int trig=12;     // GPIO Pin D6

int echo=14;     //GPIO Pin D5

int time_microsec;

int time_ms;

int dist_cm;

void setup() {

  // put your setup code here, to run once:

  Serial.begin(9600);

  pinMode(12,OUTPUT);

  pinMode(14,INPUT);

}

void loop() {

  // put your main code here, to run repeatedly:

digitalWrite(trig,LOW);

delayMicroseconds(2);

digitalWrite(trig,HIGH);

delayMicroseconds(10);

digitalWrite(trig,LOW);

//pulseIn gives time in micro seconds, 1Sec= 1000000 microseconds

time_microsec= pulseIn(echo,HIGH);

time_ms=time_microsec/1000;

dist_cm= (34*time_ms)/2;

Serial.print("Time to travel: ");

Serial.println(time_ms,1);

Serial.print("ms / ");

Serial.print("Distance: ");

Serial.print(dist_cm,1);

Serial.print("cm ");

delay(2000);

DIAGRAM