ultrasonic-led.ino

#include <Servo.h>

const int trigPin = 2;
const int echoPin = 3;

long duration;
int distance;
Servo myServo;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
  myServo.attach(5);
}

void loop() {
  for (int i = 15; i <= 165; i++) {
    myServo.write(i);
    delay(30);
    distance = calculateDistance();

    Serial.print(i);
    Serial.print(",");
    Serial.print(distance);
    Serial.print(".");
  }

  for (int i = 165; i > 15; i--) {
    myServo.write(i);
    delay(30);
    distance = calculateDistance();

    // cm
    long cm = distance / 29.1;
    if (cm >= 20) {
        digitalWrite(8, HIGH);
        digitalWrite(9, LOW);
        digitalWrite(10, LOW);

    //
    } else if (distance >= 15) {
        digitalWrite(8, LOW);
        digitalWrite(9, HIGH);
        digitalWrite(10, LOW);
    } else {
        digitalWrite(8, LOW);
        digitalWrite(9, LOW);
        digitalWrite(10, HIGH);
    }

    Serial.print(i);
    Serial.print(",");
    Serial.print(distance);
    Serial.print(".");
  }
}

int calculateDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;
  return distance;
}