Raspberry Pi, Arduino, Node.js and serial port

Question

Im trying to talk to my arduino from a node.js server script. Here's my code: ``` var app = require('express')() , server = require('http').createServer(app) , io = require('socket.io').listen(server) , SerialPort = require('serialport').SerialPort; //SERIAL var portName = '/dev/ttyACM0'; var sp = new SerialPort(); // instantiate the serial port. sp.open(portName, { // portName is instatiated to be COM3, replace as necessary baudRate: 115200, // this is synced to what was set for the Arduino Code dataBits: 8, // this is the default for Arduino serial communication parity: 'none', // this is the default for Arduino serial communication stopBits: 1, // this is the default for Arduino serial communication flowControl: false // this is the default for Arduino serial communication }); //SERVER server.listen(80, '127.0.0.5'); app.get('/', function (req, res){ res.sendfile(__dirname + '/index.html'); }); io.sockets.on('connection', function (socket){ socket.emit('test', { test: 'Its Working'…

Accepted Answer

I think it is because empty arguments to `SerialPort`, which you later specify in open

```
var sp = new SerialPort(); // instantiate the serial port.
//then you open
sp.open(portName, { // portName is instatiated to be COM3, replace as necessary
```

From SerialPort npm project page

```
var SerialPort = require("serialport").SerialPort
var serialPort = new SerialPort("/dev/tty-usbserial1");

When opening a serial port, you can specify (in this order).
 1. Path to Serial Port - required.
 2. Options - optional and described below.
```

So you should specify all the arguments in SerialPort instead of open

```
var portName = '/dev/ttyACM0';
var sp = new SerialPort(portName, {
   baudRate: 115200,
   dataBits: 8,
   parity: 'none',
   stopBits: 1,
   flowControl: false
});
```

Raspberry Pi, Arduino, Node.js and serial port

Solution

Problem