64x32 ledpanel driver

ledpanel.ino

// PINS

// OE  A
// -   B
// -   -
// -   CLK
// -   SCLK
// -   -
// -   R
// -   -

#include <TimerOne.h>
#include <SPI.h>

const int PIN_OE = 13; 
const int PIN_A = 12;
const int PIN_B = 11;
const int PIN_SCLK = 9;

// const int PIN_CLK = 5; 
// const int PIN_R = 6;

const int PANELWIDTH = 64;
const int PANELHEIGHT = 16;
const int PANELPLANES = 4;
const int PANELPLANESIZE = 8;

int frame = 0;
int scan_row = 0;

char *pixels = 
//0       1       2       3       4       5       6       7  
//0123456701234567012345670123456701234567012345670123456701234567
 "................................................................" // 0
 ".1111...1111..111..1111..1...1.1................................"
 ".1...1.1.....1...1.1...1.1...1.1................................"
 ".1111..1111..11111.1...1..111..1................................"
 ".1...1.1.....1...1.1...1...1...................................." // 4
 ".1...1..1111.1...1.1111....1...1................................"
 "................................................................"
 "................................................................"
 "................................................................" // 8
 "................................................................"
 "................................................................"
 "................................................................"
 "................................................................" // 12 
 "................................................................"
 "................................................................"
 "................................................................";
 
unsigned short pixelmap[64*16/4];
int pixelmap_size;
unsigned short pixelmapoffset[4];

void select_row(int r) {
  digitalWrite(PIN_A, (r & 1) == 1);
  digitalWrite(PIN_B, (r & 2) == 2);
}

/*
static inline void latch_pixel(int r) {
  digitalWrite(PIN_CLK, 0);
  digitalWrite(PIN_R, r > 0 ? LOW : HIGH);
  digitalWrite(PIN_CLK, 1);
  digitalWrite(PIN_CLK, 0);
}
*/

void scan_display() {
  digitalWrite(PIN_SCLK, 0);
  for(int i=0; i<pixelmap_size; i++) {
    int o = pixelmap[i] + pixelmapoffset[scan_row];
    int bo = 0; 
    for(int b=7; b>=0; b--) {
      // one segment
      char ch = pixels[o + b];
      if (ch != '1') bo |= (1 << b);
    }
    SPI.transfer(bo);
  }
  digitalWrite(PIN_OE, 0);
  digitalWrite(PIN_SCLK, 1);
  select_row(scan_row);
  digitalWrite(PIN_OE, 1);
  delayMicroseconds(1);
}

void callback()
{
  scan_display();
  scan_row ++;
  if (scan_row >= 4) {
    scan_row = 0;
    frame ++;
    frame %= 64*16/4;
  }
}

void setup() {
  // put your setup code here, to run once:
  pinMode(PIN_A, OUTPUT); 
  pinMode(PIN_B, OUTPUT);
  pinMode(PIN_OE, OUTPUT);
  pinMode(PIN_SCLK, OUTPUT);
  // pinMode(PIN_CLK, OUTPUT); 
  // pinMode(PIN_R, OUTPUT);
  
  SPI.begin();
  SPI.setBitOrder(MSBFIRST);
  SPI.setDataMode(SPI_MODE0);	// CPOL=0, CPHA=0
#ifdef __AVR__
  SPI.setClockDivider(SPI_CLOCK_DIV4); // 4MHz clock
#else
  SPI.setClockDivider(20); // 4.2MHz on Due
#endif

  int oo = 0;
  for(int c=(PANELWIDTH >> 3) - 1; c>=0; c--) {
    int bx = 8 * c;
    for(int r=0; r<4; r++) {
      int by = (r * 4) + 3;
      int o = (by * PANELWIDTH) + bx;
      pixelmap[oo++] = o;
    }
  }

  pixelmap_size = oo;
  for(scan_row=0; scan_row<4; scan_row++) {
    pixelmapoffset[scan_row] = -(PANELWIDTH) * scan_row;//  * (scan_row * 8);
  }

  Timer1.initialize(1500);         
  Timer1.attachInterrupt(callback);
  
  Serial.begin(57600);

}

int wr = 0;

void loop() {
  if(Serial.available()){
    unsigned char cmd = Serial.read();
    if (cmd == 'C') {
      // clear screen
      for(int i=0; i<64*16; i++) {
        pixels[i] = '.';
      }
      Serial.write('K');
    }
    else if (cmd == 'H') {
      // home cursor
      Serial.write('K');
    }
    else if (cmd == 'W') {
      unsigned char start0 = Serial.read();
      unsigned char start1 = Serial.read();
      unsigned char bytes0 = Serial.read();
      unsigned char bytes1 = Serial.read();
      int bytes = (int)bytes1 * 256 + (int)bytes0;
      int start = (int)start1 * 256 + (int)start0;
      wr = start * 8;
      for (int i=0; i<bytes; i++) {
        unsigned char current = Serial.read();
        for(int i=0; i<8; i++) {
          unsigned char mask = 1 << i;
          pixels[i + wr] = ((current & mask) == mask) ? '1' : '.';
        }
        wr += 8;
        wr &= 1023;
      }
      Serial.write('K');
    }
    /* 
    for(int i=0; i<8; i++) {
      int mask = 1<<i;
      pixels[i + wr] = ((current & mask) == mask) ? '1' : '.';
    }
    wr += 8;
    wr %= 1024;
    */
  }
}