Enterprise and Implementation of a Microcontroller-Based Digital Temperature Measurement System

Abstract

Precision temperature measurement is crucial in laboratory, industrial and household uses. Traditional mercury-based thermometers are mechanically fragile, slow in measurement times and not compatible with current digital electronics. This paper describes the design, construction and experimental validation of an inexpensive microcontroller-based digital temperature measuring system. A PIC16F877A microcontroller is used to monitor the real-time temperature of a specific location, interfacing with a precision temperature sensor LM35. The measured values are shown on a seven segment LED’s module and an audible alarm is included, which makes an immediate alert if the temperature exceeds a preset level.
The architecture includes hardware elements and software functions such as A/D conversion, signal processing, display control and the alarm logic. Experimental verification was achieved by comparing the temperature values of the proposed system with those obtained by a standard mercury thermometer in same situation. Two measurement methods were proved to be mutually in reasonable good; the relative error between them is less than 3% for measured temperature. The obtained MAPD of 4.69% reveals that the proposed design i accurate and reliable. The digital thermometer is compact, power saving, and easy to build. Given its acceptable accuracy and practical versatility, the presented unit can be used for temperature control applications in laboratory, industry and domestic environments.