Following my success with integrating the frequency control widget from cutesdr into gqrx I have decided to try the same with the FFT plot and waterfall widget. This too seemed to be a single C++ class that might be easy to integrate into my experimental software receiver powered by GNU Radio and Qt GUI.
The Universal Hardware Driver (UHD) for the USRP contains a cool example program that can draw spectrum scope using simple ASCII art. This video shows reception of 8 MHz wide spectrum slices in the broadcast FM band 88 – 108 MHz.
Demonstration of a the persistence function of the FFT plot in GNU Radio. Persistence emulates the look of very old CRT monitors where the cursor leaves a trace of shadow. This is a new eye candy in the GNU Radio and will be available in version 3.3.0