P10 LED MATRIX BOARD DISPLAY

Here in this project I have used 12 P10 led matrix board in array of 4 horizontal and 3 vertical ie 4 columns and 3 row.
All displays are cascaded ,while last one become the origin or 0,0.

You need a long flat cable of 16 pin connector for connecting the display on different line as suggested in the figure.

I have used the DMD library by freetronics.

First I have planned to display time temperature one the first line, display two messages scrolling in line two and three.

I have used LM35 as temperature sensor which gives 10mV per degree change in celsius scale and used 1.1V as ADC reference for maximum resolution. 

DS1307 as RTC with IIC interface, but the problem is whenever is use DMD with IIC, I dont know why the time value of RTC is not stable its always changing like it gives right time for 3 or 5 times and then 165 165 and 85. May be due to some conflict on resources couldnt really figure out.

Solve this problem using two controller using one as just display drivers and second sending all data of temperature, time, font, writing message , reading message and saving message and controlling the speed of the message scroll.

Here's the link to the code final code https://github.com/kieran-shrestha/led_notice_board

INTERFACING ADC OF AVR MICROCONTROLLER

The following is the code for using the internal 10 bit ADC of AVR microcontroller.
The code is written for ATMEGA328 with system clock of 16MHZ.
The code uses standard c header files for using printf function and then print the content in serial uart of the microcontroller.