Building SDR apps by mapping IQ streams with pipes in CLI or bash scripts.

• Taking IQ stream from SoapySDR, Airspy HF+ and Sound card input
• Generating IQ stream with noise or empty signal
• Transmitting internet audio streams into IQ stream
• Lowpass filtering and decimating IQ stream
• Piping streams to TCP, GQRX, Icecast, playing it as an audio
• Generating waterfall image from IQ stream
• Playing and streaming waterfall as video
• SSB demodulation

sudo apt install ffmpeg icecast2 sox

When Icecast asks to configure it say no, because we will use the config we have in the project.

Install it from https://github.com/pothosware/SoapySDR/

If you want to get IQ stream from Airspy install their software from https://github.com/airspy

You can take IQ stream from sound card stereo input, just make sure arecord command is working in your command line.

Open the project root folder and run ./build

If you want to use Icecast, go to the icecast folder and run ./start-icecast, the port is 4625. If you want to share the Icecast stream via Internet - don't forget to replace the hackme password with some stronger.

Look into bash scripts in the project root and connect modules with pipes similarly for your app. Use scripts in tune/ folder to set common parameters like samplerate, antenna, default frequency, remote server IP.

Some apps can run on Raspberry Pi Zero. Other will require more calculation performance. Notice that Raspberry Pi Zero CPU bcm2835 can easily work at 1GHz so don't hesitate to overclock it.

• KissFFT - https://github.com/mborgerding/kissfft
• TFilter - http://t-filter.engineerjs.com/