64x32 ledpanel driver for node.js

ledpanel.js

var SerialPort = require("serialport");

// https://github.com/tompreston/4x5-Font/blob/master/4x5-font.js
var font4x5 = {
    '': [0x0, 0x0, 0x0, 0x0, 0x0],
    '!': [0x4, 0x4, 0x4, 0x0, 0x4],
    '#': [0x6, 0xf, 0x6, 0xf, 0x6],
    '\'': [0x0, 0xa, 0x0, 0x0, 0x0],
    '%': [0x7, 0xe, 0x4, 0x7, 0xe],
    '$': [0x7, 0xa, 0x6, 0x5, 0xe],
    '"': [0x1, 0x2, 0x0, 0x0, 0x0],
    '&': [0x2, 0x5, 0x6, 0xa, 0x5],
    ')': [0x4, 0x2, 0x2, 0x2, 0x4],
    '(': [0x4, 0x8, 0x8, 0x8, 0x4],
    '+': [0x0, 0x2, 0x7, 0x2, 0x0],
    '*': [0x0, 0x6, 0xf, 0x6, 0x0],
    '-': [0x0, 0x0, 0x0, 0xf, 0x0],
    ',': [0x0, 0x0, 0x0, 0x2, 0x4],
    '/': [0x1, 0x1, 0x2, 0x4, 0x8],
    '.': [0x0, 0x0, 0x0, 0x0, 0x4],
    '1': [0x2, 0x6, 0x2, 0x2, 0x2],
    '0': [0x6, 0xb, 0xf, 0xd, 0x6],
    '3': [0xe, 0x1, 0x6, 0x1, 0xe],
    '2': [0xe, 0x1, 0x6, 0x8, 0xf],
    '5': [0xf, 0x8, 0xe, 0x1, 0xe],
    '4': [0x2, 0x6, 0xa, 0xf, 0x2],
    '7': [0xf, 0x1, 0x2, 0x4, 0x8],
    '6': [0x6, 0x8, 0xe, 0x9, 0x6],
    '8': [0x6, 0x9, 0x6, 0x9, 0x6],
    '9': [0x6, 0x9, 0xf, 0x1, 0x6],
    ':': [0x0, 0x4, 0x0, 0x4, 0x0],
    ';': [0x0, 0x4, 0x0, 0x4, 0x8],
    '<': [0x2, 0x4, 0x8, 0x4, 0x2],
    '=': [0x0, 0xf, 0x0, 0xf, 0x0],
    '>': [0x4, 0x2, 0x1, 0x2, 0x4],
    '?': [0x6, 0x9, 0x2, 0x0, 0x2],
    '@': [0x6, 0xd, 0xb, 0x8, 0x6],
    'A': [0x4, 0xa, 0xe, 0xa, 0xa],
    'B': [0xe, 0x9, 0xe, 0x9, 0xe],
    'C': [0x6, 0x9, 0x8, 0x9, 0x6],
    'D': [0xe, 0x9, 0x9, 0x9, 0xe],
    'E': [0xf, 0x8, 0xe, 0x8, 0xf],
    'F': [0xf, 0x8, 0xe, 0x8, 0x8],
    'G': [0x6, 0x8, 0xb, 0x9, 0x6],
    'H': [0x9, 0x9, 0xf, 0x9, 0x9],
    'I': [0xe, 0x4, 0x4, 0x4, 0xe],
    'J': [0x1, 0x1, 0x1, 0x9, 0x6],
    'K': [0x9, 0xa, 0xc, 0xa, 0x9],
    'L': [0x8, 0x8, 0x8, 0x8, 0xf],
    'M': [0x9, 0xf, 0xf, 0x9, 0x9],
    'N': [0x9, 0xd, 0xf, 0xb, 0x9],
    'O': [0x6, 0x9, 0x9, 0x9, 0x6],
    'P': [0xe, 0x9, 0xe, 0x8, 0x8],
    'Q': [0x6, 0x9, 0x9, 0xb, 0x7],
    'R': [0xe, 0x9, 0xe, 0xa, 0x9],
    'S': [0x7, 0x8, 0x6, 0x1, 0xe],
    'T': [0xe, 0x4, 0x4, 0x4, 0x4],
    'U': [0x9, 0x9, 0x9, 0x9, 0x6],
    'V': [0x9, 0x9, 0x9, 0x6, 0x6],
    'W': [0x9, 0x9, 0xf, 0xf, 0x9],
    'X': [0x9, 0x9, 0x6, 0x9, 0x9],
    'Y': [0x9, 0x5, 0x2, 0x2, 0x2],
    'Z': [0xf, 0x2, 0x4, 0x8, 0xf],
    '[': [0xe, 0x8, 0x8, 0x8, 0xe],
    '\\': [0x8, 0x8, 0x4, 0x2, 0x1],
    ']': [0x7, 0x1, 0x1, 0x1, 0x7],
    '^': [0x4, 0xa, 0x0, 0x0, 0x0],
    '_': [0x0, 0x0, 0x0, 0x0, 0xf],
    '`': [0x4, 0x2, 0x0, 0x0, 0x0],
    'a': [0x0, 0x5, 0xb, 0xb, 0x5],
    'b': [0x8, 0x8, 0xe, 0x9, 0xe],
    'c': [0x0, 0x7, 0x8, 0x8, 0x7],
    'd': [0x1, 0x1, 0x7, 0x9, 0x7],
    'e': [0x0, 0x6, 0xf, 0x8, 0x7],
    'f': [0x3, 0x4, 0xe, 0x4, 0x4],
    'g': [0x7, 0x9, 0x7, 0x1, 0x7],
    'h': [0x8, 0x8, 0xe, 0x9, 0x9],
    'i': [0x0, 0x2, 0x0, 0x2, 0x2],
    'j': [0x1, 0x0, 0x1, 0x1, 0x6],
    'k': [0x8, 0xa, 0xc, 0xa, 0x9],
    'l': [0xc, 0x4, 0x4, 0x4, 0xe],
    'm': [0x0, 0x9, 0xf, 0xf, 0x9],
    'n': [0x0, 0xe, 0x9, 0x9, 0x9],
    'o': [0x0, 0x6, 0x9, 0x9, 0x6],
    'p': [0x0, 0xe, 0x9, 0xe, 0x8],
    'q': [0x0, 0x6, 0x9, 0x7, 0x1],
    'r': [0x0, 0xb, 0xc, 0x8, 0x8],
    's': [0x0, 0x7, 0x4, 0x2, 0xe],
    't': [0x4, 0xe, 0x4, 0x4, 0x3],
    'u': [0x0, 0x9, 0x9, 0x9, 0x6],
    'v': [0x0, 0x9, 0x9, 0x6, 0x6],
    'w': [0x0, 0x9, 0xf, 0xf, 0x6],
    'x': [0x0, 0x9, 0x6, 0x6, 0x9],
    'y': [0x0, 0x9, 0x7, 0x1, 0x6],
    'z': [0x0, 0xf, 0x2, 0x4, 0xf],
    '{': [0x6, 0x4, 0xc, 0x4, 0x6],
    '|': [0x4, 0x4, 0x0, 0x4, 0x4],
    '}': [0xc, 0x4, 0x6, 0x4, 0xc],
    '~': [0x0, 0x0, 0x5, 0xa, 0x0],
};

var serialPort = new SerialPort.SerialPort('/dev/tty.usbmodem1421', {
  baudrate: 57600
});

var open = false;

var pixels = new Array(64*16);

serialPort.on("open", function () {
  console.log('opened');
  serialPort.write(new Buffer('C'));
  open = true;
});

var scanrow = 0;

function queueSend() {
  // update one row

  var o = scanrow * 8;
  var bytes = 8;

  var packet = new Buffer(5 + bytes);

  packet[0] = 'W'.charCodeAt(0);

  packet[1] = o & 255;
  packet[2] = o >> 8;

  packet[3] = bytes & 255;
  packet[4] = bytes >> 8;

  var o2 = scanrow * 64;
  for(var j=0; j<bytes; j++) {
    var b = 0;
    for(var k=0; k<8; k++) {
      if (pixels[o2 ++]) b |= 1 << k;
    }
    packet[5 + j] = b;
  }

  // console.log('sending: ' + packet);

  serialPort.write(packet);

  scanrow ++;
  scanrow %= 16;
}

function gotAck() {
  setTimeout(queueSend.bind(this), 0);
}

serialPort.on("data", function (data) {
  // console.log('got data', data.toString());
  if (data.toString().substring(0, 1) == 'K') { gotAck(); }
});

serialPort.on("close", function (data) {
  open = false;
  console.log('closed');
});

var fr = 0;

function setPixel(x, y, on) {
  if (x < 0 || y < 0 || x >= 64 || y >= 16)
    return;
  pixels[Math.floor(y) * 64 + Math.floor(x)] = on;
}

function drawChar(ch, x, y) {
  var chardata = font4x5[ch];
  // console.log('drawChar', ch, chardata);
  if (chardata) {
    for(var r=0; r<5; r++) {
      for(var c=0; c<4; c++) {
        var b = chardata[r];
        var mask = 1 << (3-c);
        if ((b & mask) == mask)
          setPixel(x+c, y+r, true);
      }
    }
  }
}

function drawString(str, x, y, spacing) {
  for(var c=0; c<str.length; c++) {
    drawChar(str.substring(c, c+1), x + c*(5 + spacing || 0), y);
  }
}

setInterval(function() {
  var o = 0;
  for(var y=0; y<16; y++) {
    for(var x=0; x<64; x++) {
 //     pixels[o] = (((x ^ y) % 16) == (fr % 16));
      pixels[o] = false;
      o ++;
    }
  }

  var str = 'Hello world!';
  for(var c=0; c<str.length; c++) {
    drawChar(str.substring(c, c+1), 3 + 5 * c + 5 * Math.sin(fr / 13.0 + c / 5.0 ), 3 + 3.0 * Math.sin(fr / 10.0 + c / 2.1));
  }

  drawString((new Date()).toString().substring(16, 24), 12 + 12 * Math.sin(fr/40.0), 11, 0);

  o = 0;
  var all = '';
  for(var y=0; y<16; y++) {
    for(var x=0; x<64; x++) {
      all += pixels[o] ? '()' : '  '
      o ++;
    }
    all += '\n';
  }

  console.log('\033[2J' + all);

  fr ++;
}, 40);