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

// Keypad configuration
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] = {9, 8, 7, 6}; // connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // connect to the column pinouts of the keypad

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

// LCD configuration
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

char input = '\0'; // to store the input from the keypad

void setup() {
  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.print("Select Relay:");
  lcd.setCursor(0, 1); // move the cursor to the second row
  
  // Initialize relay pins
  pinMode(A1, OUTPUT);
  pinMode(A2, OUTPUT);
  pinMode(A3, OUTPUT);
  
  // Ensure all relays are off initially
  digitalWrite(A1, LOW);
  digitalWrite(A2, LOW);
  digitalWrite(A3, LOW);
}

void loop() {
  char key = keypad.getKey();
  
  if (key) {
    if (key == '#') {
      // Enter key pressed
      lcd.clear();
      lcd.print("Selected:");
      lcd.setCursor(0, 1);
      lcd.print(input);
      controlRelay(input);
      delay(2000); // wait for 2 seconds
      lcd.clear();
      lcd.print("Select Relay:");
      lcd.setCursor(0, 1);
      input = '\0'; // clear the input after displaying
    } 
    else if (key == '*') {
      // Backspace key pressed
      if (input != '\0') {
        input = '\0'; // clear the input
        lcd.clear();
        lcd.print("Select Relay:");
        lcd.setCursor(0, 1);
      }
    } 
    else if (key == 'A' || key == 'B' || key == 'C') {
      // Option key pressed
      input = key;
      lcd.setCursor(0, 1);
      lcd.print(input);
    }
  }
}

void controlRelay(char selection) {
  // Turn off all relays initially
  digitalWrite(A1, LOW);
  digitalWrite(A2, LOW);
  digitalWrite(A3, LOW);

  // Turn on the selected relay
  switch (selection) {
    case 'A':
      digitalWrite(A1, HIGH);
      break;
    case 'B':
      digitalWrite(A2, HIGH);
      break;
    case 'C':
      digitalWrite(A3, HIGH);
      break;
    default:
      // Do nothing if the selection is invalid
      break;
  }
}