Scrolling Text LED matrix P10 (1R) with Arduino Mega 2560

Greetings friends,

I would like this forum esmpezar waiting aluno help you.

My problem is I can not get moving text in the matrix led P10 (1R), only one bar illuminated LED displays, I'm using Arduino Mega 2560, I read somewhere that the DMD library is made for Arduino Uno, I wonder if atravezado any of you you have this problem and if a fixed, how did ?,

Enclosed is my programming example:


#include <Arial14.h>
#include <Arial_black_16.h>
#include <Arial_Black_16_ISO_8859_1.h>
#include <DMD.h>
#include <SystemFont5x7.h>
#include <SPI.h>
#include "TimerOne.h"
#include <SoftwareSerial.h> 
/* you can remove the fonts if unused */
#define DISPLAYS_ACROSS 1
#define DISPLAYS_DOWN 1
DMD dmd( DISPLAYS_ACROSS , DISPLAYS_DOWN );

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

void setup(){
Serial.begin(9600);
Timer1.initialize( 2000 );           
Timer1.attachInterrupt( ScanDMD );  
dmd.clearScreen( true );            
}

String textToScroll="Hello, this will be displayed on the DMD";

void drawText( String dispString ){
dmd.clearScreen( true );
dmd.selectFont( Arial_Black_16 );
char newString[256];
int sLength = dispString.length();
dispString.toCharArray( newString, sLength+1 );
dmd.drawMarquee( newString , sLength , ( 32*DISPLAYS_ACROSS )-1 ,0);
long start=millis();
long timer=start;
long timer2=start;
boolean ret=false;
while( !ret ){
if ( ( timer+20 ) < millis() ) {
  ret=dmd.stepMarquee( -1 , 0 );
  timer=millis();
}
}
}

void loop(){
Serial.println(textToScroll);
drawText(textToScroll);
}

Also how you connect the array with the Arduino pins:

This is my result:

The library I use this at this link:

angelvinny,

I asked you to read the "Read This" post before you started this topic. I can see that you have not done that. Why do you refuse my simple and polite request?

Paul

Friend Paul,

I am not rude not understand what you mean, "Read this" post before starting this topic,

I do not want to be rude just want some input to my problem,

Tell me where I read it and I will gladly

It is a sticky post at the top of every forum here titled "How to use this forum - please read.". But i can see that you have now read it and edited your post above, so thankyou.

I think the moderators should change the name of that post to "Top Secret: Do not read this post". I think more new members would read it then :wink:

Your schematic is not good. You copied it from.somewhere and so it does not show how you have connected your Arduino to the display.

Your sketch expects you to connect the Arduino's SPI outputs. These are different pins on the Mega compared to the Uno. Which pins have you used? Have you researched which pins are the SPI pons on Mega?

I do not think your display is incompatible with Mega.

Hi Paul,

I attached the connection of the 16-pin connector, as I read are the pins of Arduino Uno, according to the SPI library that is included in the DMD library for Arduino Mega2560 is pin 51, but did not work, I hope some input to get me out of this predicament :confused:

The matrix used is this: 32x16 Red Dot Matrix Display | Freetronics

Thank you...

Hi, i never used a Mega but according to this page I think you should be using pins 51, 52:

Digital pin 51 (MOSI) --> Display Pin 12
Digital pin 52 (SCK) --> Display Pin 8

Greetings PaulRB,

If I have reviewed, I made the change you indicate me and it did not work, I still have the same problem, also I have now changed Arduino and I'm working with Arduino Uno and does not work, is not whether lack something in addition to what I have indicated schemes, or the program, if anyone has had the same problem I hope to fix guide know, many people have seen this post and only one has provided help,

Friends someone can see where this error.

:o

Have you tried one of the Freetronics demo sketches exactly as published? Is your Uno connected exactly as shown in the diagram you posted above? What power supply are you using?

Your picture shows a very large breadboard with many components visible. Are you certain these other components are not interfering with your circuit?

Yes, I have connected everything according to what is stated and tried with these programs as an example but does not work, I'm coming to the conclusion that the matrix may be the problem, because I have already implemented Arduino Uno, with examples of this page and with the right connections indicated and does not respond as I would like,

I used an external source of 5V to 10Amp, enough for this matrix and I also tested directly with Arduino 5V delivery nor works.

I also thought that these other components of another project on the board interfere in what I do, and I reduced to a proto exclusive matrix board for Arduino:

Could this be the problem matrix?

:o :o :confused:

Perhaps yes. If you purchased the matrix from Freetronics and you are using their example sketch and it is not working, have you asked for help on the Freetronics forum?

If I started a new post like this freetronic forum, I hope to have better luck here:

http://forum.freetronics.com/viewtopic.php?f=26&t=6396

Thanks PaulRB

:grinning:

Hello friends,

A run Arduino Uno, and it was actually the matrix problem was defective, I now return to testing with Arduino Mega 2560 that was the bottom line.

Suddenly I attached a video of what was done ..

:grin: :sunglasses: