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.
FFT
ASCII art FFT with USRP and UHD
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.
GNU Radio FFT Scope Persistence Demo
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