//https://forum.arduino.cc/t/midi-controller-4-pots-on-one-lcd/1190027

#include <LiquidCrystal_I2C.h>     // if you don´t have I2C version of the display, use LiquidCrystal.h library instead

LiquidCrystal_I2C lcd(0x27, 16, 2); // set the LCD address to 0x27 for a 16 chars and 2 line display

// define your input data
struct Input {
  const uint8_t pin;       // the ADC pin you want to measure
  uint16_t previousValue;  // store the old value
};

// define your inputs
Input input[] {
  {A0, 0},
  {A1, 0},
  {A2, 0},
  {A3, 0},
};

constexpr uint8_t threashold = 1;

void setup() {
  lcd.init();                       // initialize the 16x2 lcd module
  lcd.backlight();                  // enable backlight for the LCD module
  lcd.println(F("Measure ADC"));
  delay(500); // show startup message
}

void loop() {
  for (auto &i : input) {
    // Input
    int currentValue = analogRead(i.pin);  // int is acceptable as we await 0..1023 only 
    // Process
    int difference = currentValue - i.previousValue;
    difference = abs(difference);
    // Output
    if (difference >= threashold) {   // only print when new value has changed enough
      lcd.setCursor(0, 0);
      lcd.print(F("ADC pin"));
      lcd.print(i.pin);
      lcd.print('=');
      lcd.print(currentValue);
      lcd.print(F("    ")); // delete "old" remaining characters
      i.previousValue = currentValue;
    }
  }
}