leaf-notes

An application that generates information to be displayed on a small e-ink screen attached to a Raspberry Pi Zero 2 W.

Provided as a Docker image, that through SPI / GPIO controls an e-ink screen.

Hardware

• Raspberry Pi Zero 2 W
• Waveshare e-ink display
  • https://www.waveshare.com/wiki/2.13inch_e-Paper_HAT_(B)
  • Specs:
    • Colour: Black / Red / White
    • Resolution: 212x104
  • Revision: 2.1 V3

Getting started

Create and activate virtual environment for packages

python3 -m venv .venv
source .venv/bin/activate

Deactivate virtual environment

deactivate

Running the program

python -m notes Notes module generates notes and saves these as images

usage: python -m notes [-h] [-v | -q] --quotes-path path --weather-latitude degrees --weather-longitude degrees --weather-altitude height [-u] [-r degrees]

Generates leaf-note as images

optional arguments:
  -h, --help            show this help message and exit
  -v, --verbose         increase output verbosity
  -q, --quiet           decrease verbosity to absolute minimum
  --quotes-path path    Path to yaml file with Quote definitions
  --weather-latitude degrees
                        Latitude for weather information
  --weather-longitude degrees
                        Longitude for weather information
  --weather-altitude height
                        Height above sea level in meters
  -u, --update-display  Invoke display module to also update the display
  -r degrees, --rotate degrees
                        Rotate image a number of degrees, defaults to 0

python -m display Display module can clear display and render images to display

usage: python -m display [-h] [-v | -q] {clear,render} ...

Handles redering to an e-paper display over SPI on a Raspberry Pi

positional arguments:
  {clear,render}  A command must be specified
    clear         Clear the screen
    render        Render images to screen (clears before rendering)

optional arguments:
  -h, --help      show this help message and exit
  -v, --verbose   increase output verbosity
  -q, --quiet     decrease verbosity to absolute minimum

python -m display render Render command options

usage: python -m display render [-h] -b path -c path [-r degrees]

optional arguments:
  -h, --help            show this help message and exit
  -b path, --black-image path
                        Path to black part of image, required
  -c path, --colour-image path
                        Path to color part of image, required
  -r degrees, --rotate degrees
                        Rotate image a number of degrees, defaults to 0

Running the program as a Docker container

Pull image

docker pull ghcr.io/rasmuslp/leaf-notes:<version>

Run a one-time container.
Access to gpiochip0 and spidev0.0 is required to communicate with the display. Quotes file needs to be mounted into the container.

docker run -it --rm \
	--device /dev/gpiochip0 \
	--device /dev/spidev0.0 \
	-v /path-to/quotes.yml:/usr/src/app/quotes.yml:ro \
	-e QUOTES_PATH=quotes.yml \
	-e WEATHER_LATITUDE=50 \
	-e WEATHER_LONGITUDE=10 \
	-e WEATHER_ALTITUDE=10 \
	-e UPDATE_DISPLAY=1 \
	--name leaf-notes \
	ghcr.io/rasmuslp/leaf-notes:<version> python -m notes

Options can be set with environment variables

ENV VAR	Name	Required
VERBOSE	verbose
QUIET	quiet
QUOTES_PATH	quotes-path	Yes
WEATHER_LATITUDE	weather-latitude	Yes
WEATHER_LONGITUDE	weather-longitude	Yes
WEATHER_ALTITUDE	weather-altitude
UPDATE_DISPLAY	update-display
ROTATE	rotate

Upgrading packages

make upgrade-deps

Projects used

• https://github.com/waveshare/e-Paper - eInk display interface
  • This installs deps for Jetson!
    • https://github.com/waveshare/e-Paper/blob/master/RaspberryPi_JetsonNano/python/setup.py
  • Consider https://github.com/txoof/epdlib ??? - Requires spidev and RPi.GPIO, which cant install on mac....
• https://github.com/yaml/pyyaml/ - Yaml loader / (de)serializer
  • https://pyyaml.org/wiki/PyYAMLDocumentation
• https://github.com/dbader/schedule - Scheduler
  • https://pypi.org/project/schedule/
  • https://schedule.readthedocs.io/en/stable/
• https://github.com/PyCQA/pylint - Tooling
  • List of builtin rules: http://pylint.pycqa.org/en/latest/technical_reference/features.html
  • pylint --generate-rcfile | less to generate a rules reference
• https://github.com/astral-sh/ruff - Tooling
• https://github.com/adrienverge/yamllint - Tooling

Docker

Build for development

docker build -t leaf-notes:local-development -f dev.dockerfile .

Build for production

docker build -t leaf-notes:local .

Notes

venv in Docker
https://medium.com/@elhayefrat/virtualenv-inside-docker-ab26f63ce6d1

Set unbuffered to ensure all logs from Python are delivered to container std our / err
https://docs.python.org/3/using/cmdline.html#envvar-PYTHONUNBUFFERED

Dependencies for Pillow
See list of external dependencies here https://pillow.readthedocs.io/en/latest/installation.html#external-libraries
See Docker Debian Buster example here https://github.com/python-pillow/docker-images/blob/master/debian-10-buster-x86/Dockerfile