diagram.json

#include <Arduino.h>
#include "input.h"

void setup() {
  Serial.begin(9600);
  inputSetup(); // Initialize the button matrix
}

void loop() {
  int button = readButton(); // Check which button is pressed
  if (button != -1) {
    Serial.print("Button pressed at row: ");
    Serial.print(button / COLS);
    Serial.print(", col: ");
    Serial.println(button % COLS);
  }
  delay(100); // Short delay for debounce
}


main.cpp

#ifndef INPUT_H
#define INPUT_H

#include <Arduino.h>

#define ROWS 5
#define COLS 6

extern const int ROW_PINS[ROWS];
extern const int COL_PINS[COLS];

void inputSetup();
int readButton();

#endif


input.h

#include "input.h"
#include <Arduino.h>

const int ROW_PINS[ROWS] = {3, 0, 1, 10, 19};
const int COL_PINS[COLS] = {18, 4, 5, 6, 7, 2};

void inputSetup() {
  for (int i = 0; i < ROWS; i++) {
    pinMode(ROW_PINS[i], OUTPUT);
    digitalWrite(ROW_PINS[i], HIGH);
  }
  for (int j = 0; j < COLS; j++) {
    pinMode(COL_PINS[j], INPUT_PULLUP);
  }
}

int readButton() {
  for (int row = 0; row < ROWS; row++) {
    digitalWrite(ROW_PINS[row], LOW);
    for (int col = 0; col < COLS; col++) {
      if (digitalRead(COL_PINS[col]) == LOW) {
        while (digitalRead(COL_PINS[col]) == LOW); // Wait for button release (simple debounce)
        return row * COLS + col; // Return unique number for each button
      }
    }
    digitalWrite(ROW_PINS[row], HIGH);
  }
  return -1; // Return -1 if no button is pressed
}
