«DiY» WePosture#

Good posture through equilibrium. WIP - Work-In-Progress

Let’s tinker gadgets

Time estimate: One afternoon (net)
Cost estimate: Far below 50 Euro (Raspberry Pi, Monitor, Keyboard, Mouse not included)
Skill level: Intermediate hobby tinkerer

Background#

Recently I met a physician in the field of orthopaedics, sports medicine and performance diagnostics. I learned from him that a good posture is important for our health and well-being. So let’s create some thing!

The Gadget#

With a …

home-made Balance Board (like a Wii Balance Board) with hardware used in digital scales, voltage amplifiers (HX711)
a (little) oversized microcontroller, Raspberry PI 5 (RPI5), we can directly work on, so a full-blown computer.
WebApp (Full-Stack with FARM-Stack: FastAPI, React, MongoDB) to visualize the data and to provide a user interface for the user to interact with the gadget. In the DataBase historical health data can be stored and analyzed.

BOM - Bill Of Material#

Production (and Development):

1x Raspberry PI 5 (RPI5)
1x SD-Card 32G
1x Power adapter 5V, enough current for powering RPI5
1x USB-C cable for powering RPI5
1x Breadboard 830 points
T-Cobbler for RPI
Enough Jumper wires male-male
Enough Jumper wires male-female
1x Ebay: Digital Scale Set (4x Load Cell 50kg each, 1x Amplifier HX711)
3x Ebay: Amplifier HX711
4x Thingiverse| Half Bridge Load Sensor mount

Development (in addition):

1x Adapter HDMI-D-plug to HDMI-A-Socket
1x Monitor
1x Keyboard
1x Mouse

SBOM - Software Bill Of Material#

Production (and Development):

Raspberry Pi OS with desktop and recommended software (64-bit) Release date: July 4th 2024, Kernel version 6.6, Debian version: 12 (bookworm)
Python 3 12.5
hx711-multi 1.4.1

Development (in addition):

Visual Studio Code 1.92.2
pipx 1.1.0
Poetry 1.8.3

Resources#

Sketches#

Here some sketches:

../../_images/board_with_feed_and_loadcells.png

Expert Dialogs#

Here some GPT-4o chats:

Related GPT-4o chats

Insights in Work-In-Progress#

../../_images/balance_board.png — Balance board with top side made of glass waiting and 1k Resistors waiting to get to the four HX711 amplifiers of in the circuit.#

../../_images/sketch_ui_ux.png — Sketch on UI/UX#

../../_images/rpi_4b_and_circuit.png — RPI 4B connected to 2x4 HX711, Power, Monitor, Keyboard and Mouse#

../../_images/pinout_connections_1_of_2.png — Pinout connections 1 of 2#

../../_images/pinout_connections_2_of_2.png — Pinout connections 2 of 2#

Software (Repository: basejumpa/WeBalance ) already acquires data. Here the continuous output (obsolete, still the output of just 4 load cells connected):

--snip--

read duration: 0.969 seconds, rate: 10.3 Hz
raw ['1990.750', '-28956.286', '-1740.286', '-17075.444']
wt ['1990.750', '-28956.286', '-1740.286', '-17075.444']

read duration: 0.968 seconds, rate: 10.3 Hz
raw ['1995.625', '-28946.571', '-1719.857', '-17096.286']
wt ['1995.625', '-28946.571', '-1719.857', '-17096.286']

read duration: 0.978 seconds, rate: 10.2 Hz
raw ['1998.714', '-28930.429', '-1654.143', '-17004.875']
wt ['1998.714', '-28930.429', '-1654.143', '-17004.875']

--snap--