You can see it in a youtube video at: https://youtu.be/53N_Wv3248g If you do not like the rotation sense of your digital encoder and want to change it, just switch among them the wires going into D2 and D3 Libraries: #include <LiquidCrystal_I2C.h> // fmalpartida library, from https://github.com/fmalpartida/New-LiquidCrystal , updated November 24th 2020 // if you have already a library LiquidCrystal_I2C in your library folder you need to delete it (or move it), otherwise will interfere with the useful library #include <si5351.h> // Adafruit Si5351 library, version 1.2.0 The Si5351 signal generator board has 3 clocks. I use only CLK0 and CLK2. - CLK 0 generates a variable frequency, between 4 KHz and 225 MHz (the board is version A, Si5351A). Safer would be to limit between 8 KHz and 160 MHz, but it works in a wider range. - CLK 2 generates a fixed frequency, which I called in the program IntermediateF, and has a fixed value of 10.7 MHz, which can be changed in the program.