node package manager

xbee

This module lets you bridge the real world to Node.js. Connect to sensors, robots, turn things on and off, take remote measurements. In fact if you find a creative use for this stuff, let me know! I'd be proud to hear of it being taken advantage of.

(made up Javascript code to get your imagination going)

frontdoor.on("open", function() {
  if (alarm.state == "on") {
    alarm.sound();
    hounds.release();
  } else {
    lights.switchOn();
    voice.speak("Welcome home");
  }
});

Background

Digi's xbee modules are good for quickly building low power wireless networks.

They can be connected to a computer over RS232 and communicated on using a standard serial port.

Even easier, with something like the XBee USB Explorer by SparkFun, you can connect to them easily over USB.

This work is inspired by:

Setup

I have my xbee coordinator radio connected to the computer running Node. Crucially, the coordinator is in xbee's API mode - this is required to allow you to send remote instructions, and so on.

My remote xbee network modules send periodic measurements and I can push them to web browsers, save them in a database, etc.

I can also use this library to send remote commands and query remote xbee modules. For instance, setting a digital output on a remote module could turn a light on, or a motor, or a laser beam - up to you!

How To Use

Like node-serialport, using this 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

You'll need serialport as well (this module doesn't depend on it, but it provides a parser so this is the intended use pattern)

npm install serialport
npm install xbee

To Use

Open a serial port and give the xbee parser as an option:

var serial_xbee = new SerialPort("/dev/ttyUSB0", { 
  parser: xbee.packetParser()
});

Then listen for incoming xbee packets like this:

serial_xbee.on("data", function(data) {
  console.log('xbee data received:', data.type);    
});

(the data object passed has lot more packet-type-dependent properties)

Send remote AT commands (e.g. query remote module, or "release the hounds"):

// execute an AT command on a remote xbee module
function RemoteAT(cmd, val, remote64, remote16) {
  var atc = new xbee.RemoteATCommand();
  atc.setCommand(cmd);
  atc.commandParameter = val;
  atc.destination64 = remote64;
  atc.destination16 = remote16;
  b = atc.getBytes();
  serial_xbee.write(b);
  //console.log('Wrote bytes to serial port', b);
}

// simple example: query ATD0 on remote xbee module.
var remote64 = [0x00,0x13,0xa2,0x00,0x40,0x7a,0x1f,0x95];  // <-- you'll need to replace this with the 64-bit hex address of your module
var remote16 = [0xff,0xfe]; // <-- put the 16 bit address of remote module here, if known. Otherwise use [0xff, 0xfe]

RemoteAT('D0', null, remote64, remote16);

See example.js for a full working example (you'll need to use your own xbee IDs, though).

Licence

Creative Commons License
This work by Richard Morrison is licensed under a Creative Commons Attribution-ShareAlike 2.0 UK: England & Wales License.
Based on a work at github.com.