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:

• voodootikigod's serialport module (in fact you're going to need this to use this package)
• "Building Wireless Sensor Networks" by Rob Faludi

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

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.