#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#define OLED_ADDR   0x3C    // OLED display TWI address
Adafruit_SSD1306 display(-1);
#define ECHpin 6
#define TRIGpin 7
unsigned long duree ;
const float SOUND_SPEED = 343.00 / 1000;
float distance = 0.00;

void setup() {
 pinMode(ECHpin, INPUT);
 pinMode(TRIGpin, OUTPUT);
 digitalWrite(TRIGpin, LOW);
 Wire.begin( );                // démarre la communication I2C
 display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR); // initialize l'ecran OLED
 display.clearDisplay();     //efface l'affichage OLED
 display.display(); 
}

void loop() {
 digitalWrite(TRIGpin, HIGH);
 delayMicroseconds(10);
 digitalWrite(TRIGpin, LOW);
 // mesure du temps aller retour de l'impulsion US
 duree = pulseIn(ECHpin, HIGH);
 distance = duree  * SOUND_SPEED / 2.0 ;
 display.clearDisplay();
 display.display();  
 display.setTextColor(WHITE);
 display.setTextSize(1);
 display.setCursor(35,1);    
 display.print("DISTANCE" );
 display.display(); // actually display all of the above 
 display.setTextSize(2);
 display.setCursor(10,17);    
 display.print(distance);
 display.setCursor(85,17);    
 display.print(" mm");
 display.display();
 delay(5000);
}