Ultra Sensor Distance Flag!

1// ---------------------------------------------------------------- //
2//  Arduino Ultrasoninc Sensor HC-SR04
3// Re-writed by Arbi Abdul Jabbaar
4// Using  Arduino IDE 1.8.7
5// Using HC-SR04 Module
6// Tested on 17 September 2019
7//  Modified by tinker_knight 7 of October 2021
8// ----------------------------------------------------------------  //
9#include <Servo.h> // includes the servo library
10
11#define echoPin 2  // attach pin D2 Arduino to pin Echo of HC-SR04
12#define trigPin 3 //attach pin  D3 Arduino to pin Trig of HC-SR0
13
14// defines variables
15long duration; //  variable for the duration of sound wave travel
16int distance; // variable for  the distance measurement
17Servo myservo; // defines the Servo motor as "myservo"
18
19void  setup() {
20  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
21  pinMode(echoPin,  INPUT); // Sets the echoPin as an INPUT
22  Serial.begin(9600); // // Serial Communication  is starting with 9600 of baudrate speed
23  Serial.println("Ultrasonic Sensor  HC-SR04 Test"); // print some text in Serial Monitor
24  Serial.println("with  Arduino UNO R3");
25  myservo.attach(7); // tells the arduino that the servo,  myservo, is attached to pin 7
26}
27void loop() {
28  // Clears the trigPin condition
29  myservo.write(0); // sets the servo to 0 degrees
30  digitalWrite(trigPin, LOW);
31  delayMicroseconds(2);
32  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
33  digitalWrite(trigPin, HIGH);
34  delayMicroseconds(10);
35  digitalWrite(trigPin,  LOW);
36  // Reads the echoPin, returns the sound wave travel time in microseconds
37  duration = pulseIn(echoPin, HIGH);
38  // Calculating the distance
39  distance  = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
40  //  Displays the distance on the Serial Monitor
41  Serial.print("Distance: ");
42  Serial.print(distance);
43  Serial.println(" cm");
44
45  if (distance <  30) {
46    myservo.write(90); // raises the servo to 90 degrees
47    delay(3000);  // keep this delay the same so the ultra sensor won't slow down!
48    myservo.write(180);  // lowers the servo back to normal
49  }
50}