 String packet ;
 
 void setup() {
-  pinMode(16,OUTPUT);
-  pinMode(2,OUTPUT);
+  pinMode(16,      OUTPUT);
+  pinMode(2,       OUTPUT);
+  pinMode(trigPin, OUTPUT);
+  pinMode(echoPin, INPUT);
   
   digitalWrite(16, LOW);    // set GPIO16 low to reset OLED
   delay(50); 

#include <Wire.h>  
#include "SSD1306.h"

#define echoPin D7 // Echo Pin
#define trigPin D6 // Trigger Pin

/////////////////////////////////////////////////////////////
#define SCK     5    // GPIO5  -- SX1278's SCK

  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH);
  //Calculate the distance (in cm) based on the speed of sound.
  int distance = duration/58.2 + 1;
  return distance;
}

