All the resources for this project can be found here: http://randomnerdtutorials.com/android-app-that-sends-a-message-to-your-arduino

send_message

/*

 Send a message to your arduino via bluetooth
 All the resurces for this project can be found at:
 
 http://randomnerdtutorials.com/android-app-that-sends-a-message-to-your-arduino

 Modified by Rui Santos, Based on Marc Alexander example.

 USAGE NOTES
 -----------
 - Download the DMD library here: https://github.com/freetronics/DMD
 - Place the DMD library folder into the "arduino/libraries/" folder of your Arduino installation.
 - Get the TimerOne library from here: http://code.google.com/p/arduino-timerone/downloads/list
   or download the local copy from the DMD library page (which may be older but was used for this creation)
   and place the TimerOne library folder into the "arduino/libraries/" folder of your Arduino installation.
 - Restart the IDE.

*/

#include <SPI.h>        //SPI.h must be included as DMD is written by SPI (the IDE complains otherwise)
#include <DMD.h>        //
#include <TimerOne.h>   //
#include "SystemFont5x7.h"
#include "Arial_black_16.h"

//Fire up the DMD library as dmd
#define DISPLAYS_ACROSS 1
#define DISPLAYS_DOWN 1
DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN);
//number max of characters in your message
#define max_char 100
char message[max_char];    // stores you message
char r_char;               // reads each character
byte index = 0;            // defines the position into your array
int i;            

/*--------------------------------------------------------------------------------------
  Interrupt handler for Timer1 (TimerOne) driven DMD refresh scanning, this gets
  called at the period set in Timer1.initialize();
--------------------------------------------------------------------------------------*/
void ScanDMD()
{ 
  dmd.scanDisplayBySPI();
}

void setup(void)
{

   //initialize TimerOne's interrupt/CPU usage used to scan and refresh the display
   Timer1.initialize( 5000 );           //period in microseconds to call ScanDMD. Anything longer than 5000 (5ms) and you can see flicker.
   Timer1.attachInterrupt( ScanDMD );   //attach the Timer1 interrupt to ScanDMD which goes to dmd.scanDisplayBySPI()

   //clear/init the DMD pixels held in RAM
   dmd.clearScreen( true );   //true is normal (all pixels off), false is negative (all pixels on)
   Serial.begin(9600);
}
void loop(void)
{
   //check if serial is avaible an before reading a new message delete's the old message
   if(Serial.available()){       
        for(i=0; i<99; i++){
            message[i] = '\0';
        } 
        //resests the index        
        index=0;
    }
    //while is reading the message 
    while(Serial.available() > 0){
       //the message can have up to 100 characters 
       if(index < (max_char-1)) 
       {         
           r_char = Serial.read();      // Reads a character
           message[index] = r_char;     // Stores the character in message array
           index++;                     // Increment position
           message[index] = '\0';       // Delete the last position
       }
   }
   //prepares the display to print our message
   dmd.clearScreen( true );
   dmd.selectFont(Arial_Black_16);
   //displays the message
   dmd.drawMarquee(message, max_char,(32*DISPLAYS_ACROSS)-1 ,0);
   long start=millis();
   long timer=start;
   boolean ret=false;
   while(!ret){
     if ((timer+30) < millis()) {
       ret=dmd.stepMarquee(-1,0);
       timer=millis();
     }
   }
}

hello
what software do you use to create a font???

how change code if ı use 16x96 dmd .And how can ı animations 16x96 with arduino bluetooth send message can you send me code please

Pls, my display board is working fine but the display can only show messages with not more than 70 characters, i need help please. The code i used is same as this one