Introduction: Adding an ATMEGA328P and Real Time Clock to an Existing Project

About: Why would i buy something ready made when i can make it myself with half the features for twice the money? DIY!
This was an existing project i had made some time before.
An 8 X 10 LED matrix.

So it is not a complete build, just showing the add on
 
I have added to the 8 X 10 LED display a micro-processor, the ATMEGA328P running at 8MHz internal clock with Arduino bootloader.
Also a DS1307 Real Time Clock.
You can also see the programming header installed.

Supporting info:
here
here

Step 1: Programming

To program i used the methods found:
here
here
here

 

Step 2: Pin Connections

From the 74HC595 shift register to the 328P micro-processor the pins to connect are:. 

Pin 14 to 15
Pin 12 to 17
Pin 11 to 16.

From the CD4017 decade counter to the 328P micro-processor the pins to connect are:

Pin 15 to 18
Pin 14 to 19.

Pin connections for the RTC to the 328P ,icro-processor are
:
SDA to pin 27
SCL to pin 28 

Ground and VCC +5v will need to be connected as well.

Step 3: Code

This is the code i used.

I couldn't copy and past so it is in a attached file.