This is source code to read analog voltage using ESP-32 (Node32S) GPIO 36 or ADC 0.
IDE: VS Code
Extension: Platform IO
You can use source code in file main.cpp to Arduino IDE and INO file, just comment line //#include <Arduino.h>
In this source code is included calibration or correction factor to match output voltage that read by ESP32ADC to voltage value that showed at power supply voltage indicator.