[FAQ] TMP112: Arduino or Energia Example

This example also applies to TMP102.

#include <Wire.h>
#define TMP112Addr 0x49
/* Address Pin Options:
 *  GND 1001000 0x48
 *  V+  1001001 0x49
 *  SDA 1001010 0x4A
 *  SCL 1001011 0x4B
 */
void setup() {
  Wire.begin();
  Serial.begin(9600);
}

void loop() {
  Wire.beginTransmission(TMP112Addr);
  Wire.write(0x0); /* Write Pointer=0 to select Temperature Register */
  Wire.endTransmission();
  Wire.requestFrom(TMP112Addr, 2); /* Request 2 bytes */
  int16_t ret = (Wire.read() << 8) | Wire.read();
  float tempC = (ret >> 4) * 0.0625;
  Serial.println(tempC);
  delay(500);
}

This will print temperature in degrees celsius to the Serial Monitor. It's important to note that storing/casting the 16 bit result in a signed 16 bit data type will correctly convert it to a negative number as appropriate. Here is the Serial Plotter showing a shot of freeze spray applied to the sensor, with negative temperatures correctly decoded: