 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); 


void loop() {
  int distance = checkDistance();
  sendPacket("W:" + distance);

  delay(10000);
}

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

#define echoPin 12 // Echo Pin
#define trigPin 13 // Trigger Pin

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