#include "pitches.h"

#define SPEAKER_PIN 8
float sensorvalue;
const uint8_t buttonPins[] = { 12, 11, 10, 9, 7, 6, 5, 4 };
const int buttonTonesC[] = {
  NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4,
  NOTE_G4, NOTE_A4, NOTE_B4, NOTE_C5
};
const int buttonTonesG[] = {
  NOTE_G4, NOTE_A4, NOTE_B4, NOTE_C5,
  NOTE_D5, NOTE_E5, NOTE_FS5, NOTE_G5
};
const int numTones = sizeof(buttonPins) / sizeof(buttonPins[0]);

void setup() {
  sensorvalue = 0;
  for (uint8_t i = 0; i < numTones; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);//输入模式，使用上拉电阻
  }
  pinMode(SPEAKER_PIN, OUTPUT);
}

void loop() {
  int pitch = 0;
  int switchstate = digitalRead(A0);
  sensorvalue = digitalRead(A0);//analogRead(A0);
  if (switchstate == LOW) {
    for (uint8_t i = 0; i < numTones; i++) {
      analogWrite(13, 0);
      if (digitalRead(buttonPins[i]) == LOW) {
        pitch = buttonTonesC[i];
      }
    }
  } else {
    analogWrite(13, 255);
    for (uint8_t i = 0; i < numTones; i++) {
      if (digitalRead(buttonPins[i]) == LOW) {
        pitch = buttonTonesG[i];
      }
    }

  }
  if (pitch) {
    tone(SPEAKER_PIN, pitch);
  } else {
    noTone(SPEAKER_PIN);
  }
}