Basic Arduino LCD and Keypad Example Code

This code is about basic example where we interface a 4×4 keypad with Arduino and one 20×4 LCD with Arduino. You can also use 16×2 LCD with Arduino in same code. Here is the complete working code example.

#include <LiquidCrystal.h>
#include <Keypad.h>

const int rs = 7, en = 6, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {8, 9, 10, 11}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {A0, A1, A2, A3}; //connect to the column pinouts of the keypad

Keypad keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup(){
  lcd.begin(20, 4); // initialize the LCD with 20x4 characters
  lcd.setCursor(0, 0);
  lcd.print("Press a key:");
}

void loop(){
  char key = keypad.getKey();
  if (key){
    lcd.setCursor(0, 1);
    lcd.print("Pressed: ");
    lcd.print(key);
  }
}
Code language: Arduino (arduino)