Temperature controller using PIC / Nur Zaidi Mohamed Yusup

Engineering is concerned with the understanding and controlling the mate,ials and forces of nature for the benefit of mankind. Controllers are devices which create changes, known as system response according to feedback information. Controllers play the critical role of maintaining the desired conditions. Presented in the project 1s a simple temperature controller alarm which uses a PIC 16F873 microcontroller and a 2-line LCD display. The LCD displays current temperature, temperature set pointing in Celsius degrees, duration of time in second and alarm displays. Features are a 5-key keypad which allows user to set independent high and low temperature alarm points and time duration also a buzzer to indicate when the controlling is finished. This project used a PIC to automate the controlling process of heater and fan. A microcontroller is used as it has the advantage of fast design time, no need to design & built interfacing circuits, no compatibility problems, can be interfaced to anything and easy to determined external peripheral timing. The input signals from the sensors ( thermostat ) are electronically processed and fed into the control system, which determines the action to be taken. An appropriate signal is then given to the actuators, which make the desired changes in the system, such as reducing, maintaining and increasing the heat input also turning on and off the fan . Thermostat control is used in cooling and heating systems to ensure that desired conditions are maintained.