GSM-Based Remote Control System for Household Electrical Appliances in Enugu State

This project designs and implements a GSM-based remote control system that enables users to switch household electrical appliances on and off through standard mobile phone text messages from any location in Enugu State, South East Nigeria. The proliferation of mobile telephone networks across Nigeria, including in semi-urban and peri-urban areas, makes GSM-based home automation a practically accessible and cost-effective alternative to internet-dependent smart home platforms. The system uses a SIM800L GSM module interfaced with an Arduino Uno microcontroller to receive and parse SMS commands. Upon successful authentication of the sender's phone number, the microcontroller activates the appropriate relay channel to switch the designated appliance. Up to eight appliances can be controlled independently through a relay module board. A status feedback mechanism enables the system to send a confirmation SMS indicating the current state of each controlled appliance. Security is maintained through a personal identification number embedded in the command message structure. A prototype was assembled and validated in a residential building in Enugu, demonstrating reliable switching with an average command execution latency of under three seconds across a range of network conditions. The system was tested with fans, lighting circuits, and a water pump. Power consumption of the control unit was measured at 2.1 watts in idle mode, making it suitable for continuous standby operation. The project identifies network dead zones as the primary limitation and recommends future integration with a Wi-Fi fallback module. Keywords: GSM remote control, home automation, Arduino, relay switching, Enugu State.