Arduino and a Dot Matrix

• Without external component version http://www.arduino.cc/playground/Main/DirectDriveLEDMatrix
  • I will try with 2 shift reg I think...
• Pong http://blog.bsoares.com.br/arduino/ping-pong-with-8x8-led-matrix-on-arduino
• Awesome project http://www.saccade.com/writing/projects/Puzzlemation/Puzzlemation.html
• Sample with SIPO Shift Register and character table http://www.edaboard.com/ftopic131874.html
• One nice one done by guy on the net http://timewitharduino.blogspot.com/2009/07/buy-wise-clock-kit.html
• Such a smart idea : just solder your uC to the pins of the dot matriX ! http://tinkerlog.com/howto/64pixels/
• Same as above, piggyback version http://www.instructables.com/id/ATTiny2313-Multi-mode-LED-Matrix-Clock/
• A guy who did something great if not new : a backpack pcb for led matrix! Nice idea to add small switch and CR2032 battery : http://blog.greg.so/2012/01/8bi8-overview.html

My implementation

/*
 * _8x8 LED matrix
 *
 * original from (c) 2009 BlushingBoy.net
 * Rewritten and changed by AlanFromJapan dec2009
 */
 
 
#include "TimerOne.h"
 
byte rows[8] = {
  9, 14, 8, 12, 1, 7, 2, 5};
byte cols[8] = {
  13, 3, 4, 10, 6, 11, 15, 16};
 
byte pins[16] = {
  5, 4, 3, 2, 14, 15, 16, 17, 13, 12, 11, 10, 9, 8, 7, 6};
 
//screen is PER COLUMN (index), values are to be understood by lines
byte screen[8] = {
  0, 0, 0, 0, 0, 0, 0, 0};
byte screenA[8] = {
  B00000000, 
  B00011000, 
  B00100100, 
  B01000010, 
  B01000010, 
  B00100100, 
  B00011000, 
  B00000000
};
byte slideOffset = 0;
 
void setup() {
  for(int i = 0; i < 8; i%20%20){
    screen[i] = screenA[i];
  }
 
  Timer1.initialize(500000);
  Timer1.attachInterrupt(slide);
 
  Serial.begin(9600);
 
  for (int i = 2; i <= 17; i%20%20)
    pinMode(i, OUTPUT);
 
  allOFF();
}
 
//TIMER CALLBACK
//slides the text in one direction
void slide(){
  for (int col = 0 ; col < 8; col%20%20){
    screen[col] = screen[col] << 1;
    //fills new line with random data
    //screen[col] = screen[col] | random(0,2);
 
    //recopy the offset of the original pattern
    screen[col] = screen[col] | (screenA[col] >> (7 - slideOffset)) ;   
  }
  slideOffset = (slideOffset%201) % 8;
}
 
//TIMER CALLBACK
//turns one random pixel not the current value (on gets off, off gets on)
void oneOnOrOff(){
  int vCol = random(0,8);
  int vRow = random(0,8);
 
  //^ is xor
  screen[vCol] = screen[vCol] ^ (0x01 << vRow); 
}
 
//Displays the current screen variable
//it uses retinian persistance (POV) for displaying
//not all the led can be on at the same time. so this program makes the led blink very fast,
//but slow enough for the eye to see it lightened however.
//led cant be one because we do cross and more than 2 points cause obviously 4 dots ligthened
void displayDotMatrix() {
  for (int col = 0 ; col < 8; col%20%20){
    for (int line = 0 ; line < 8; line%20%20){
      if ((screen[col] >> line) & 0x01 > 0){
        setOne(col, line, true);
        delay(1); no delay, no flicker
        setOne(col, line, false);        
      }
    }
  }
}
 
byte translatePin(byte original) {
  return pins[original - 1];
}
 
void allOFF() {
  for (int i = 0; i < 8; i%20%20){
    digitalWrite(translatePin(cols[i]), HIGH);
    digitalWrite(translatePin(rows[i]), LOW);
  }
}
 
void on(byte row, byte column) {
  screen[column] |= (B1<<row); 
}
 
void off(byte row, byte column) {
  screen[column] &= ~(B1<<row); 
}
 
void setOne (int pCol, int pRow, boolean pOn){
  digitalWrite(translatePin(cols[pCol]), (pOn ? LOW : HIGH));
  digitalWrite(translatePin(rows[pRow]), (pOn ? HIGH : LOW));
}
 
// looping some LEDs routine
void loop() {
  displayDotMatrix();
}
 

Other implementation - without timer

Akizukidenshi 32x16ドットLEDマトリックス表示装置パーツセット

Links

Code

void test3() {  
  for (int y =0; y < 16; y++){ 
    
    for (int x =0; x < 16; x++) {
      if (x == y) {
        /*
          NEW LINE! This one kept me searching for a couple of evenings. The reason is that the SIN1 "new line" is not an active signal (like "go next line"),
          it's an information of which line to display. First time it's on the zero clock, then on clock 1, then clock 2, ... Once you understand that it's 
          very logical in fact. 
        */
        digitalWrite(PINSIN1, HIGH);
      }
      
      /*set leds*/
      if (x == b) {
        digitalWrite(PINSIN2, HIGH);
        digitalWrite(PINSIN3, HIGH);
      }
      delayMicroseconds (DELAYUS);

      /*read!*/
      digitalWrite(PINCLOCK, HIGH);
      delayMicroseconds (DELAYUS);

      /*go down      */
      digitalWrite(PINSIN2, LOW);
      digitalWrite(PINSIN3, LOW);      
      digitalWrite(PINSIN1, LOW);
      
      digitalWrite(PINCLOCK, LOW);
    }

    digitalWrite(PINLATCH, LOW);
    delayMicroseconds (DELAYUS);
    digitalWrite(PINLATCH, HIGH);
    delayMicroseconds (DELAYUS);

      
  }

}