const int RELAY_PIN = 7;//输出7引脚,给继电器的输入用的
const int THRESHOLD = 215;  // 根据实际情况设置光照阈值
void setup() {
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(A0, INPUT);//A0读取光敏电阻的输入
}
void loop() {
  int lightValue = valueToLightValue();
  if (lightValue < THRESHOLD) {
    digitalWrite(RELAY_PIN, HIGH); // 打开继电器，发光二极管亮起
  } else {
    digitalWrite(RELAY_PIN, LOW);  // 关闭继电器，发光二极管熄灭
  }
  delay(100);  // 延迟一段时间进行下一次光照检测
}
//从读取过来的值转换为光强值（lux）
//换算公示文档抄来的：https://docs.wokwi.com/zh-CN/parts/wokwi-photoresistor-sensor#%E5%B7%A5%E4%BD%9C%E6%96%B9%E5%BC%8F
int valueToLightValue() {
  // These constants should match the photoresistor's "gamma" and "rl10" attributes
  const float GAMMA = 0.7;
  const float RL10 = 50;
  // Convert the analog value into lux value:
  int analogValue = analogRead(A0);//A0读取光敏电阻的输入
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
  return lux;
}