Check the "Reference Voltage" in your code. Proteus defaults to 5V; if your MCU is set to 3.3V, your math will be off.
Using 30k and 7.5k resistors, a 25V input becomes exactly 5V, making it perfectly safe for an Arduino analog pin. Step-by-Step Simulation Guide
Most hobbyists use the or the "New Sensors Library for Proteus" created by third-party developers like The Engineering Projects. Steps to Install: voltage sensor proteus library
Paste these files into the Proteus installation directory.
Reducing high input voltage to a safe analog range. Check the "Reference Voltage" in your code
Connect the TX/RX pins to a Virtual Terminal so you can see the calculated voltage values on your screen.
Use the following logic in your Arduino IDE: Step-by-Step Simulation Guide Most hobbyists use the or
Close and reopen Proteus to refresh the component list. Simulating a Voltage Sensor Without a Custom Library