Custom UI Question

Hello, first of all thanks to everyone in this forum for your support. Secondly, sorry for my english, I’m from Madrid, Spain. I’m a graphic designer finishing my degree, and my final project is a visual interface for a simple synth. I’m using “preseted” knobs but i would like to implement one custom ui element. I would like to have this kind of element (see image):
Captura de pantalla 2019-05-06 a las 17.19.38.png

What i’m trying to do is a knob that changes the wave form, everything works till here, but i don’t know how i can make that left widget, where when i change the value in the knob, it also changes the text in the blue rectangle, and the “led light” in the upper graphic.

If anyone could help me i’ll be very glad, i have to finish my proyect by the end of the month and if this is very difficult to do i’ll need to change all my interface to work only with knobs (as a graphic designer the jury will find much more pleasant the ui element i showed you)

Thank You Very Much

Harry-