#include <Arduino.h>

const uint8_t ROWS = 3;
const uint8_t COLS = 3;

char keys[ROWS][COLS] = {
  { '1', '2', '3' },
  { '4', '5', '6' },
  { '7', '8', '9' }
};

uint8_t colPins[COLS] = { A3, A4, A5 };
uint8_t rowPins[ROWS] = { A0, A1, A2 };


void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);

  // Set column pins as outputs and row pins as inputs
  for (uint8_t col = 0; col < COLS; col++) {
    pinMode(colPins[col], OUTPUT);
    digitalWrite(colPins[col], HIGH);  // Set column pin high
  }
  for (uint8_t row = 0; row < ROWS; row++) {
    pinMode(rowPins[row], INPUT_PULLUP);  // Use internal pull-up resistors
  }
}

void loop() {
  // Scan the keypad matrix
  for (uint8_t col = 0; col < COLS; col++) {
    digitalWrite(colPins[col], LOW);  // Set current column low
    for (uint8_t row = 0; row < ROWS; row++) {
      if (digitalRead(rowPins[row]) == LOW) {
        // Key press detected
        char key = keys[row][col];
        Serial.println("Key pressed: " + String(key));

        // Wait until the key is released
        while (digitalRead(rowPins[row]) == LOW) {
          // Wait
        }
      }
    }
    digitalWrite(colPins[col], HIGH);  // Restore current column to high
  }
}