/**
   Mini piano for Arduino.

   You can control the colorful buttons with your keyboard:
   After starting the simulation, click anywhere in the diagram to focus it.
   Then press any key between 1 and 8 to play the piano (1 is the lowest note,
   8 is the highest).

   Copyright (C) 2021, Uri Shaked. Released under the MIT License.
*/
/* 这段程序是一个基于 Arduino 的音乐播放器。
它通过按下按钮来选择音调，并通过蜂鸣器播放指定的乐曲《大海》。
*/
#include "pitches.h"  // 引入共享的音调定义文件

#define SPEAKER_PIN 8  // 定义蜂鸣器连接的引脚
#define SWITCH_PIN 3   // 定义开关连接的引脚

const uint8_t buttonPins[] = { 12, 11, 10, 9, 7, 6, 5, 4 };  // 定义琴键连接的引脚数组
const int buttonTones[] = {
  NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4, NOTE_G5, NOTE_A5, NOTE_B4, NOTE_C5
  };  // 定义琴键对应的音调数组

  const int numTones = sizeof(buttonPins) / sizeof(buttonPins[0]);  // 计算琴键数量

  // 定义乐曲《大海》的音符名称数组
  const char* notes[] = {
    "C4", "E4", "G4", "E4", "C4", "E4", "G4", "E4",
      "C4", "E4", "G4", "F4", "E4", "F4", "G4",
        "C5", "A4", "G4", "F4", "E4", "D4", "E4", "F4", "G4", "A4",
          "C5", "A4", "G4", "F4", "E4", "D4", "E4", "F4", "G4", "A4",
            "G4", "E4", "C4", "D4", "E4", "F4", "G4",
              "G4", "E4", "C4", "D4", "E4", "F4", "G4"
              };

              // 定义乐曲《大海》的音调数组
              const int tones[] = {
                262, 330, 392, 330, 262, 330, 392, 330,
                  262, 330, 392, 349, 330, 349, 392,
                    523, 440, 392, 349, 330, 294, 330, 349, 392, 440,
                      523, 440, 392, 349, 330, 294, 330, 349, 392, 440,
                        392, 330, 262, 294, 330, 349, 392,
                          392, 330, 262, 294, 330, 349, 392
                          };

                          // 定义乐曲《大海》的每个音符的时长数组（以毫秒为单位）
                          const int durations[] = {
                            300, 300, 300, 300, 300, 300, 300, 300,
                              300, 300, 300, 300, 300, 300, 600,
                                300, 300, 300, 300, 300, 300, 300, 300, 300, 600,
                                  300, 300, 300, 300, 300, 300, 300, 300, 300, 600,
                                    300, 300, 300, 300, 300, 300, 600,
                                      300, 300, 300, 300, 300, 300, 600
                                      };

                                      bool musicPlaying = true;  // 音乐播放状态

                                      void setup() {
                                        for (uint8_t i = 0; i < numTones; i++) {
                                            pinMode(buttonPins[i], INPUT_PULLUP);  // 将琴键引脚设置为输入模式，使用内部上拉电阻
                                              }

                                                pinMode(SPEAKER_PIN, OUTPUT);  // 将蜂鸣器引脚设置为输出模式
                                                  pinMode(SWITCH_PIN, INPUT_PULLUP);   // 将开关引脚设置为输入模式，使用内部上拉电阻
                                                  }

                                                  void loop() {
                                                    int pitch = 0;

                                                      // 检测开关按钮是否按下，控制音乐的播放与停止
                                                        if (digitalRead(SWITCH_PIN) == LOW) {
                                                            musicPlaying = !musicPlaying;  // 切换音乐播放状态
                                                                delay(200);  // 延迟一段时间防止按键抖动
                                                                  }

                                                                    if (musicPlaying) {
                                                                        for (uint8_t i = 0; i < numTones; i++) {
                                                                              if (digitalRead(buttonPins[i]) == LOW) {  // 检测是否有琴键按钮按下
                                                                                      pitch = buttonTones[i];  // 获取对应的音调值
                                                                                            }
                                                                                                }

                                                                           if (pitch) {
                                                                                    tone(SPEAKER_PIN, pitch);  // 播放所选音调
                                                                                        } else {
                                                                                              noTone(SPEAKER_PIN);  // 停止播放音调
                                                                                                  }

                                                                                                      // 播放乐曲《大海》
                                                                                                          for (int i = 0; i < sizeof(notes) / sizeof(notes[0]); i++) {
                                                                                                                tone(SPEAKER_PIN, tones[i], durations[i]);  // 播放当前音符及其时长
                                                                                                                      delay(durations[i] + 50);  // 延迟一段时间后播放下一个音符
                                                                                                                          }
                                                                                                                            } else {
                                                                                                                                noTone(SPEAKER_PIN);  // 停止播放音调
                                                                                                                                  }
                                                                                                                                  }