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 oC to 125oC for the ambient temperature and -70 oC to 382.19oC 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
Highlights
Thermometer is an instrument used in measuring the temperature
The MLX90614 is factory calibrated in wide temperature ranges from -40oC to 125oC for the ambient temperature and -70oC to 382.19oC for object temperature
While monitoring temperature and telling time, the microcontroller sends the measurements in form of digital signal to the liquid crystal display (LCD) for display.The LCD displays the temperature parameters measured and tells time continuously until a fault occurs.The circuit diagram of the digital thermometer with clock is shown in figure 4
Summary
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”. 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). Temperature measuring devices are used in medical/fitness equipment, human body temperature monitoring, industrial applications (e.g. fractional distillation processes), and in research laboratories, such as chemical and chemistry laboratories (Abayomi et al, 2013). Before this time, temperature has been measured using analogue meter. Mercury-in-glass thermometers were used for temperature measurements only while separate instruments were required for checking the time. It presents the design and implementation of a digital thermometer with clock to monitor the temperature of a system while checking the time/period at which the measurement is made
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have