#include <Adafruit_SSD1306.h>
#define RESET LED_BUILTIN
Adafruit_SSD1306 oled(RESET);
const int trigPin= 8;
const int echoPin = 9;
long duration;
int distanceCm;

void setup() 
{
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  oled.begin(SSD1306_SWITCHCAPVCC, 0x3c);
  oled.setTextSize(1);
  oled.setTextColor(WHITE);
  oled.display();
  delay(1000);
  oled.clearDisplay();
}

void loop() 
{
  digitalWrite(trigPin, LOW);
  delayMicroseconds(1);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration=pulseIn(echoPin,HIGH);
  distanceCm=duration *0.034/2;
  oled.clearDisplay();
  oled.setCursor(0,0);
  oled.print("ULTRASONIC");
  oled.setCursor(0,10);
  oled.print("SENSOR");
  oled.setCursor(0,20);
  oled.print(distanceCm);
  oled.print(" cm");
  oled.display();
  delay(1000);
}