KiwiSDR Three knob Webtuner This software was at first initiated by PA1KE 7 may 2021 badsed on an article in the Dutch Ham magazine "Electron" April 2021 where an indication of use of one (optical) Rotary encoder for Web SDR control was suggested for a limited set of functions for several WebSDR's.
The first ALFA release of this software was done on Github at 26 mai2021
The idea of the Three Knob (Kiwi)SDRTuner is to access
all the functions that are made accessible by keystrokes in the original
KiwiSDR software. This is done by means of a small XIAO (SAMD21), Arduino like)
processor board. Besides the XIAO only three ordinary (cheap) rotary encoders with an OLED dsplay 128x64
are the only components used.
The software generates keyboard codes and sends them via the USB (C) port of the XIAO to the device that runs the websdr software in a browser thus emulating a real keyboard connection. The keys are sent to the device regardless the software it runs, so the TKKT (Three Knob KIWI Tuner) starts in a locked mode where actually nothing is sent to the device running the browser with the SDR running in it. (This to prevent unwanted keystrokes into to whatever software runs at the moment the TKKT is connected to the USB port).
Opposite to optical encoders these ordinary rotary encoders need to be debounced. There is a very elegant solution to do this in software at: https://www.best-microcontroller-projects.com/rotary-encoder.html I used this software and it works quite well so no need for the rather encombrent optical ones.