Scrolling Message on 8x8 LED Matrix

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DSCF9288.JPG
DSCF9288.JPG1280×1026 176 KB

This may not look like 12 hours of work, but I reckon I spent appx 4 hours writing a little program to design the font, about 2 hours making the font, probably around an hour building the patchboard around the matrix, and maybe 6 hours getting the message to scroll smoothly. If anyone wants the font designer program (Windows PC only), PM me and I can send you an installer package.

I find that, particularly with the lowercase letters, there's too much space bwtween them, so the next plan is to make the font "proportional."


https://www.youtube.com/watch?v=VGeIhV0yU5A
2

Damn…

Gosh darnit, it is always good to see you, Mr. BOA.

 

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CODE

CTC! Dawg! I’ve been watching your 3D printer, and stuff. Loved teh bike project, too! Where teh heck do you find the time?!?!

Any clues how I get the code to format correctly? Used to just put HTML CODE tags, but that doesn’t seem to work any more…

4

Sorry OB. I know you would rather I hadn’t posted this.

/* ****************************************************************************

LEDmatrix.ino
I made this. Freely donated to the community. I take no responsibility for

harm caused by this program, but will happily accept credit for any good that

comes of it.

*******************************************************************************/


#include <avr/pgmspace.h>


// Pin configuration for Arduino Uno

const int runLamp = 13;

const int R8 = 12; // rows

const int R7 = 11;

const int R6 = 10;

const int R5 =  9;

const int R4 =  8;

const int R3 =  7;

const int R2 =  6;

const int R1 =  5;


const int C8 =  4; // columns

const int C7 =  3;

const int C6 =  2;

const int C5 = A5;

const int C4 = A4;

const int C3 = A3;

const int C2 = A2;

const int C1 = A1;


// Software Constants

const int rowPin[8] = {R1,R2,R3,R4,R5,R6,R7,R8};

const int colPin[8] = {C1,C2,C3,C4,C5,C6,C7,C8};


// Font

prog_uchar font[760] PROGMEM = {

0,0,0,0,0,0,0,0,12,12,12,12,0,12,12,0,20,20,20,0,0,0,0,0,76,254,76,76,254,76,76,0,

60,86,22,60,80,86,60,0,102,110,12,24,48,118,102,0,28,38,54,12,86,38,92,0,8,8,8,0,0,0,0,0,

8,4,6,6,6,6,4,8,16,32,96,96,96,96,32,16,8,42,28,8,28,42,8,0,0,8,8,62,8,8,0,0,

0,0,0,0,0,12,12,2,0,0,0,62,0,0,0,0,0,0,0,0,0,12,12,0,32,32,16,8,4,2,2,0,

28,38,54,46,38,38,28,0,24,28,28,24,24,24,24,0,28,38,32,24,4,6,62,0,28,38,32,24,32,38,28,0,

44,44,38,38,62,32,32,0,62,6,30,32,32,38,28,0,28,38,6,30,38,38,28,0,62,32,16,8,8,4,4,0,28,38,38,28,38,38,28,0,

28,38,38,60,32,32,28,0,0,0,12,12,0,12,12,0,0,0,12,12,0,12,12,2,32,16,8,4,8,16,32,0,

0,0,62,0,62,0,0,0,4,8,16,32,16,8,4,0,12,18,16,12,0,12,12,0,62,65,89,85,57,65,62,0,

60,70,70,126,70,70,70,0,62,70,70,62,70,70,62,0,60,70,6,6,6,70,60,0,30,38,70,70,70,38,30,0,

126,6,6,30,6,6,126,0,126,6,6,62,6,6,6,0,60,70,6,6,118,70,60,0,70,70,70,126,70,70,70,0,

126,24,24,24,24,24,126,0,126,24,24,24,24,8,6,0,70,38,22,14,22,38,70,0,6,6,6,6,6,6,126,0,

70,110,86,70,70,70,70,0,70,78,86,86,102,70,70,0,60,70,70,70,70,70,60,0,62,70,70,62,6,6,6,0,

60,70,70,70,86,38,92,0,62,70,70,62,70,70,70,0,60,70,6,60,64,70,60,0,126,24,24,24,24,24,24,0,

70,70,70,70,70,70,60,0,70,70,70,44,44,24,24,0,70,70,70,70,70,86,44,0,70,46,44,24,52,116,98,0,

70,70,44,24,24,24,24,0,126,96,48,24,12,6,126,0,60,12,12,12,12,12,60,0,2,2,4,8,16,32,32,0,

60,48,48,48,48,48,60,0,8,20,34,0,0,0,0,0,0,0,0,0,0,0,0,127,4,8,0,0,0,0,0,0,

0,0,12,16,28,18,28,0,2,2,2,14,18,18,14,0,0,0,0,12,2,2,12,0,16,16,16,28,18,18,28,0,

0,0,12,18,30,2,12,0,0,0,24,4,14,4,4,4,0,0,0,28,18,28,16,12,2,2,2,14,18,18,18,0,

0,0,4,0,4,4,4,0,0,0,4,0,4,4,4,2,2,2,2,10,6,10,10,0,2,2,2,2,2,2,4,0,

0,0,0,22,42,34,34,0,0,0,0,14,18,18,18,0,0,0,0,12,18,18,12,0,0,0,0,14,18,14,2,2,

0,0,0,28,18,28,16,16,0,0,0,26,6,2,2,0,0,0,28,2,12,16,14,0,0,4,4,14,4,4,24,0,

0,0,0,18,18,18,28,0,0,0,0,34,34,20,8,0,0,0,0,34,34,42,20,0,0,0,0,18,12,12,18,0,

0,0,0,18,18,28,16,12,0,0,0,30,8,4,30,0,16,8,8,4,8,8,16,0,8,8,8,8,8,8,8,0,

8,16,16,32,16,16,8,0,0,76,50,0,0,0,0,0

};


// Global Variables

boolean frame[8][8];

String msg = String(" BaseOverApex says “LETSMAKEROBOTS” ");

boolean runLampToggle = true;

int n; // index of the character within the string

int row; // index of a particular row of the font character

int col; // index of a particular column of the font character

int ch1, ch2; // ASCII value of current character - 32

word row16[8]; // all bis required for 2 charachers


void setup() {

for (int i=0;i<8;i++) {

pinMode(rowPin[i], OUTPUT);

pinMode(colPin[i], OUTPUT);

digitalWrite(colPin[i], HIGH);

digitalWrite(rowPin[i], LOW);

}

pinMode(runLamp, OUTPUT);

} // setup


void loop() {

for (n=0; n<msg.length()-1; n++) { // for each character in the string

digitalWrite(runLamp, runLampToggle);

runLampToggle = !runLampToggle;

// get current and next characters

ch1 = msg.charAt(n) - 32;

ch2 = msg.charAt(n + 1) - 32;

// compile array of 16-bit bytes corresponding to the bit patterns

// the current char and the next char

for (row=0; row<8; row++) {

row16[row] = pgm_read_byte_near(font + (ch1  8) + row)

+ (pgm_read_byte_near(font + (ch2  8) + row) << 8);

}

for (int scroll=0; scroll<8; scroll++) {

// for each of 8 columns, compile a byte representing the bit pattern

// for the column and transfer it into the frame buffer

for (col=0; col<8; col++) {

word mask = 1 << (col + scroll);

byte colByte = 0;

for (int row=0; row<8; row++) {

colByte += (1<<row) * (((row16[row] & mask) == 0) ? 0:1);

}

writeCol(col, colByte);

} // for col

// display it

for (int z=0; z<3; z++) {

refresh();

delay(10);

}

} // for scroll

} // for n

} // loop


void writeCol (int col, byte data) {

byte mask = 1;

for (int row=0; row<8; row++) {

frame[col][row] = data & mask; // sel col bit on

mask = mask << 1;

}

} // writeCol


void refresh() {

for (int x=0; x<8; x++) {

digitalWrite(colPin[x],true); // column off

for (int y=0; y<8; y++) {

digitalWrite(rowPin[y],frame[x][y]); // row bit on

}

digitalWrite(colPin[x],false); // column on

delay(2);

digitalWrite(colPin[x],true); // column off

}

} // refresh
5

The code

Oh, the Arduino sketch…

See below.

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like it!

like your project! good stuff.

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Cool!

Hi BaseOverApex,

That’s a cool project! no surprises it took so many hours just to display scrolling text considering i too did something similar a few days ago- https://www.robotshop.com/letsmakerobots/node/38114 . I instead used four shift registers to make a 8X24 LED matrix (the linked post is a little old as now i have further expanded it to 24 coloumns), one for the 8 rows and three for the 24 coloums.

I too had the same problem of the spaces between the charaters so i fixed the first byte of each character a ‘blank’ space and used the commonly used 7X5 LCD font so each char in my code is 7X6 . Some characters and symbols like I, 1, !, (, ), .  are less than 5 spaces long so they look a little strange. Here is my code-    https://www.dropbox.com/sh/xtlttkzplrpl3tn/nwHMHb2XqV

video of the code running on a arduino- http://www.youtube.com/watch?v=bhTULHJGAZA

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Haven’t been around in a while

Forgot about that! Stone me, what alovely font. I think I wrote a font editor for that…

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Great job! check % symbol

Great job!

Your % symbol is inverted. It should be …102,118,48,24,12,110,102,0… instead of …102,110,12,24,48,118,102,0…

:wink:

Ale