Cycling power meter final year project

Oscar Varney and Jotham Gates, 2024

This is the code repository for a Final Year Project (FYP) to develop a crankset and power meter for Human Powered Vehicles (HPVs).

Contents

• Getting started
• Schematic and PCB layout
• Code
  • Libraries
  • Tools for updating dates of changed files and versions
    • Git Hook for checking dates are correct before committing
  • Doxygen documentation
• Scripts and testing

Getting started

• See here for some instructions on getting the power meter to work with MQTT and WiFi.
• See here for information on configuring the power meter.
• See here for information on MQTT topics used when communicating using this protocol.
• If you are a member of MHP, then the Notion page for this project can be found here.

Schematic and PCB layout

The schematic and PCB layout were completed using KiCAD 8. The design files are in the power-meter-pcb folder.

Code

The firmware is written to use the Arduino environment of Platform IO and is located in the power-meter-code directory.

Libraries

Install the following libraries, either by using the Arduino library manager or going to their GitHub repository and cloning them.

• ArduinoJson library for JSON encoding and decoding.
• ICM42670P library for communicating with the IMU.
• BasicLinearAlgebra library for matrix maths. This is also added as a submodule for testing the Kalman filter on a computer.
• ArduinoBLE library for Bluetooth Low Energy (BLE) communications.
• PubSubClient library for communicating using MQTT over WiFi.

Tools for updating dates of changed files and versions

A bash script has been written to update the dates on all modified or staged files (not including untracked files). To perform this operation, run:

./tools/update_date.sh

Another script is included to update the version info on all files and definitions for the code. The files and elements updated include:

• Any @version tags in the code directory.
• The VERSION definition in defines.h.
• The Doxygen version number in Doxyfile.

As an example:

./tools/update_version.sh 1.2.3

Git Hook for checking dates are correct before committing

This needs to be modified to work with the platform IO structure. Copy the pre-commit file into .git/hooks/pre-commit. This will check the date of code files and make sure they are up to date.

Doxygen documentation

Documentation can be automatically generated using Doxygen by running doxygen from the root folder of the repository. You might need to install doxygen and graphviz first. The output will be placed in the docs folder. GitHub actions may be set up later down the track to automatically generate and deploy to GitHub pages on commit- however that would require a public repository and documentation.

To generate a massive appendix for the report, run ./tools/generate_refman.sh

The output file will be refman.pdf.

Scripts and testing

Scripts for testing the board hardware and easing development of certain sections can be found in the scripts-testing directory. This includes python scripts used to log data over MQTT and plot it.