#include <Servo.h>

Servo myservo;  // create servo object to control a servo

int led = 11;
int potpin = 0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin
String str = "";

void setup() {
  Serial.begin(9600);
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  pinMode(led, OUTPUT);
}

void loop() {
  ledWrite(str);
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  Serial.println((float)val*5/1024);
  val = map(val, 0, 1023, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(1000);                           // waits for the servo to get there
}
void ledWrite(String val)
{
  while(Serial.available()>0){
    val += char(Serial.read());
    delay(20);
  }
     if(val.length()>0){
        Serial.println("str:"+val);
     
        if(val.compareTo("open")>0){
          digitalWrite(led,HIGH);
          Serial.println("LED已经点亮！");
        }

        else if(val.compareTo("close")>0){
          digitalWrite(led,LOW);
          Serial.println("LED已经熄灭！");
     }
   }
   val = "";

}