      timeold = millis();
      ipm = rpm*2.0*pi*r; //inches per minute
      car_speed = ((ipm*60)/12)/5280;
-
-     Serial.printf("%d,%d", rpm, car_speed);
-     
+     data = String(rpm);
+     data.concat(",");
+     data.concat(String(car_speed));
      revs = 0;
+     Serial.println(data);
    }
   }
   

 double curtime;
 double ms;
 double minutes;
 
  void setup()
 {

 
 void loop()//Measure RPM
 {
   time_dif = millis() - curtime;
   
   if (time_dif>100) {
     curtime = millis();
     ms = curtime - timeold;
     minutes = ms/1000/60;
