SEG (Smart energy energy) is a prototype, built with an Arduino, measures in real time the voltage, current, power, and energy of connected devices (fan, lamp). An ultrasonic sensor detects presence: if someone is there, the system powers the devices; if not, it cuts the relay and signals absence with LEDs and a buzzer. It shows how to monitor and reduce electricity use while improving safety and automation in a small system — a base for more advanced energy-saving solutions.