Help with 1.2" 8x8 Matrix

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Durlov
 
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Joined: Fri Sep 19, 2014 9:07 pm

Help with 1.2" 8x8 Matrix

Post by Durlov »

Hello,

New to Arduino. I'm trying to learn how to control the display on the LED. I followed the instructions on https://learn.adafruit.com/adafruit-led ... 8x8-matrix and got it to start displaying a bunch of displays, but how to I create my own display? For example, how can I make the led matrix spell: M - delay (10 secs) - U - delay (10 secs) - J - delay (10 secs) - I - delay (10 secs) - B - delay (10 secs)? Some direction to tutorials would be helpful. I don't see any video tutorials online, so if I learn this properly, I'll look into making some myself.

Thanks,

Syed

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SeiRruf
 
Posts: 82
Joined: Thu Sep 04, 2014 3:07 am

Re: Help with 1.2" 8x8 Matrix

Post by SeiRruf »

Hello Durlov, and welcome to the Adafruit forums!

LED Matrix are the best, I have a few, but haven't been able to get any of the ones from Adafruit recently, so I am not 100% familiar with the code structure for them. However, I spent some time to look it over and not surprisingly, it was pretty simple. Most Adafruit libraries are!

I wrote some sample code for you that technically *should* do what you described. I kept it well commented so you can follow along and change it as you'd desire. It's yours to keep, modify & learn from. Just copy/paste it into a new sketch and Upload!

Code: Select all

#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"

Adafruit_8x8matrix matrix = Adafruit_8x8matrix();

char myMsg[] = "MUJIB"; //YOU CHANGE THIS IF DESIRED

void setup ()
{
  //start Serial for debugging
  Serial.begin ( 9600 );
  Serial.println ( "8x8 Matrix Text! Sample code by SeiRruf (untested)" );
  
  //address the display we're writing to
  matrix.begin ( 0x70 );
  
  //text size, probably should be left at 1, not sure (I don't have this display)
  //matrix.setTextSize(1);
  
  //i am not 100% sure what this does, but I think it makes it so the text does or doesn't repeat at the edges
  matrix.setTextWrap ( false );
  
  //let the matrix know we're lighting up the following letters
  matrix.setTextColor ( LED_ON );
  
  //if you want to rotate the letter, be my guest
  matrix.setRotation ( 0 ); // 0 = right side up
  
  //position start pixel to x,y -> 0,0;
  matrix.setCursor ( 0, 0 );
}

void loop ()
{ 
  for ( int i = 0; i < sizeof(myMsg) - 1; i++ ) { //for each character in the message given,
    matrix.clear ();                              //clear display for next coming letter
    matrix.print ( myMsg[i] );                    //write next letter to memory
    Serial.println ( myMsg[i] );                  //debug, send the message to console as well
    matrix.writeDisplay ();                       //push memory to LED matrix
    delay ( 10000 );                              //10 seconds delay
  }
}
Last edited by SeiRruf on Sat Sep 20, 2014 6:25 pm, edited 1 time in total.

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Durlov
 
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Re: Help with 1.2" 8x8 Matrix

Post by Durlov »

Thanks, SeiRruf. Your code is very well commented! I'll try it out and let you know how it goes.

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Durlov
 
Posts: 3
Joined: Fri Sep 19, 2014 9:07 pm

Re: Help with 1.2" 8x8 Matrix

Post by Durlov »

Hey SeiRruf, the code doesn't seem to be working. I just copy pasted what you put on the website into a new sketch. The LED matrix just went blank.

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SeiRruf
 
Posts: 82
Joined: Thu Sep 04, 2014 3:07 am

Re: Help with 1.2" 8x8 Matrix

Post by SeiRruf »

Durlov wrote:Hey SeiRruf, the code doesn't seem to be working. I just copy pasted what you put on the website into a new sketch. The LED matrix just went blank.
I went ahead and updated the code in my original post. Try it again?
It is using all the same variables as the 8x8 matrix example included with the library, but I do not have an LED matrix to test it with.

I added Serial to it, so after uploading the new code, check your arduino's console on BAUD 9600, it should display the letters as they "should" be showing on the matrix.
I am curious with this too, as I will be getting a matrix within a month, and am trying to learn about these backpacked ones as well.

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