Matrix display, ''more'' than matrix size to show, hidden characters sort of?

Projects Programming
1

I tried to describe my problem in subject, but so, i managed to buil code & of course circuit for 8x8 matrix, no big deal there (thought it was bothersome without using libraries.....) but now then, i'd like to use bigger strings of text. if i increase size of array, sure, but counter won't count up enought to display changes. If i increase value of that counter, columns array overshoots then. of course i could just make bigger display but that seems pointless if display string takes only half....and that only shifsts problem further, soon i must make again bigger display, i know it's possible to make long chains of text but can't figure it out. So, help & advice greatly appreciated! screen shows just an arrow that slides along the display, if that makes any difference. And, i use 74595's to drive display along with darlington arrays
i don't have any max's ic's.

int dataPin = 2;        //IC 14       //Define which pins will be used for the Shift Register control
int latchPin = 3;       //IC 12
int clockPin = 4;       //IC 11
//OE-GND
//MR-VCC
int const t = 2000;

byte x [8] =
{
  B00001000,
  B00001100,
  B00001110,
  B01111111,
  B01111111,
  B00001110,
  B00001100,
  B00001000,
};

byte columns [8] =
{
  B00000001,
  B00000010,
  B00000100,
  B00001000,
  B00010000,
  B00100000,
  B01000000,
  B10000000,
};


void setup()
{
  DDRD = DDRD | B00011100;                                  //set pins as output

}

void loop()
{
  int a, hold, shift;
  for ( shift = 0 ; shift < 7 ; shift++ )                   //amount to shift
  {
    for (hold = 0; hold < 25; hold++)                       //time for shifting
    {
      for (a = 0; a < 8; a++)                               //how many arrays to load?
      {
        PORTD = B00000000;                                  //turn latch low
        shiftOut(dataPin, clockPin, MSBFIRST, columns[a]);          //Send the data #2        (what columns to power)
        shiftOut(dataPin, clockPin, LSBFIRST, x[a]>>shift);          //Send the data #1       ( what data to draw)      
        PORTD = B00001000;                                  //turn latch on->show screen
        delayMicroseconds (t);
      }
    }
  }
}
2

if i increase size of array, sure, but counter won't count up enought to display changes.

What counter won't count up high enough?

  int a, hold, shift;
  for ( shift = 0 ; shift < 7 ; shift++ )                   //amount to shift
  {
    for (hold = 0; hold < 25; hold++)                       //time for shifting
    {
      for (a = 0; a < 8; a++)

This is C++, not C.

  for (int shift = 0 ; shift < 7 ; shift++ )                   //amount to shift
  {
    for (int hold = 0; hold < 25; hold++)                       //time for shifting
    {
      for (int a = 0; a < 8; a++)
3

I mean by ''counter'' when a increments, it causes screen to mess up as there is same int for for both columns and rows, so if i place more stuff (more letters) for array [x] it causes that column section to mess up, as there are no more columns than 8

byte x [8] =
{
  B00001000,
  B00001100,
  B00001110,
  B01111111,
  B01111111,
  B00001110,
  B00001100,
  B00001000,
};

for (a = 0; a < 8; a++)
shiftOut(dataPin, clockPin, MSBFIRST, columns[a]);
        shiftOut(dataPin, clockPin, LSBFIRST, x[a]>>shift);

about c++ and c it worked so i didn't think it would effect, thanks for pointing that out! my coding-eye isn't that fixed enough yet to spot difference between c++ and c (no programming education here except google....)

4

I could control cathode shifter by its own, but for now i'd like to control them in series, daisy chained, if that would give you guys any insight?

5

just mentioning here that got this solved! and shift registers in daisy chained