Check-y

This project was completed as part of the Chinese Hardware Innovation Camp (CHIC) program, a Master's minor at the Swiss Federal Institute of Technologly in Lausanne (EPFL), Switzerland.

Table of Contents

• Description
• App screenshots
• Tech/frameworks used
• Hardware needed
• Setup
• How to use our device
• Sources
• Authors
• License

Description

The main goal of this device is to detect large head impacts sustained by athletes. An alert is displayed by the app when the acceleration is considered dangerous and may require an examination of the player.

The project can be broken down into 4 modules. The features detailed in the schematic below have all been successfully implemented.

App screenshots

Through the app, the user can:

• connect to the router (via BlueTooth)
• receive data from a headband (via the router)
• read live linear & angular accelerations
• plot these accelerations during a chosen time period
• define his / her safety threshold
• receive an alert when the acceleration exceeds the defined threshold
• download the received data as a CSV file

Tech/frameworks used

To develop this product, we used:

• the Arduino IDE to code the firmware in C++
• the Flutter framework to develop a cross-platform app
• EasyEDA to design our custom PCB for the headband
• Django and Python to build our mySQL database and Bootstrap for the database frontend
• Google Cloud to migrate ou database online

Hardware needed

• an ESP32 board (e.g., a DO IT ESP32 DEVKIT V1 board) for the router
• our custom PCB for the headband (cf. the "Hardware" folder )
• a tablet or smartphone to run the Flutter app (⚠️ the app has only been tested on Android)

Setup

In order to execute and upload properly the firmware to a router or a headband, you must first make sure that the Arduino IDE has been correctly setup:

1. install the Arduino IDE
2. install the ESP32 board module (procedure)
3. for the router, choose Tools > Board > ESP32 Arduino > WEMOS LOLIN32 (important to be able to change the “Partition Scheme” (also in Tools) to “No OTA (Large APP)”
4. for the router, choose Tools > Board > ESP32 Arduino > DO IT ESP32 DEVKIT V1
5. ⚠️ add our two custom libraries (Adafruit LIS331 & Bolder Flight Systems BMI088 in the Firmware > "Custom Libraries" folder) using Arduino > Sketch > Include Library > Add .ZIP Library
6. add the “Adafruit BusIO” and “Adafruit Unified Sensor” libraries using Arduino > Tools > Manage Libraries

Once the Arduino IDE is correctly setup:

1. load the headband firmware onto our custom PCB
2. place the PCB inside the headband
3. load the router firmware onto an ESP32 board (we used a DO IT ESP32 DEVKIT V1 board)
4. download the app on a tablet / smartphone

How to use our device

To send the measured accelerations from the headband to the tablet:

1. turn on the router (press the button once)
2. wait a second
3. turn on the headband (using the switch)
4. open the app on the tablet
5. click on the expandable menu at the bottom right of the app
6. click on "Bluetooth scan"
7. a new window should have opened displaying the detected BLE devices → select "Check-y router"

After approximately 7 seconds, the live accelerations should be displayed on the app.

Sources

We used Chase Strickler's hear rate app (GitHub) as a starting point for our own app.

Authors

🧑🏻‍🏭 Taavet Kangur (in charge of the hardware development)
👩🏼‍💻 Diane Marquette (in charge of the firmware and app development)
🧑🏾‍💻 Maëlick Brochut (in charge of the signal processing and back-end)
👩🏻‍🎨 Marine Fondin (in charge of the headband design)
💵 Nicolas Mauroux (the business guy)

License