Added AIRA ROS Bridge as submodule. Added README with install and launch instructions.

Author: akru

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "aira_ros_bridge"]
+	path = aira_ros_bridge
+	url = git://github.com/aira-dao/aira_ros_bridge.git

README.md

@@ -1,9 +1,80 @@
 # DroneEmployee ROS stack
 
-This repository contains ROS packages for **DroneEmployee** project.
+This repository contains ROS packages for the **DroneEmployee** project.
 
-Repository structure:
+## Hardware requirements
 
-* **drone_employee** - quadrotor behaviour
-* **small_atc** - small air traffic controller
-* **small_atc_msgs** - ATC common messages
+* UAV with MAVLink-compatible flight controller ([APM](http://ardupilot.com/), [PX4](http://px4.io/))
+* GPS/GLONASS module
+* Wireless Internet provider (LTE/3G modem)
+* Linux-compatible single board computer (RaspberryPi2)
+
+In other case you can use the *Software In The Loop* solution for testing described down.
+
+## Installation
+
+The **AIRA ROS Bridge** instance is needed, installation and simple usage described [there](https://github.com/aira-dao/aira_ros_bridge/tree/master/aira_ros_bridge).
+
+Software In The Loop instance installation described [there](https://github.com/aira-dao/aira-IoT/blob/master/ROS/dron_ros_tutorial/doc/Simulation.md).
+
+The next, create workspace and clone the repo:
+
+    $ mkdir workspace/src -p
+    $ cd workspace/src && catkin_init_workspace
+    $ git clone https://github.com/DroneEmployee/drone_employee_ros.git
+    $ cd ..
+
+Install dependecies by *rosdep*:
+    
+    $ rosdep install --from-paths src --ignore-src --rosdistro indigo -y
+
+Build the packages:
+
+    $ cakin_make
+
+### Solidity contracts
+
+The *smart contract* should be registered before using the **Drone Employee**.
+The contracts **small_atc.sol** and **drone_employee.sol** from [contracts repository](https://github.com/DroneEmployee/contracts) should be compiled by any solidity compiler, [online compier](https://chriseth.github.io/browser-solidity/) for example.
+Compiled contracts passed to network by any Ethereum client, returned contract address in future used by **AIRA ROS Bridge** as argument.
+
+## Launch
+
+Builded workspace should be added to ROS env:
+
+    $ source workspace/devel/setup.sh
+
+The next you should run [GEth node](https://github.com/ethereum/go-ethereum/wiki/geth) and [AIRA ROS Bridge](https://github.com/aira-dao/aira_ros_bridge/tree/master/aira_ros_bridge):
+
+    $ geth &
+    $ cd /path/to/aira_ros_bridge 
+    $ node start.js CONTRACT_ADDRESS 
+
+### The Air Traffic Controller
+
+Simple run the launch:
+
+    $ roslaunch small_atc atc.launch
+
+### The Drone Employee
+
+#### Simulation
+
+Run the SITL:
+
+    $ cd /path/to/ArduCopter
+    $ export PATH=$PATH:../ardupilot/Tools/autotest
+    $ fg_quad_view.sh & sim_vehicle.sh --map --console
+
+Launch the ROS node:
+    
+    $ roslaunch drone_employee apm_sitl.launch 
+
+#### Hardware
+
+Difference from upper is a using real **ArduPilot** or **PX4** hardware connected by UART or USB port.
+For using serial port in launch file you should set the **fcu_url** parameter:
+
+    $ roslaunch drone_employee apm_sitl.launch fcu_url:=/dev/ttyUSB0:115200
+
+The argument is a serial device and baudrate.