DS1302 based Digital Clock with Calendar

 

using:

1. DS1302 as Time keeping IC
   
2. Interrupt based keypad

The DS1302 trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface. The real-time clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator. DS1302 communicates with a microcontroller using a 3 wire interface very similar to SPI. So this is one new thing to learn in this project.

Now a second interesting thing that got my attention is the interrupt based keypad. All codes we have seen till now use keypad scanning. This one uses an interrupt based approach for scanning keys. As soon as a key an interrupt is generated through an AND gate connected to all the rows, which indicate to the controller that a key is pressed. So scanning is done in ISR routine where the key is detected. I am sure this way of using a keypad must be helpful for many of us when making our new projects.

circuit diagram :

code and circuit diagram is available in the link given below 

You can download this project from the link below