MemoryLCD.js

/* Copyright (c) 2013 Gordon Williams, Pur3 Ltd. See the file LICENSE for copying permission. */
exports.connect = function(/*=SPI*/_spi, /*=PIN*/_cs, /*=PIN*/_vcom, width, height, callback) {
  var g = Graphics.createArrayBuffer(width,height,1);
  var spi = _spi;
  var cs = _cs;
  var vcom = _vcom;
  var vcomstate = false;

  digitalWrite(cs,0); // CS on
  spi.send(0b00000100); // clear display
  digitalWrite(cs,0); // CS off

  setTimeout(function() {
    digitalWrite(cs,0); // CS on
    spi.send(0b00000000); // all normal
    digitalWrite(cs,0); // CS off
    if (callback) callback();
  }, 10);  
  /* Note: it's recommended you toggle vcom every second, but doing it every 5
     allows Espruino to properly enter deep sleep modes */
  if (vcom) {
    setInterval(function() {
      digitalWrite(vcom, vcomstate=!vcomstate);
    }, 5000);
  }
  
  g.flip = function () {
    digitalWrite(cs,1); // CS on
    spi.send([0b00000001,1]); // update, 1st row
    var w = g.getWidth()>>3;
    for (var y=0;y<g.getHeight();y++) {
      spi.send(new Uint8Array(g.buffer,y*w,w));
      spi.send([0,y+2]); // pad and do 2nd row
    }
    digitalWrite(cs,0); // CS off
  };
  return g;
};