SociTrack is a system for using ultra-wideband RF time-of-flight processing to perform indoor ranging and localization. It incorporates the SquarePoint module, containing a DecaWave DW1000 radio for UWB packet transmission and timestamping. This module provides node-to-node ranges over an I²C interface which can then be stored locally or transmitted externally.

The SociTrack system is composed of several hardware pieces. At its core is the SquarePoint module, a 30mm x 15mm PCB that encompasses all of the core ranging hardware and firmware. SquarePoint is provided as an EAGLE board that allows for direct integration as a design block as part of the Lab11 EAGLE library. One example of a project that uses the SquarePoint module is the TotTag, which comprises an all-in-one tracking and localization system for mobile nodes. The TotTag hardware includes three UWB antennas and a Bluetooth Low Energy (BLE) radio, plus a battery charging circuit, SD card for data logging, accelerometer, USB connectivity, and integrated sensor fusion. TotTag is able to provide ranges and position estimates directly to a mobile phone application in real-time and can be configured on-the-fly using a simple user interface over Summon.

SquarePoint, an EAGLE design block for UWB ranging, includes the following components:

• DecaWave DW1000 UWB radio
• STMicroelectronics STM32F091CCU6 MCU
• RF switch

The MCU contains all of the necessary code to control the DW1000 and run the ranging protocol. This module provides a simple abstraction layer for quick integration with a carrier board over an I²C interface without having to worry about any underlying implementation details.

The TotTag is a self-contained PCB which utilizes SquarePoint to provide ranging data for human interaction tracking. It includes:

• The SquarePoint module - 3 UWB antennas
• Nordic Semiconductors nRF52840 BLE radio
• 3.3V LDO designed to be used with 4.2V LiPo batteries
• Battery charge management controller
• SD card holder
• microUSB connector including FTDI FT232R for debugging
• 3-axis accelerometer

The TotTag is designed to be a device that can be used as a ranging anchor, a mobile tag, or a hybrid combination of both. It offers both infrastructure-free and infrastructure-based network processing and allows for centimeter-accurate, multi-day deployments. Both the schematic and board design are open-source and can be found in the hardware/tottag folder; a suitable 3D printable case is also provided in hardware/cad/tottag-case.

The SociTrack software is freely available as an open-source Git repository. When cloning this repository, be sure to do

git clone --recursive https://github.com/lab11/socitrack.git

or to later run

git submodule init && git submodule sync

so that all submodules are cloned as well. All of the supporting libraries and build tools are in submodules for the various hardware platforms used in this project.

Found in software/squarepoint, the core firmware that enables the SquarePoint module to work includes all of the logic implementing our custom ranging protocol on top of the DecaWave DW1000 UWB radio. It makes use of frequency and antenna diversity and leverages both one-way and two-way ToF ranging to achieve efficient and reliable ranging in various environments. The firmware architecture supports multiple runtime modalities that can be selected on-the-fly; currently, we officially support:

• Standard: the full ranging protocol, using maximal diversity to achieve highly-reliable ranging measurements over 30 different channels.
• Calibration: automatically triggered by our calibration scripts, allowing for automated board-specific calibration functions which are then applied to future ranging measurements.

The TotTag code, located in software/tottag, implements a BLE application that uses the SquarePoint module as an I²C slave and provides for external BLE connectivity. It exposes BLE services to configure and enable the device, to set the current time to enable accurate timestamping of ranging data, as well as to access ranging data in real-time.

The tools in the software/tottag/mobile_app directory interact with TotTag and read data across the BLE interface. They uses the Summon app (Google Play, App Store) to easily access and interact with the TotTag devices. The target website must be configured in the TotTag code and can be hosted on a personal domain; we recommend the use of a link shortener to reduce the BLE advertisement length.

This project requires the GNU ARM Embedded Toolchain. Please be aware that the some Linux distros provide out-of-date versions of this tool; as such, we strongly recommend that you install the newest version directly from ARM.