LCD proof of concept for johnny-five

lcd.js

// Wire up LCD as described here:
// http://learn.adafruit.com/character-lcds/overview

var five = require("johnny-five"),
    board, lcd;

board = new five.Board();

board.on("ready", function() {

  lcd = {
    rsPin: 7, // LCD pin 4
    // rwPin:, // LCD pin 5, only needed when reading from display
    enPin: 8, // LCD pin 6
    dataPins: [12, 11, 10, 9] // D7 to D4. LCD pins 14, 13, 12, 11
  };

  var sleep = function(milliSeconds) {
    var startTime = new Date().getTime();
    while (new Date().getTime() < startTime + milliSeconds);
  };

  var highLowFromBinary = function(number) {
    return number === 1 ? board.firmata.HIGH : board.firmata.LOW;
  };

  var sendCommand = function(command) {
    board.digitalWrite(lcd.dataPins[0], highLowFromBinary(command[0]));
    board.digitalWrite(lcd.dataPins[1], highLowFromBinary(command[1]));
    board.digitalWrite(lcd.dataPins[2], highLowFromBinary(command[2]));
    board.digitalWrite(lcd.dataPins[3], highLowFromBinary(command[3]));

    // Pulse the EN pin to send first nibble
    board.digitalWrite(lcd.enPin, board.firmata.HIGH);
    board.digitalWrite(lcd.enPin, board.firmata.LOW);

    board.digitalWrite(lcd.dataPins[0], highLowFromBinary(command[4]));
    board.digitalWrite(lcd.dataPins[1], highLowFromBinary(command[5]));
    board.digitalWrite(lcd.dataPins[2], highLowFromBinary(command[6]));
    board.digitalWrite(lcd.dataPins[3], highLowFromBinary(command[7]));

    // Pulse the EN pin to send second nibble
    board.digitalWrite(lcd.enPin, board.firmata.HIGH);
    board.digitalWrite(lcd.enPin, board.firmata.LOW);
  };

  var writeMessage = function() {
    board.digitalWrite(lcd.rsPin, board.firmata.LOW);
    sendCommand([0,0,0,0,0,0,0,1]);

    board.digitalWrite(lcd.rsPin, board.firmata.HIGH);
    sendCommand([0,1,0,0,1,0,1,0]);
    sleep(200);
    sendCommand([0,1,1,0,1,1,1,1]);
    sleep(200);
    sendCommand([0,1,1,0,1,0,0,0]);
    sleep(200);
    sendCommand([0,1,1,0,1,1,1,0]);
    sleep(200);
    sendCommand([0,1,1,0,1,1,1,0]);
    sleep(200);
    sendCommand([0,1,1,1,1,0,0,1]);
    sleep(200);
    sendCommand([0,0,1,0,1,1,0,1]);
    sleep(200);
    sendCommand([0,1,1,0,0,1,1,0]);
    sleep(200);
    sendCommand([0,1,1,0,1,0,0,1]);
    sleep(200);
    sendCommand([0,1,1,1,0,1,1,0]);
    sleep(200);
    sendCommand([0,1,1,0,0,1,0,1]);

    board.digitalWrite(lcd.rsPin, board.firmata.LOW);
  };

  // RS to low (for command mode), EN to low to start
  board.digitalWrite(lcd.rsPin, board.firmata.LOW);
  board.digitalWrite(lcd.enPin, board.firmata.LOW);

  // Switch to 4-bit mode
  board.digitalWrite(lcd.dataPins[0], board.firmata.LOW);
  board.digitalWrite(lcd.dataPins[1], board.firmata.LOW);
  board.digitalWrite(lcd.dataPins[2], board.firmata.HIGH);
  board.digitalWrite(lcd.dataPins[3], board.firmata.LOW);
  board.digitalWrite(lcd.enPin, board.firmata.HIGH);
  board.digitalWrite(lcd.enPin, board.firmata.LOW);
  // Set to two-line mode
  sendCommand([0,0,1,0,1,0,0,0]);

  // Clear display and turn it on
  sendCommand([0,0,0,0,0,0,0,1]);
  sendCommand([0,0,0,0,1,1,1,1]);

  // Write some text
  writeMessage();

});

Also, see https://gist.github.com/3185390#L34 for turning an integer into a sequence of binary digits, which may be useful.