초음파 센서 이용하기

초음파 센서로 간단하게 거리를 측정하는 코드입니다.

Trig핀으로 신호를 보내고 Echo핀으로 측정값을 받습니다.

측정된 값을 왕복이니깐 2로 나누고, 소리는 초당 343m를 이동하므로, 1cm를 이동하는데 29.155ms가 소요되므로 29.1을

나누어 줍니다.

http://www.instructables.com/id/Simple-Arduino-and-HC-SR04-Example/

/*

HC-SR04 Ping distance sensor]

VCC to arduino 5v GND to arduino GND

Echo to Arduino pin 13 Trig to Arduino pin 12

Red POS to Arduino pin 11

Green POS to Arduino pin 10

560 ohm resistor to both LED NEG and GRD power rail

More info at: http://goo.gl/kJ8Gl

Original code improvements to the Ping sketch sourced from Trollmaker.com

Some code and wiring inspired by http://en.wikiversity.org/wiki/User:Dstaub/robotcar

*/

#define trigPin 13

#define echoPin 12

#define led 11

#define led2 10

void setup() {

  Serial.begin (9600);

  pinMode(trigPin, OUTPUT);

  pinMode(echoPin, INPUT);

  pinMode(led, OUTPUT);

  pinMode(led2, OUTPUT);

}

void loop() {

  long duration, distance;

  digitalWrite(trigPin, LOW);  // Added this line

  delayMicroseconds(2); // Added this line

  digitalWrite(trigPin, HIGH);

//  delayMicroseconds(1000); - Removed this line

  delayMicroseconds(10); // Added this line

  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);

  distance = (duration/2) / 29.1; // 소리는 초당 343m를 이동하므로, 1cm를 이동하는데 29.155ms가 소요됨

  if (distance < 4) {  // This is where the LED On/Off happens

    digitalWrite(led,HIGH); // When the Red condition is met, the Green LED should turn off

  digitalWrite(led2,LOW);

}

  else {

    digitalWrite(led,LOW);

    digitalWrite(led2,HIGH);

  }

  if (distance >= 200 || distance <= 0){

    Serial.println("Out of range");

  }

  else {

    Serial.print(distance);

    Serial.println(" cm");

  }

  delay(500);

}