The purpose of this thesis is aiming to develop a fully functioned and accurate smart meter in home automation system, which fulfils the requirements of home energy conservation and control in energy efficient strategy. Through smart meter applications, people can understand how energy is used and how to monitor and control the usages. Technique of transmitting data via power line (PL) is used already in many energy applications. This work discusses the current state of the power line carrier communication and the complement of solid-state relay, which is designed as external part for smart meter application. This design based on the single-chip AVR465 which is a microcontroller chip used for single phase power meter with tamper logic. The core can store large amounts of information and measurement with the measuring results in real-time analysis, comprehensive and make a judgment apparatus. The design has been implemented with C language and the related applications have been implemented using QT, Javas Script, HTML, PHP, jQuery, mySQL database and FTP protocol. Furthermore, the measurements have were correct and within the range of accuracy.