Master thesis project - "Step estimation from motion sensors" with RPi Pico W

Overview

The aim of this project is to create a circuit to measure and analyse the data from two different IMUs (Inertial Measurement Units) to determine the accuracy of the step estimation algorithm (multiple if there is time).

Required / used components

The project will make use of a variety of components:

• Raspberry Pi Pico W (access point, web server, reading sensors, driving TFT display) running MicroPython with various CircuitPython Libraries,
• Pico-10DOF-IMU as the first IMU,
• ST-9-DOF-Combo as the second IMU,
• Pico-UPS-B as a power source,
• 3.5inch_TFT_Touch_Shield to display the measurements and battery level,
• Pico-Dual-Expander to hold some components together w/o soldering,
• 3D printed enclosure for the device to protect the circuit (custom design).

How to connect the components

Simple list of connections in ~/.BACKUP/project_circuit_simple_diagram.pdf

Project structure and important locations

This project consists of many files and directories, the most important of which are described below:

• Directory ~/.BACKUP/ containing the backup and important files that should not be transferred to the Pico:
  • Adding the CircuitPython compatibility layer - short tutorial in ~/.BACKUP/adafiut_libs/README.md (with required libraries in the same directory),
  • Raspberry Pi Pico W board pinout in ~/.BACKUP/pico-pinout.svg,
  • Firmware used in the project in ~/.BACKUP/RPI_PICO-20240602-v1.23.0.uf2,
  • ~/.BACKUP/code/ for old / sample / backup code,
  • (LINUX USERS: MicroPico Extension for VSCode) script used to resolve user permissions in ~/.BACKUP/solvePermissions.sh,
• ~/classes/ directory containing all necessary classes for easy development,
• ~/lib/ directory containing all the CircuitPython libraries that may be needed in the project,
• ~/src/ directory contains all the resources needed for the web server,
• main.py as the main file of the project and the program to be executed on startup.

Progress

First major success:

I managed to create an asynchronous web server that handles clients and reads sensor data at the same time (based on a scheduler, multithreading-coming-soon™). Notable achievements of this release:

• Pico acting as an access point,
• Handling of asynchronous requests,
• Added translation layer for CircuitPython,
• Reading IMU sensor data using the CircuitPython library (Adafruit "LSM6DSOX + LIS3MDL 9 DoF" Sensor),
• Control the device from a web page,
• Live UI update and synchronous data retrieval.