Month: November 2013

Piping IQ data from rtl_sdr to wav file


  1. A program called pipeiq.c
  2. A streaming method called borip

It could solve the issue of getting IQ samples into Max – until I can write a Max external which reads the device directly.

I have saved the pipeiq.c local file to: tkzic/radio-sdr-experiments

Here are links to information about borIP – a program that streams radio IQ data over UDP to a simulated USB port – at least i think thats what it does.

There are also instructions here for installing GR (gnu radio) on mac os

Piping raw IQ data from rtl-sdr to Max


Here is a discussion about mkfifo (pipes) but  I can’t seem to get Max to interpret the FIFO as audio samples

I think I know how to figure out the streaming IQ thing now. Capture samples to a file, then look at the format. Then maybe pipe the file through something like auconvert to make it into a wave file. If that works, then maybe there is a way to to it as streaming.

Or figure out how to stream from tcp/ip version to audio.

rtl-sdr commands for testing

Had to install play (from sox) in /usr/bin

Gqrx came with the rtl command set – you can run the commands from


This command tunes to FM broadcast and plays

./rtl_fm -f 90100000 -W -s 200000 -r 48000 - | play -r48000 -t s16 -L -c 1 -