Serial port not working?

I made a program that sends out data to my arduino which detects what was sent and then turns on the correct pin according to what key is pressed.

When using the arduino software from my windows computer the arduino sketch works fine, I can make each pin turn on and off by sending either W A S Or D.

When sending via node the RX light on the arduino flashes but nothing else happens.

Can anyone help?

Node.js program:

var httpServer = require('http').createServer(function(req, response){ /* Serve your static files */ })
httpServer.listen(8080);

var nowjs = require("now");
var everyone = nowjs.initialize(httpServer);

everyone.now.logStuff = function(msg){
    console.log(msg);
}

var SerialPort = require('serialport2').SerialPort;
var assert = require('assert');

var portName;

if (process.platform == 'win32') {
  portName = 'COM4';
} else if (process.platform == 'darwin') {
  portName = '/dev/cu.usbserial-A800eFN5';
} else {
  portName = '/dev/ttyUSB0';
}

var readData = '';
var sp = new SerialPort();

sp.on('close', function (err) {
  console.log('port closed');
});

sp.on('error', function (err) {
  console.error("error", err);
});

sp.on('open', function () {
  console.log('port opened... Press reset on the Arduino.');
});

sp.open(portName, {
  baudRate: 9600,
  dataBits: 8,
  parity: 'none',
  stopBits: 1,
  flowControl: false
});

everyone.now.forward = function() {
sp.write("w");
}

everyone.now.back = function() {
sp.write("s");
}

everyone.now.left = function() {
sp.write("a");
}

everyone.now.right = function() {
sp.write("d");
}

sp.on('data', function(data) {
  console.log(data.toString());
});

Arduino Program:

void setup(){
  Serial.begin(9600);
  Serial.write("READY");
  //Set all the pins we need to output pins
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop (){
  if (Serial.available() > 0) {

    //read serial as a character
    char ser = Serial.read();
    Serial.write(ser);
    //NOTE because the serial is read as "char" and not "int", the read value must be compared to character numbers
    //hence the quotes around the numbers in the case statement
    switch (ser) {
      case 'w':
        move(8);
        break;
      case 's':
        move(9);
        break;
      case 'a':
        move(10);
        break;
      case 'q':
        move(10);
        move(8);        
        break;
      case 'd':
        move(11);
        break;
      case 'e':
        move(11);
        move(8);
        break;
    }
  }
}

void move(int pin){
  Serial.print(pin);  
  digitalWrite(pin, HIGH);
  delay(1);
  digitalWrite(pin, LOW);
}

I recently dabbled into this. The Arduino automatically resets when it receives serial communication from most things other than the Arduino IDE. This is why you can send from the IDE but not node.js.

I have an Uno and put a capacitor between Reset and Ground.Here's a page with some good info on the subject.
Good luck. http://arduino.cc/playground/Main/DisablingAutoResetOnSerialConnection

I use node on a daily basis to send actions to my Arduino via usb or via bt and it works great in both cases. I think your problem comes from sending letters. You should send a buffer instead, with the ascii value of the letter, just like that:

myPort.write(Buffer([myValueToBeSent]));

also, for this, I think you would be better with some "logic" interface, with data headers, number of actions, stuff like that. It is no required for you but it will make your code more robust and easier to modify in the future.

Here is an example of how I do it. First, Node:

var dataHeader = 0x0f, //beginning of the data stream, very useful if you intend to send a batch of actions
myFirstAction = 0x01,
mySecondAction = 0x02,
myThirdAction = 0x03;

You then call them like you did:

everyone.now.MyBatchOfActions = function() {
    sp.write(Buffer([dataHeader]));

    sp.write(Buffer([0x03])); // this is the number of actions for the Arduino code

    sp.write(Buffer([myFirstAction]));
    sp.write(Buffer([mySecondAction]));
    sp.write(Buffer([myThirdAction]));
}

This way it is easy on the Arduino to Serial.read() the data: (Note that you need to define data header and data footer somewhere)

void readCommands(){
    while(Serial.available() > 0){

        // Read first byte of stream.
        uint8_t numberOfActions;
        uint8_t recievedByte = Serial.read();

        // If first byte is equal to dataHeader, lets do
        if(recievedByte == DATA_HEADER){
            delay(10);

            // Get the number of actions to execute
            numberOfActions = Serial.read();

            delay(10);

            // Execute each actions
            for (uint8_t i = 0 ; i < numberOfActions ; i++){

                // Get action type
                actionType = Serial.read();

                if(actionType == 0x01){
                    // do you first action
                }
                else if(actionType == 0x02{
                    // do your second action
                }
                else if(actionType == 0x03){
                    // do your third action
                }
            }
        }
    }
}

I hope I'm clear and I hope it helps! Cheers!