serial communication between two arduino uno

Projects Programming
1

I'm trying communication between two arduino uno r3.
my panel display total p10 module is 25 used.
i trying 1st arduino uno - connected 13 p10 module.
2 nd arduino uno - connected 13 p10 module.

one hardware serial port from pc and two arduino uno board connected.

in programming ..
my question is how can i declare different board(slave no.) number ie. one arduino send string when
(take slave no. 1)and displayed on 13 dmd p10 module.
2nd arduino send string when (take slave no.2) and displayed on other 13 dmd p10 module .

my code is...

/*--------------------------------------------------------------------------------------

Serial Read and Display.

This project is designed to Read inputs from Serial and Display the input on a
Freetronic 32x16 Dot Matrix Display.

To wipe your existing String simply input a Tilda (~) into your Serial Command.

Note, for debugging purposes, Serial.print has been used in both the Stop Display
and Write Display loops. These can be removed.

--------------------------------------------------------------------------------------*/

/--------------------------------------------------------------------------------------
Includes
--------------------------------------------------------------------------------------/

#include <DMD.h>
#include <SPI.h> //SPI.h must be included as DMD is written by SPI (the IDE complains otherwise)
#include <TimerOne.h>
#include "SystemFont5x7.h"
#include "Arial_black_16.h"
#define DISPLAYS_ACROSS 13
#define DISPLAYS_DOWN 1
DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN);

int board;
char serIn[200]; // Allocate some space for the string

void ScanDMD()
{
dmd.scanDisplayBySPI();
}

void setup()
{

Timer1.initialize( 4000 );
Timer1.attachInterrupt( ScanDMD );
dmd.clearScreen( true );

Serial.begin(9600);

}

void loop()
{
if(Serial.available()) {
int chars_in = 0;
//board=Serial.parseInt();
//if (board==1)
// void serialFlush(){
while (Serial.available()>0 && chars_in<199){
serIn[chars_in] = Serial.read();
Serial.write( byte(serIn[chars_in]));
chars_in++;
}

serIn[chars_in+1] = '\0';

}

//dmd.clearScreen( true );
//dmd.selectFont(Arial_Black_16);
dmd.selectFont(SystemFont5x7);

dmd.drawString(0, 0, serIn, 200, GRAPHICS_NORMAL );

dmd.drawString(0, 8, serIn+70, 200, GRAPHICS_NORMAL );

delay(1000);

}

please,reply for solve this problem.

2

Use code tags!
And post a wiring diagram!

3

lectrotek:
I'm trying communication between two arduino uno r3.
my panel display total p10 module is 25 used.
i trying 1st arduino uno - connected 13 p10 module.
2 nd arduino uno - connected 13 p10 module.

one hardware serial port from pc and two arduino uno board connected.

Your description is very unclear.

If you want to communicate with the PC using Serial then create SoftwareSerial port on the Uno for communication with the other Uno.

Have a look at the examples in Serial Input Basics - simple reliable ways to receive data. There is also a parse example to illustrate how to extract numbers from the received text.

The technique in the 3rd example will be the most reliable.

You can send data in a compatible format with code like this

Serial.print('<'); // start marker
Serial.print(value1);
Serial.print(','); // comma separator
Serial.print(value2);
Serial.println('>'); // end marker

...R