquid or volk are marked true in the platform information.

LuaRadio primarily supports Linux. It also strives to support FreeBSD and Mac OS X, but real-time support and audio sink support on these platforms is currently experimental.

Try out one of the examples with an RTL-SDR dongle:

$ ./luaradio examples/rtlsdr_wbfm_mono.lua 91.1e6

LuaRadio and all of its examples run great on the Raspberry Pi 3 with Arch Linux.

See the Getting Started guide for a tutorial on building your own flow graphs.

Arch Linux users can install LuaRadio with the AUR package luaradio.

See the Installation guide for other installation methods.

LuaRadio documentation is contained in the docs folder.

• 0. Reference Manual
• 1. Installation
• 2. Getting Started
• 3. Creating Blocks
• 4. Embedding LuaRadio
• 5. Architecture
• 6. Comparison to GNU Radio

• radio/ - Radio package
  • core/ - Core framework
  • types/ - Basic types
  • blocks/ - Blocks
    • sources/ - Sources
    • sinks/ - Sinks
    • signal/ - Signal blocks
    • protocol/ - Protocol blocks
  • composites/ - Composite blocks
  • thirdparty/ - Included third-party libraries
  • init.lua - Package init
• examples/ - Examples
• embed/ - Embeddable C library
  • Makefile - C library Makefile
  • luaradio.c - C API implementation
  • luaradio.h - C API header
  • examples/ - C API examples
  • tests/ - C API unit tests
• benchmarks/ - Benchmark suites
  • luaradio_benchmark.lua - LuaRadio benchmark suite
  • gnuradio_benchmark.py - GNU Radio benchmark suite
• docs/ - Documentation
  • refman/ - Reference manual generator
• tests/ - Unit tests
  • generate/ - Unit test code generators (Python 3)
• ChangeLog.md - Change Log
• README.md - This README
• LICENSE - MIT License
• luaradio - luaradio runner helper script executable

LuaRadio unit tests are run with busted:

busted --lua=luajit --lpath="./?/init.lua" --no-auto-insulate tests/

LuaRadio is MIT licensed. See the included LICENSE file.