Finding back the data

GNU Radio is a set of software tools that allows you to create a signal processing chain for the data that comes from your SDR hardware (or a file) to either your hardware again (to emit) or a file. The blocks in its GUI (gnuradio-companion) are individual processing steps in the signal processing chain. Data comes from a source toward a sink (both are files or your SDR hardware driver, your sound card, or... well, it can be a lot of things: another program, a network endpoint, and so on).

NOTE

gnuradio-companion (grc) has two main GUI frameworks it can talk to: QT and WX. Depending on your installation, you may have to change the framework in the generate options block. The GUI-related processing blocks will also have to be changed in the processing flow itself.

So, let's fire up gnuradio-companion and make a receiver.

First, let's replicate Gqrx and let's have an FFT visualization. FFT is a visualization of the signal in the frequency domain...