serialport

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Version: 1.3.0 - Released January 15, 2014

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Imagine a world where you can write JavaScript to control blenders, lights, security systems, or even robots. Yes, I said robots. That world is here and now with node-serialport. It provides a very simple interface to the low level serial port code necessary to program Arduino chipsets, X10 wireless communications, or even the rising Z-Wave and Zigbee standards. The physical world is your oyster with this goodie. For a full break down of why we made this, please read NodeBots - The Rise of JS Robotics.

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Robots, you say?

This library is admittedly a base level toolkit for building amazing things with real world (including robots). Here are a couple of those amazing things that leverage node-serialport:

• firmata Talk natively to Arduino using the firmata protocol.
• tmpad source - a DIY midi pad using infrared, arduino, and nodejs. Video
• duino - A higher level framework for working with Arduinos in node.js.
• Arduino Drinking Game Extravaganza - AKA "The Russian" a hexidecimal drinking game for geeks by Uxebu presented at JSConf EU 2011.
• Arduino controlling popcorn.js - Controlling a popcorn.js video with an Arduino kit.
• Robotic JavaScript - The first live presentation of the node-serialport code set as presented at JSConf EU 2010.
• devicestack - This module helps you to represent a device and its protocol.
• reflecta A communication protocol that combines Arduino Libraries and NodeJS into an integrated system.

For getting started with node-serialport, we recommend you begin with the following articles:

• Arduino Node Security Sensor Hacking - A great all around "how do I use this" article.
• NodeBots - The Rise of JS Robotics - A survey article of why one would want to program robots in JS.
• Johnny-Five Getting Started Guide - Introduction to using the high level Johnny-Five library (awesome).

How To Use

Using node-serialport is pretty easy because it is pretty basic. It provides you with the building block to make great things, it is not a complete solution - just a cog in the (world domination) machine.

To Install

This assumes you have everything on your system necessary to compile ANY native module for Node.js. This may not be the case, though, so please ensure the following are true for your system before filing an issue about "Does not install". For all operatings systems, please ensure you have Python 2.x installed AND not 3.0, node-gyp (what we use to compile) requires Python 2.x.

Windows:

• Windows 7 or Windows 8.1 are supported.
• Install Visual Studio Express 2013 for Windows Desktop.
• If you are hacking on an Arduino, be sure to install the drivers.
• Install node.js 0.10.x matching the bitness (32 or 64) of your operating system.
• Install Python 2.7.6 matching the bitness of your operating system. For any questions, please refer to their FAQ. Default settings are perfect.
• Open the 'Visual Studio Command Prompt' and add Python to the path.

Visual Studio 2013 is not yet supported by node 0.10.x but the latest version of node-gyp on npm does support it. Use the below workaround until node 0.10.x is updated.

   set path=%path%;C:\Python27
   npm install node-gyp -g
   git clone https://github.com/voodootikigod/node-serialport.git
   cd node-serialport
   node-gyp configure
   node-gyp build

Mac OS X:

Ensure that you have at a minimum the xCode Command Line Tools installed appropriate for your system configuration. If you recently upgraded the OS, it probably removed your installation of Command Line Tools, please verify before submitting a ticket.

Desktop (Debian/Ubuntu) Linux:

You know what you need for you system, basically your appropriate analog of build-essential. Keep rocking!

   sudo apt-get install build-essential
   npm install serialport

Raspberry Pi Linux:

• Starting with a a vanilla New Out of the Box Software (NOOBS) Raspbian image (currently tested: 5/25/2013)
• Log into your Raspberry Pi through whatever means works best and ensure you are on a terminal prompt for the remaining steps. This could be local or through an SSH (or a serial connection if you like).
• Issue the following commands to ensure you are up to date:

   sudo apt-get update
   sudo apt-get upgrade -y

• Download and install node.js:

   wget http://nodejs.org/dist/v0.10.12/node-v0.10.12-linux-arm-pi.tar.gz
   tar xvfz node-v0.10.12-linux-arm-pi.tar.gz
   sudo mv node-v0.10.12-linux-arm-pi /opt/node/

• Set up your paths correctly:

   echo 'export PATH="$PATH:/opt/node/bin"' >> ~/.bashrc
   source ~/.bashrc

• Install using npm, note this will take a while as it is actually compiling code and that ARM processor is getting a workout.

   npm install serialport

To Use

Opening a serial port:

var SerialPort = require("serialport").SerialPort
var serialPort = new SerialPort("/dev/tty-usbserial1", {
  baudrate: 57600
});

When opening a serial port, you can specify (in this order).

1. Path to Serial Port - required.
2. Options - optional and described below.

The options object allows you to pass named options to the serial port during initialization. The valid attributes for the options object are the following:

• baudrate: Baud Rate, defaults to 9600. Must be one of: 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1800, 1200, 600, 300, 200, 150, 134, 110, 75, or 50.
• databits: Data Bits, defaults to 8. Must be one of: 8, 7, 6, or 5.
• stopbits: Stop Bits, defaults to 1. Must be one of: 1 or 2.
• parity: Parity, defaults to 'none'. Must be one of: 'none', 'even', 'mark', 'odd', 'space'
• buffersize: Size of read buffer, defaults to 255. Must be an integer value.
• parser: The parser engine to use with read data, defaults to rawPacket strategy which just emits the raw buffer as a "data" event. Can be any function that accepts EventEmitter as first parameter and the raw buffer as the second parameter.

Note, we have added support for either all lowercase OR camelcase of the options (thanks @jagautier), use whichever style you prefer.

open event

You MUST wait for the open event to be emitted before reading/writing to the serial port. The open happens asynchronously so installing 'data' listeners and writing before the open event might result in... nothing at all.

Assuming you are connected to a serial console, you would for example:

serialPort.on("open", function () {
  console.log('open');
  serialPort.on('data', function(data) {
    console.log('data received: ' + data);
  });
  serialPort.write("ls\n", function(err, results) {
    console.log('err ' + err);
    console.log('results ' + results);
  });
});

You can also call the open function, in this case instanciate the serialport with an additional flag.

var SerialPort = require("serialport").SerialPort
var serialPort = new SerialPort("/dev/tty-usbserial1", {
  baudrate: 57600
}, false); // this is the openImmediately flag [default is true]

serialPort.open(function () {
  console.log('open');
  serialPort.on('data', function(data) {
    console.log('data received: ' + data);
  });
  serialPort.write("ls\n", function(err, results) {
    console.log('err ' + err);
    console.log('results ' + results);
  });
});

List Ports

You can also list the ports along with some metadata as well.

var serialPort = require("serialport");
serialPort.list(function (err, ports) {
  ports.forEach(function(port) {
    console.log(port.comName);
    console.log(port.pnpId);
    console.log(port.manufacturer);
  });
});

Parsers

Out of the box, node-serialport provides two parsers one that simply emits the raw buffer as a data event and the other which provides familiar "readline" style parsing. To use the readline parser, you must provide a delimiter as such:

var serialport = require("serialport");
var SerialPort = serialport.SerialPort; // localize object constructor

var sp = new SerialPort("/dev/tty-usbserial1", {
  parser: serialport.parsers.readline("\n")
});

To use the raw parser, you just provide the function definition (or leave undefined):

var serialport = require("serialport");
var SerialPort = serialport.SerialPort; // localize object constructor

var sp = new SerialPort("/dev/tty-usbserial1", {
  parser: serialport.parsers.raw
});

You can get updates of new data from the Serial Port as follows:

serialPort.on("data", function (data) {
  sys.puts("here: "+data);
});

You can write to the serial port by sending a string or buffer to the write method as follows:

serialPort.write("OMG IT WORKS\r");

Enjoy and do cool things with this code.

Reference Guide

Methods

SerialPort (path, options, openImmediately, callback)

Create a new serial port on path.

path

The system path of the serial port to open. For example, /dev/tty on Mac/Linux or COM1 on Windows.

options (optional)

Port configuration options.

• baudRate
• dataBits
• stopBits
• parity
• rtscts
• xon
• xoff
• xany
• flowControl
• bufferSize
• parser
• encoding
• dataCallback
• disconnectedCallback

openImmediately (optional)

Attempts to open a connection to the serial port on process.nextTick. The default is true. Set to false to manually call open() at a later time.

callback (optional)

Called when a connection has been opened. The callback should be a function that looks like: function (error) { ... }

.open (callback)

Opens a connection to the given serial port.

callback (optional)

Called when a connection has been opened. The callback should be a function that looks like: function (error) { ... }

.write (buffer, callback)

Writes data to the given serial port.

buffer

The buffer parameter accepts a Buffer object, or a type that is accepted by the Buffer constructor (ex. an array of bytes or a string).

callback (optional)

Called once the write operation returns. The callback should be a function that looks like: function (error) { ... } Note: The write operation is non-blocking. When it returns, data may still have not actually been written to the serial port. See drain().

.pause ()

Pauses an open connection.

.resume ()

Resumes a paused connection.

.flush (callback)

Flushes data received but not read. See tcflush() for Mac/Linux and FlushFileBuffers for Windows.

callback (optional)

Called once the flush operation returns. The callback should be a function that looks like: function (error) { ... }

.drain (callback)

Waits until all output data has been transmitted to the serial port. See tcdrain() for more information.

callback (optional)

Called once the drain operation returns. The callback should be a function that looks like: function (error) { ... }

Example

Writes data and waits until it has finish transmitting to the target serial port before calling the callback.

function writeAndDrain (data, callback) {
  sp.write(data, function () {
    sp.drain(callback);
  });
}

.close (callback)

Closes an open connection.

callback (optional)

Called once a connection is closed. Closing a connection will also remove all event listeners. The callback should be a function that looks like: function (error) { ... }

Events

.on('open', callback)

.on('data', callback)

.on('close', callback)

.on('error', callback)