BluetoothTemperature.ino

#include <Wire.h>
#include <SoftwareSerial.h>

int tmp102Address = 0x48;
SoftwareSerial bleShield(2, 3);

long interval = 1000; 

void setup(){
  Serial.begin(19200);
  bleShield.begin(19200);
  Wire.begin();
}

void loop()
{
  digitalWrite(13, HIGH);   // set the LED on

  bleShield.print(temperatureString());
  Serial.println(temperatureString());

  delay(interval);         // wait for 1 sec
  digitalWrite(13, LOW);   // set the LED off
}

String temperatureString() 
{
  char temp[10];
  float celsius = getTemperature();
  dtostrf(celsius,2,2,temp);
  String tempAsString = String(temp);
  
  String s = "" + tempAsString + " C                         ";
  return s.substring(0,16);
}

float getTemperature(){
  Wire.requestFrom(tmp102Address,2); 

  byte MSB = Wire.read();
  byte LSB = Wire.read();

  //it's a 12bit int, using two's compliment for negative
  int TemperatureSum = ((MSB << 8) | LSB) >> 4; 

  float celsius = TemperatureSum*0.0625;
  return celsius;
}