Connect the TX/RX pins to a Virtual Terminal so you can see the calculated voltage values on your screen.
In the real world, an Arduino or PIC microcontroller cannot directly read high voltages (e.g., 12V or 24V) because their GPIO pins are rated for 5V or 3.3V. In Proteus, you need a sensor model that mimics this behavior: voltage sensor proteus library
If you see "No Simulator Model," ensure you have correctly placed the .LIB files in the DATA\LIBRARY folder, not just the root folder. Connect the TX/RX pins to a Virtual Terminal
Simulating the linear relationship between input and output. voltage sensor proteus library
Most hobbyists use the or the "New Sensors Library for Proteus" created by third-party developers like The Engineering Projects. Steps to Install: