Digital Alarm Clock Using 7 Segment Display




About: Enjoys learning and playing with electronics and programming.

This project has a few basic functions which is clock display, countdown timer, stopwatch, temperature display and time settings. The controller used in this project is an Arduino Uno made by myself on a PCB.

The 7 segment display uses 74HC595 Shift Register to create more outputs and control each segments. Multiplexing method is used to control each 7 segment display.

The clock information is obtained from DS1307 Real Time Clock IC. The benefits of using DS1307 is that the clock information will continue ticking even the main supply to Arduino is off. DS1307 uses I2C interface for communication.

A DIY 4x4 matrix keypad is used to allow user to control the functions of clock. 4x4 matrix keypad is control by a PCF8574A, 8 bit I/O expander. This IC also uses I2C interface for communication.

A video explaining about this project.
More info available at my personal blog,

I will try to update here once I have more free time. Hope you enjoy my project. :)

Check out an upgrade version of this project,



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    2 Discussions


    2 years ago

    do you have any step to do this project ? i mean like coding ,the instruction ,schematics circuit ,pcb circuit .i hope u can share it to us .tq


    5 years ago

    This is a really cool idea that could be expanded in. It would be nice if you could make full instructions and schematics. I can see this going into a nice enclosure when and if I make this some day. Nice job! (: