The Smart Alarm System is an embedded security solution designed to monitor environmental conditions and detect suspicious activity in real time. The system combines multiple hardware and software components in order to improve safety and provide fast user notifications in critical situations.

The project uses motion detection sensors and ambient light monitoring to determine whether an event should be considered dangerous, such as movement detected during nighttime. When suspicious activity is identified, the system activates visual and sound alarms using LEDs and a PWM-controlled buzzer. In addition, the device communicates through Bluetooth, allowing the user to access system logs and monitor alerts directly from a mobile phone using commands such as GETLOG.

The purpose of this project is to create a low-cost, efficient, and extensible smart security platform while applying embedded systems concepts such as ADC, PWM, interrupts, UART communication, and wireless connectivity.

• ATmega328P microcontroller
• PIR motion sensor
• Light sensor (LDR)
• Buzzer controlled through PWM
• Status LEDs
• Bluetooth module
• Power supply module