This document describes an automatic room light intensity based window blinds control system that uses a light dependent resistance sensor to measure outdoor sunlight intensity and control a stepper motor to open or close window blinds. It aims to save 20-30% of household electricity costs by utilizing outdoor sunlight for indoor lighting. A microcontroller senses the sunlight level, determines the appropriate blind angle, and activates the stepper motor driver. The system is controlled with embedded C firmware on a PIC microcontroller for its integrated peripherals, high source/sink currents, and ease of development compared to assembly language.