RTC based Countdown Timer for Exam

This project implements a Real-Time Clock (RTC)-based countdown timer specifically designed for exams. The system is built using an Atmega328 microcontroller, a DS1307 RTC module, an I2C-based LCD display, and a MAX7219-based 7-segment LED display. The countdown timer allows users to set the exam duration using a potentiometer and initiate the countdown with a push button. The system continuously displays the real-time clock and date on the LCD while also showing the countdown timer on the MAX7219 7-segment display. A buzzer provides audio feedback at key moments such as countdown initiation, completion, and time adjustments. The system includes an interactive date and time-setting mechanism controlled via tactile push buttons. For power, the system utilizes a 12-0-12 step-down transformer, a center-tap rectifier with 1N4007 diodes, and voltage regulation via a 7805 regulator with capacitors for stability. The setup ensures reliable operation with an uninterrupted power supply