초음파 센서(HC-SR04)
초음파 센서 (Ultrasonic sensor, HC-SR04)
출처: https://www.indiamart.com
초음파를 이용, 거리를 측정할 수 있는 센서로
음파를 쏘고 받는데 걸린 시간차로 거리를 측정 합니다
원리는 매우 단순하지만, 물체크기를 알 수 없고
난반사로 측정값이 높은 확률로 달라질수 있습니다
pinmap
souce
// ---------------------------------------------------------------- //
// Arduino Ultrasoninc Sensor HC-SR04
// Re-writed by Arbi Abdul Jabbaar
// Using Arduino IDE 1.8.7
// Using HC-SR04 Module
// Tested on 17 September 2019
// https://create.arduino.cc/projecthub/abdularbi17/ultrasonic-sensor-hc-sr04-with-arduino-tutorial-327ff6
// ---------------------------------------------------------------- //
#define echoPin 2 // attach pin D2 Arduino to pin Echo of HC-SR04
#define trigPin 3 //attach pin D3 Arduino to pin Trig of HC-SR04
// defines variables
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
void setup() {
pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
Serial.println("Ultrasonic Sensor HC-SR04 Test"); // print some text in Serial Monitor
Serial.println("with Arduino UNO R3");
}
void loop() {
// Clears the trigPin condition
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin HIGH (ACTIVE) for 10 microseconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculating the distance
distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
// Displays the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");
}