The Loco Positioning system (LPS) project is a set of hardware and software designed to implement a local positioning system. This wiki page aims at giving reference documentation for various parts of the system, for other documentation please see the following:

• Hardware documentation
• Getting Started Guide
• Loco Positioning Node firmware
• Crazyflie 2.0 firmware

To make the documentation easier to grasp there's a few terms that should be clear:

• Deck and node: These refer to pieces of hardware (Loco positioning deck, Loco positioning node)
• Tag and anchor: These refer to roles when ranging (i.g depending on configuration a node can act as either a tag or an anchor)
• Ranging mode: The protocol used for communicating between tags/anchors to create a measurement for the range (i.g TWR or TDoA)

The local positioning system is based on the DecaWave DWM1000 module. The system consists of a number of anchors that are 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.

• Reference set-up: Our current reference set-up showing node positioning and measurements
• Anchor set-up: How to set-up, configure and mount the anchor
• Configure the Crazyflie 2.0 in 2Mbit radio mode. This reduces interference with the UWB radio. If the configuration is changed a restart of the Crazyflie 2.0 is required.
• Crazyflie starting position: How to place the Crazyflie when using the LPS
• Configure LPS system mode wirelessly
• TDoA 3 set up
• Anchor low level configuration

• TDoA positioning principles: A description of how positioning using TDoA works
• TDoA2 VS TDoA3: A description the differences between TDoA2 and TDoA3

• TWR protocol: Documents the protocol used for Two Way Ranging (TWR)
• TDoA 2 protocol: Documentation of the TDoA 2 anchor protocol
• TDoA 3 protocol: Documentation of the TDoA 3 anchor protocol

• TDoA 3 implementation: Documentation of the TDoA 3 implementation

For working with the Loco positioning system there's a variety of tools available:

• Crazyflie Python Client - Used to set the anchor positions, validate anchor positions and to verify that the estimated position is reasonable
• LPS configuration tool - Used for firmware upgrades, changing mode and setting the address of Loco positioning nodes
• ROS - Used for controlling Crazyflies
• Autonomous sequence sctripting - Example showing how to use the Crazyflie Python Library to create scripted autonomous flights