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ABSTRACT
In this paper, the design of a digital thermometer with clock is presented. The design was achieved using ATMEGA 328P PU Microcontroller Unit, MLX90614 Infrared Sensor for achieving contactless measurement (wireless) and the DS1307 Real Time Clock (RTC) for accurate time keeping during the measurement of this parameter.The MLX90614 is factory calibrated in wide temperature ranges from - 40 °C to 125°C for the ambient temperature and -70 °C to 382.19°C for object temperature, while the DS1307 is a low-power clock/calendar with 56 bytes of battery-backed serial random access memory (SRAM). Power is supplied using a regulated 9 V DC battery. The microcontrollers and RTC chip are powered by 5 V DC. The temperature sensor and liquid crystal display (LCD) require 3.3 V DC for operation and are supplied by passing the 5 V DC through a variable resistor. The sensors output values are both fed into the microcontroller. While monitoring temperature and telling time, the microcontroller sends the measurements in form of digital signal to the LCDs for display.This design was compared with a standard infrared thermometer by taking the body temperature measurements of two individuals at different times of the day. It was observed from the results that the difference between the temperature readings of the two thermometers ranges from 0 to 1 °C
KEYWORDS: Infrared sensor, digital thermometer, microcontroller, real time clock, temperature.
INTRODUCTION
Thermometer is an instrument used in measuring the temperature. The name thermometer is coined from the Greek words thermo, meaning "warm", and meter, meaning "to measure". So thermometers measure temperature by using materials that change in some way when they are heated or cooled (Saidu et al, 2014; Bellis, 2011). Measurement of temperature has been a usual process since the early 11th century. Monitoring of temperature of a particular place or system is important so as to monitor the behavior of such a system (Med, 2002).
Temperature monitoring devices are of integrated technology and are found in the area of electronics, computers, material and information Engineering. They play an important role in the medical/patient simulation system (Péter & Balázs, 2009). With the help of the temperature monitoring device, a doctor can get a lot of information about the condition of health of the individual. Patients who...