AN AUTOMATED ROOM TEMPERATURE CONTROLLER

Abstract

ABSTRACT This project work presents the design of an automated room temperature controller system. This system allows the user to set a desired temperature which is then compared to the room temperature measured by DHT11 temperature sensor. With the help of Atmega 328 based on Arduino microcontroller, the system responds by turning ON and OFF the two (2) loads (fan or a heater) automatically depending on the temperature difference in the room. The fan is triggered ON when the room temperature is higher than the set temperature and the heater is triggered ON when the room temperature is lower than the set temperature. The system was designed and simulated using Proteus 8, circuit building software used for building electronics system. Proteus software was used to design and simulate the main circuit; Arduino IDE was used to write a program on how the system will operate which was then loaded to the microprocessor. An LCD was used to display temperature readings obtained by the DHT11 temperature sensor and the condition of the heater and the fan whether ON or OFF. A digital multimeter was then used to take the voltage readings across the heater and the fan. When the system was simulated the heater and the fan were turned on automatically depending on the room temperature. The heater turned on when the temperature was below 27 degree Celsius while the fan turned on when temperature fell below the threshold. In both cases, either of them was on at a specified time but not both. When the heater was on the fan was off and vice versa. KEYWORDS : Arduino, Automation, threshold value, temperature