This paper presents an implementation of a home automation system using smart phone Bluetooth with Arduino for the switching and control of home appliances. It aimed at reducing stress for the physically challenged, elderly, and younger children with an easy control of the home appliances and likewise reduction of risk of electrocution from the source of control. With this automated control unit, users can comfortably operate their electrical installations or appliances from distances ranging from 30 m to 100 m away from the point of control using smart phone. The control unit comprises a four-channel relay module, an Arduino Uno board (AUB) based on the ATmega328 microcontroller, an HC-05 Bluetooth module, and a manual backup switch or alternative. The central processing unit is the Arduino Uno board to which every other component is connected. The Load (devices/appliances) to be controlled or operated is connected to the Arduino Uno board (AUB) via the relay. The Arduino board is programmed using the Arduino integrated development environment (IDE), with instructions that controls other units of the circuits. An Arduino Bluetooth controller is installed on the phone, to be used as a remote controller and to enable communication interface between the phone and the Arduino based control unit. In other words, the Bluetooth module connected to the Arduino board receives signals and/or instructions through phone Bluetooth via controller installed on the phone. An LCD (led crystal display) is used as display output of information uploaded on the Arduino Uno board to know the working state of the circuit. It was found that the automated control unit is of great benefit to users in terms of convenience in operating their appliances, including the elderly, and physically challenged people as it reduces their stress and difficulty in moving from point to point in order to control their home lightings and appliances.
