The body temperature is measured using DS 1620 IC from Maxim Industries. It is a digital thermometer and thermostat. It supports two modes: Stand-alone mode and 3-Wire Interface mode. The latter is used when the DS 1620 is used in combination with a microcontroller or micro-processor to allow synchronous serial data transfer whereas the former is used in absence of any such component and when it acts as a thermostat. Here the temperature is read as 9-bit values through the 3-wire serial interface.