Fitness tracker with breathing assistant

A heart rate based breathing guiding system to help regulate the heart beat through controlled breathing exercises with features for timing and hydration.

info

Author: Mihon Corina-Cristiana
GitHub Project Link: https://github.com/UPB-PMRust-Students/project-Corina-Mihon

Description

This project is a fitness tracker with a guided breathing assistant. It measures heart rate through a pulse sensor, displays real-time data on a screen, and guides users with visual breathing exercises using an LED indicator. If the rate is too high, an LED pulses in a rhythm that guides the user to breath in and out slowly. The device also includes features for hydration tracking, workout timing, making it a compact welness tool.

Motivation

I chose this project because of the increasing importance of stress management and heart health. By combining heart rate monitoring with breathing exercises, users can make adjustments to improve their physical health. It is a way of integrating technology into wellness practices.

Architecture

The main controller reads physiological data from the pulse sensor and controls an LED for visual breathing guidance. A button connected to the microcontroller allows the user to scroll through the menus (pulse reading, timin, hydration) and a second button allows the users to chose the menu or other settings. The display, also connected to the microcontroller, shows the data. The second microcontroller handles debugging.

Log

Week 5 - 11 May

I connected the main Raspberry Pi Pico 2W with the second one that I use as a debbuger. I also connected the pulse sensor and implemented the basic pulse reading functionality and after that I displayed the measured BPM on the screen.

Week 12 - 18 May

I displayed on the screen the menu for the mode(either exercising or relaxing). I connected the LEd module and added LED feedback to guide breathing during abnormal BPM, implemented PWM for light transitions and added the button to select the mode.

Week 19 - 25 May

I worked at the way the project looks like and I have improved the pulse reading functionality with the logic given by an AI chat.

Hardware

Raspberry Pi Pico 2W: main controller for handling sensor data, controlling the LED

Raspberry Pi Pico 2W: used for debugging

XD-58C pulse sensor: measure the user's heart rate

RBG LED: used for the visual breathing feedback

Button(mode): allows the user to switch between menus

Button(action): allows the user to make choices

1.44'' LCD Display: Displays the heart rate

Schematics

Bill of Materials

Device	Usage	Price
Raspberry Pi Pico 2W	The microcontroller	39.66 RON x 2
XD-58C pulse sensor	The pulse sensor	15.17 RON
1.44'' LCD Module	Display	28 RON
Button	Press the button to select modes	2 RON
Button	Press the button to scroll	2 RON
RGB LED module	LED light	5 RON

Software

Library	Description	Usage
embedded-graphics	2D graphics library	Used for drawing text to the display
embassy_embedded_hal	Adapters between Embassy and the standard embedded-hal traits	With shared_bus::blocking::spi::SpiDevice safely shares SPI between display and other peripherals.
embassy_executor	The async runtime provided by Embassy for embedded systems	Runs async tasks such as #[embassy_executor::main] and the breathing LED task
embassy_time	Provides async-friendly time utilities like timers, delays, and durations	Used for Timer::after, Duration, Instant
defmt	Compact and efficient logging system for embedded devices	Used for logging/debugging with info!
panic_probe	Handles panics	Reports detailed panic messages during runtime
embassy_rp	The embassy hal	Used to access and control the Raspberry Pi Pico W hardware, including GPIOs, ADC, SPI, PWM, and system initialization via init
embassy_sync	Provides synchronization primitives for async and sync use	Used to run async code on embedded systems
mipidsi	Display driver for ST7735 TFT displays	Used to control SPI-based LCD displays like ST7735s

Links

1. Projects 2023
2. link ...