Lazy Robot V1 - Część 4/8 - Czujnik ultradźwiękowy HC-SR04

Podłączenie i test ultradźękowego czujnika odległości HC-SR04


Schemat podłączenia ulradźwiękowego czujnika odległości HC-SR04:

Kod źródłowy:

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#define ULTRASONIC_TRIG_PIN 11 /* Define witch pin will be HC-SR04 TRIG */
#define ULTRASONIC_ECHO_PIN 12 /* Define witch pin will be HC-SR04 ECHO */

int read_distance()
{
  long duration, distance;       /* Declarete duratuion and distance variable long type */
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);   /* Chance TRIG pin state to LOW       */
  delayMicroseconds(2);        /* Wait 2 miliseconds         */
  digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);   /* Chance TRIG pin state to HIGH      */
  delayMicroseconds(10);       /* Wait 10 miliseconds         */
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);   /* Chance TRIG pin state to LOW       */
  duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH); /* pulseln() on ECHO pin to HIGH      */
  distance = (duration/2) / 29.1;     /* distaince calculation        */
  
  if (distance >= 200 || distance <= 0)  /* If read value is >=200 or >=0 */
  {
    return 999;   /*  Function return 999 it's error (out of range)  */
  }
  else
  {
    return distance; /* Function return correct distaince     */
  }
}

void setup()
{
 Serial.begin(9600);  /* Initial serial port (COM) for arduino with 9600 bits per second speed */
 pinMode(ULTRASONIC_TRIG_PIN, OUTPUT); /* Set TRIG pin as output*/
 pinMode(ULTRASONIC_ECHO_PIN, INPUT); /* Set ECHO pin as input*/
}

void loop()
{
 Serial.println(read_distance()); /* Print for serial result of function read_distance() */
 delay(500);       /* Wait 0.5 second */
}

Opis funkcji pulseIn():
https://www.arduino.cc/reference/en/language/functions/advanced-io/pulsein/