Add ZigBee component documentation.

source/_components/zigbee.markdown

@@ -0,0 +1,55 @@
+---
+layout: component
+title: "ZigBee"
+description: "Instructions on how to integrate a ZigBee network with Home Assistant."
+date: 2016-01-27 17:10
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: zigbee.png
+ha_category: DIY
+---
+
+[ZigBee](http://www.zigbee.org/what-is-zigbee/) integration for Home Assistant allows you to utilise modules such as the [XBee](http://www.digi.com/lp/xbee) as wireless General Purpose Input/Output (GPIO) devices. The component requires a local ZigBee device to be connected over a serial port. Through this it will send and receive commands to and from other devices on the ZigBee mesh network.
+
+There is currently support for the following device types within Home Assistant:
+
+- Binary Sensor (digital input pins)
+- Sensor (analog input pins and temperature sensor)
+- Light (digital output pins)
+- Switch (digital output pins)
+
+The local ZigBee device (assuming XBee) must have an up to date Router or Coordinator API firmware installed.
+
+## Configuration
+
+A `zigbee` section must be present in the `configuration.yaml` file and contain the following options as required:
+
+- **device**: The serial port to which the local ZigBee device is connected. Default: `/dev/ttyUSB0`
+
+- **baud**: The baud rate at which to communicate with the local ZigBee device. Default: `9600`
+
+#### Example
+
+```yaml
+zigbee:
+  device: /dev/ttyUSB0
+  baud: 115200
+```
+
+Or to simply use the defaults:
+
+```yaml
+zigbee:
+```
+
+To find the possible serial port names of your device, run:
+
+```bash
+$ ls /dev/ttyUSB*
+```
+
+<p class='note'>
+The port may also appear as /dev/ttyACM* if you're communicating with the ZigBee device through an Arduino.
+</p>