int sp1=7;//Define the servo port pin 
int pulsewidth;//Define the pulse width
int val;
int val1;
int myangle1;

//servopulse function
void servopulse(int sp1,int val1)//Define a pulse function
{
  myangle1=map(val1,0,180,500,2480);
  digitalWrite(sp1,HIGH);//Set the servo port to high
  delayMicroseconds(myangle1);//Delay time
  digitalWrite(sp1,LOW);//Set the servo port to low
  delay(20-val1/1000);
}

void setup()
{
  pinMode(sp1,OUTPUT);//Set the servo port as output
  //Set the baud rate
  Serial.begin(9600);
  delay(500);
  Serial.println("servu=o_seral_simple ready" ) ;
}

void loop()//Map the number 0 to 9 as the Angle of 0 to 180, and let LED flashing the corresponding number
{
  val=Serial.read();//Read the serial port value
  
  if(val>'0'&&val<='9')
  {
    val1=val-'0';//Get the pure number
    val1=map(val1,0,9,0,180);//Convert angle to pulse width value of 500-2480
    Serial.print("moving servo to ");
    Serial.print(val1,DEC);
    Serial.println();
    for(int i=0;i<=50;i++)//Given enough time to make servo to rotate specified angle
    {
      servopulse(sp1,val1);//Invoke the pulse function
    }
  }

}