For my AquaTank Control V2 project this is a necessary thing,
Arduino board can count time very well, BUT, as soon as you disconnect it goes back to zero.

This is where the DS1302 kicks in.
I bought it on ebay – Link
and decided to go for the Surface Mounted one to save space in my future project


So here is a hook up guide and integration with my project

The DS1302 connect to the arduino using 3 digital pins like this:


Or any other Pins, you will define this in the code.

The Code

Using the DS1302 Arduino library by Henning Karlsen.
The example code displaying the time with the serial monitor:

Please note once you have flashed the arduino once with the correct time you should comment out (add // in front) or delete lines 23-25 and flash it again:

//rtc.setDOW(FRIDAY); // Set Day-of-Week to FRIDAY
//rtc.setTime(12, 0, 0); // Set the time to 12:00:00 (24hr format)
//rtc.setDate(6, 8, 2010); // Set the date to August 6th, 2010


Integrating DS1302 RTC with 12864 LCD:

And the result:


Have Fun Doing it Yourself 🙂