Can anyone help me figure out how the circuit works?

Question

Electronics

Answer 1

turning on all the libastrals, calling on the vangu and other seers, I report:
in the leftmost rectangle - the equivalent of the input parameters (apparently voltage)
in the middle rectangle with an uncountable number of legs - a microcontroller that performs several functions, such as: analog-to-digital signal conversion, fluid control -crystal indicator
rectangle on the right - in fact, a liquid crystal indicator.

Answer 2

The principle is simple, one might say primitive-standard.
From the middle output of the potentiometer, the voltage is applied to the analog input MK RA0, where it is converted into a digital value, which is displayed on the LCD indicator. The LCD indicator is configured to work via a 4-bit interface.

Answer 3

What's the question?

Answer 4

I see an error in the circuit: the microcontroller was left without power.
Accordingly, the principle of the scheme is simple: do not work.