An Automated Room Temperature Controller

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