const int BUTTON_PIN = 7;  // 按钮的引脚
const int LED_PIN =  3;    // LED灯的引脚

int buttonState = 0;       // 按钮状态
int lastButtonState = HIGH; // 上一次按钮状态
unsigned long lastDebounceTime = 0;  // 上一次读取按钮状态的时间
unsigned long debounceDelay = 20;    // 消抖延迟时间

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);   // 设置LED的引脚为输出
  pinMode(BUTTON_PIN, INPUT_PULLUP); // 设置按钮的引脚为输入，因为我们要读取它的状态
}

void loop() {
  int reading = digitalRead(BUTTON_PIN);  // 读取按钮的状态

  // 检查是否需要进行按钮消抖
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }
  Serial.print("lastDebounceTime:");
  Serial.println(lastDebounceTime);
  Serial.print("millis():");
  Serial.println(millis());
  
  // 如果时间间隔大于消抖延迟时间，更新按钮状态
  if (millis() - lastDebounceTime > debounceDelay) {
    // 只有当按钮状态发生改变时才进行处理
    if (reading != buttonState) {
      buttonState = reading;

      // 检测到按钮按下事件
      if (buttonState == LOW) {
        // 切换LED灯状态
        Serial.print("灯状态:");
        Serial.println(!digitalRead(LED_PIN));
        Serial.print("开关状态:");
        Serial.println(digitalRead(BUTTON_PIN));
        digitalWrite(LED_PIN, !digitalRead(LED_PIN));
      }
    }
  }

  // 更新上一次按钮状态
  lastButtonState = reading;
}