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Topic: display a single letter on 8x8 dot matrix (Read 4494 times) previous topic - next topic

mr_hacker90

hi. i want to ask. at which part of this program i need to amend so that the dot matrix display is not scrolling from right to left. i just want the display of the dot matrix stay still.. basically i'm newbie in arduino. and this code i get it from arduino playground. i want to display the dot matrix for my younger sister as her present during her birthday. i found that this code is quite difficult to understand as i'm newbie with arduino. even with microcontroller. so, i guess i want to start with a simple code first, which display a single letter from  the dot matrix. rather than i just copied and paste the code, it is better for me to make a simple project at least i understand rather than i make a nice project but i don't understand & the code itself just copy and paste. hope u guys can help me... thank you. with all, regards...

Code: [Select]

/*
* Show messages on an 8x8 led matrix,
* scrolling from right to left.
*
* Uses FrequencyTimer2 library to
* constantly run an interrupt routine
* at a specified frequency. This
* refreshes the display without the
* main loop having to do anything.
*
*/

#include <FrequencyTimer2.h>

#define SPACE { \
    {0, 0, 0, 0, 0, 0, 0, 0},  \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0}, \
    {0, 0, 0, 0, 0, 0, 0, 0} \
}

#define H { \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 1, 1, 1, 1, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}  \
}

#define E  { \
    {0, 1, 1, 1, 1, 1, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 1, 1, 1, 1, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 1, 1, 1, 1, 1, 0}  \
}

#define L { \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 0, 0}, \
    {0, 1, 1, 1, 1, 1, 1, 0}  \
}

#define O { \
    {0, 0, 0, 1, 1, 0, 0, 0}, \
    {0, 0, 1, 0, 0, 1, 0, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 1, 0, 0, 0, 0, 1, 0}, \
    {0, 0, 1, 0, 0, 1, 0, 0}, \
    {0, 0, 0, 1, 1, 0, 0, 0}  \
}

byte col = 0;
byte leds[8][8];

// pin[xx] on led matrix connected to nn on Arduino (-1 is dummy to make array start at pos 1)
int pins[17]= {-1, 5, 4, 3, 2, 14, 15, 16, 17, 13, 12, 11, 10, 9, 8, 7, 6};

// col[xx] of leds = pin yy on led matrix
int cols[8] = {pins[13], pins[3], pins[4], pins[10], pins[06], pins[11], pins[15], pins[16]};

// row[xx] of leds = pin yy on led matrix
int rows[8] = {pins[9], pins[14], pins[8], pins[12], pins[1], pins[7], pins[2], pins[5]};

const int numPatterns = 6;
byte patterns[numPatterns][8][8] = {
  H,E,L,L,O,SPACE
};

int pattern = 0;

void setup() {
  // sets the pins as output
  for (int i = 1; i <= 16; i++) {
    pinMode(pins[i], OUTPUT);
  }

  // set up cols and rows
  for (int i = 1; i <= 8; i++) {
    digitalWrite(cols[i - 1], LOW);
  }

  for (int i = 1; i <= 8; i++) {
    digitalWrite(rows[i - 1], LOW);
  }

  clearLeds();

  // Turn off toggling of pin 11
  FrequencyTimer2::disable();
  // Set refresh rate (interrupt timeout period)
  FrequencyTimer2::setPeriod(2000);
  // Set interrupt routine to be called
  FrequencyTimer2::setOnOverflow(display);

  setPattern(pattern);
}

void loop() {
    pattern = ++pattern % numPatterns;
    slidePattern(pattern, 60);
}

void clearLeds() {
  // Clear display array
  for (int i = 0; i < 8; i++) {
    for (int j = 0; j < 8; j++) {
      leds[i][j] = 0;
    }
  }
}

void setPattern(int pattern) {
  for (int i = 0; i < 8; i++) {
    for (int j = 0; j < 8; j++) {
      leds[i][j] = patterns[pattern][i][j];
    }
  }
}

void slidePattern(int pattern, int del) {
  for (int l = 0; l < 8; l++) {
    for (int i = 0; i < 7; i++) {
      for (int j = 0; j < 8; j++) {
        leds[j][i] = leds[j][i+1];
      }
    }
    for (int j = 0; j < 8; j++) {
      leds[j][7] = patterns[pattern][j][0 + l];
    }
    delay(del);
  }
}

// Interrupt routine
void display() {
  digitalWrite(cols[col], LOW);  // Turn whole previous column off
  col++;
  if (col == 8) {
    col = 0;
  }
  for (int row = 0; row < 8; row++) {
    if (leds[col][7 - row] == 1) {
      digitalWrite(rows[row], LOW);  // Turn on this led
    }
    else {
      digitalWrite(rows[row], HIGH); // Turn off this led
    }
  }
  digitalWrite(cols[col], HIGH); // Turn whole column on at once (for equal lighting times)
}

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