Design and Construction of a Home Automation System Using a Smart Phone

Home automation system involves introducing a level of computerized or automatic control to certain electrical and electronic systems in the home. These include lighting, temperature control, and so forth.This project is aimed at designing and constructing a microcontroller based home automation system, used to turn on and off the home electrical appliances when the temperature rises above or falls below a preset temperature range (between 25oC and 30oC). The inputs signals from both the temperature sensor LM35 and the signal sent from the bluetooth connection of the Android smart phone to the HC-05 Bluetooth Module serves as inputs to the microcontroller. Output units which comprise of the Liquid Crystal Display (LCD) and the relays which powers on and off the fan and bulbs, are incorporated in the circuit to make the results of test visible and complete the system design for the smart home. The result of the test shows that the system automatically switched on and off light bulbs, turned on sockets and a.c fans at the preset temperature value (below 25oC and above 30oC) through the LM35 temperature sensor. And through the HC-05 bluetooth module the system was able to switch on and off the home appliances.Keywords: Home automation systems (HASs), Smart home, home appliances, Bluetooth, Androi