Arduino blinds protecting device.

                                                                                               Circuit Diagram                                                                                             Arduino code : const int trigPin = 9;const int echoPin = 10;const int buzzer = 11;               //  G.S Entertainments Blinds protector                                                                      //   title - Blinds protecting device// defines variableslong duration;int distance;                                                                              int safetyDistance;             void setup() {pinMode(trigPin, OUTPUT); // Sets the trigPin as an OutputpinMode(echoPin, INPUT); // Sets the echoPin as an Input                         pinMode(buzzer, OUTPUT);pinMode(ledPin, OUTPUT);Serial.begin(9600); // Starts the serial communication}  void loop() {// Clears the trigPindigitalWrite(trigPin, LOW);delayMicroseconds(2); // Sets the trigPin on HIGH state for 10 micro secondsdigitalWrite(trigPin, HIGH);delayMicroseconds(10);digitalWrite(trigPin, LOW); // Reads the echoPin, returns the sound wave travel time in microsecondsduration = pulseIn(echoPin, HIGH); // Calculating the distancedistance= duration*0.034/2; safetyDistance = distance;if (safetyDistance <= 30)   // You can change safe distance from here changing value Ex. 20 , 40 , 60 , 80 , 100, all in cm{  digitalWrite(buzzer, HIGH);  digitalWrite(ledPin, HIGH);}else{  digitalWrite(buzzer, LOW);  digitalWrite(ledPin, LOW);} // Prints the distance on the Serial MonitorSerial.print("Distance: ");Serial.println(distance);}