Digital Alarm Clock with Dual Time

The project introduces a dual time digital clock with alarm by using a 28-pin high performance PIC16F873A microcontroller.

Some features of this clock contains a leap year correction that is valid up to 2100, 12 hour/24 hour time format, alarm, dual time consisting of standard time plus another time, and counting for seconds, minutes, hours, days, months, and year. The 7 LEDs represent the day of the week.

The PIC16F873A with built-in Timer1 module is the main component of the circuit, which can be used easily for implementing a real-time clock, a watch crystal, and two capacitors. It is intended primarily for a 32 kHz crystal oscillator that provides the clocking and causes it to continue running even in SLEEP mode. The crystal will make the Timer1 to overflow in every two seconds since it is a 16-bit counter. An interrupt is generated by the Timer1 overflow and the clock will be updated in every interrupt.

For various operations of the clock, two keys are provided consisting of MODE key for changing the Standard Time, Alarm Time, Date and Month, Dual Time, and others while the ADJ key enters the Adjust Mode.

Rest of the project