// create code Programming c++ Design phase control HC-SR04 Setup to config
// TRIG >> OUTPUT
// ECHO << INPUT

long duration = 0;
int cm = 0;
int inch = 0;

int trig1 = 3 ;
int echo1 = 2 ;

int trig2 = 5 ;
int echo2 = 4 ;

int trig3 = 6 ;
int echo3 = 7 ;

int trig4 = 9 ;
int echo4 = 8 ;


void setup() {
  Serial.begin(9600);
  pinMode(trig1, OUTPUT);
  pinMode(echo1, INPUT);
  pinMode(trig2, OUTPUT);
  pinMode(echo2, INPUT);
}

void loop() {
  phase1();
  phase2();
  delay(500);
}

void phase1() {
  digitalWrite(trig1, LOW);
  digitalWrite(trig1, HIGH);
  digitalWrite(trig1, LOW);

  duration = pulseIn(echo1,HIGH);
  cm = duration*0.034/2;
  inch = duration*0.0133/2;
  Serial.print("echo1: ");
  Serial.println(cm);

  delay(100);
}

void phase2() {
  digitalWrite(trig2, LOW);
  digitalWrite(trig2, HIGH);
  digitalWrite(trig2, LOW);

  duration = pulseIn(echo2,HIGH);
  cm = duration*0.034/2;
  inch = duration*0.0133/2;
  Serial.print("echo2: ");
  Serial.println(cm);

  delay(100);
}

void phase3() {}

void phase4() {}