The local positioning system is based on the DecaWave DWM1000 module. The system consists of a number of anchors that's continuously pinged from the Crazyflie 2.0 deck that's based on the same module. The anchors are placed around the room at known positions (for now).

The hardware consists two parts, nodes and decks.

• Loco positioning node: Mainly aimed as an anchor but can be used as a tag or UWB radio transceiver and sniffer.
• Loco positioning deck: USB radio deck to be installed on Crazyflie 2.0

The ROS module for positioning with the LPS is available on Github: https://github.com/bitcraze/lps-ros. It has been developed and tested on ROS Indigo running on Ubuntu 14.04

To get started from a newly installed ubuntu:

1. Install ROS: http://wiki.ros.org/indigo/Installation/Ubuntu
2. Create your workspace: http://wiki.ros.org/ROS/Tutorials/InstallingandConfiguringROSEnvironment#Create_a_ROS_Workspace
3. Clone https://github.com/bitcraze/lps-ros and https://github.com/whoenig/crazyflie_ros in the workspace src folder
4. Run catkin_make to build the packages
5. Source the workspace devel/setup.bash again
6. Run rosdep install bitcraze_lps_estimator to install dependencies

The position of the anchor has to be entered in a configuration file. The file should be data/anchor_pos.yaml. An example is present in the data folder:

anchor_pos.yaml

n_anchors: 6
anchor0_pos: [  0,   0, 1.85]
anchor1_pos: [  0,   2, 1.85]
anchor2_pos: [  4,   2, 1.85]
anchor3_pos: [  4,   0, 1.85]
anchor4_pos: [1.3,   1, 1.85]
anchor5_pos: [2.6,   1, 1.85]

The positions are in meter, [x, y, z], from the origin.

When this file is configured, the dwm_loc.launch launch configuration will connect the crazyflie with the right log setup, launch the particle filter and the visualization:

$ roslaunch bitcraze_lps_estimator dwm_loc.launch uri:=radio://0/40/2M