GPIO#

This project explores microcontroller analog and digital input and output by building a “kitchen scale” - with Bluetooth LE. Check also the MicroPython documentation for all available I/O functions.

../_images/scale_weights.jpg

Fig. 17 The completed “kitchen scale”#

Run the code in the next cell to download the code and instructions.

%%bash

cd $IOT_PROJECTS
svn checkout https://github.com/iot49/iot49.org/trunk/docs/projects/balance
Hide code cell output 
   C balance/app.ipynb
   C balance/ble.ipynb
   C balance/buttons.ipynb
   C balance/circuit.ipynb
   C balance/code.ipynb
   C balance/code
   A balance/code/lib
   A balance/code/lib/ble_advertising.py
   A balance/code/lib/ble_uart_peripheral.py
   A balance/code/lib/button.py
   A balance/code/lib/hx711.py
   A balance/code/lib/scale.py
   A balance/code/lib/scale_hx711.py
   A balance/code/lib/ssd1306.py
   A balance/code/main.py
   C balance/display.ipynb
   C balance/figures
   A balance/figures/acrylic.svg
   A balance/figures/bluefruit1.jpeg
   A balance/figures/bluefruit2.jpeg
   A balance/figures/bluefruit3.jpeg
   A balance/figures/circuit_diagram.svg
   A balance/figures/esp32_adc_vin.png
   A balance/figures/full_diagram.svg
   A balance/figures/huzzah32-pinout.png
   A balance/figures/ina126.png
   A balance/figures/load_cell.jpg
   A balance/figures/scale.jpg
   A balance/figures/scale_fat_strokes.svg
   A balance/figures/scale_side.jpg
   A balance/figures/scale_weights.jpg
   A balance/figures/sparkfun_loadcell.png
   C balance/hx711.ipynb
   C balance/parts.ipynb
   C balance/ticks.ipynb
Checked out revision 110.

Now the projects/balance folder contains the instructions. Open 01_parts.ipynb. Unlike the online instructions, this file is “live”, i.e. you can run the cells and make modifications.