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Mario Visic 7ac5141509 Reduce the CPU load when waiting for the display
In many places a `pass` instruction is used in loops to wait until we hear back
back from the display. This causes the loop to execute continuously which uses
all of the available CPU, if we instead sleep for 1ms, we don't lose much time
(less than 1ms each wait) and we dramatically reduce the load on the CPU.

Before the change (updating a 3-color 2.13" display):

```
time python3 ./update_display

real    0m19.664s
user    0m17.622s
sys     0m1.046s
```

After the change:

time python3 ./update_display

real    0m19.730s
user    0m3.563s
sys     0m0.792s1

The total time to run the script is about the same, but the CPU time has reduced dramatically.
2020-02-06 21:03:43 +11:00
.github/workflows update pylint examples directive 2020-01-14 17:15:23 -06:00
adafruit_epd Reduce the CPU load when waiting for the display 2020-02-06 21:03:43 +11:00
docs PyPi setup. 2018-08-04 12:01:46 -04:00
examples Added EPD Pillow Shapes and Text demo 2019-10-22 10:23:33 -07:00
.gitignore Moved repository from Travis to GitHub Actions 2020-01-04 14:17:32 -05:00
.pylintrc ignore the board module imports in .pylintrc 2018-08-25 14:07:42 +00:00
.readthedocs.yml Initial lib setup 2018-07-12 15:50:47 -04:00
CODE_OF_CONDUCT.md Initial lib setup 2018-07-12 15:50:47 -04:00
LICENSE Initial lib setup 2018-07-12 15:50:47 -04:00
README.rst Moved repository from Travis to GitHub Actions 2020-01-04 14:17:32 -05:00
requirements.txt Added Framebuf to requirements 2019-10-20 11:02:15 -07:00
setup.py Added Framebuf to requirements 2019-10-20 11:02:15 -07:00

Introduction
============

.. image:: https://readthedocs.org/projects/adafruit-circuitpython-epd/badge/?version=latest
    :target: https://circuitpython.readthedocs.io/projects/epd/en/latest/
    :alt: Documentation Status

.. image:: https://img.shields.io/discord/327254708534116352.svg
    :target: https://discord.gg/nBQh6qu
    :alt: Discord

.. image:: https://github.com/adafruit/Adafruit_CircuitPython_EPD/workflows/Build%20CI/badge.svg
    :target: https://github.com/adafruit/Adafruit_CircuitPython_EPD/actions/
    :alt: Build Status

This library is for using CircuitPython with e-ink displays with built in SRAM.

Dependencies
=============
This driver depends on:

* `Adafruit CircuitPython <https://github.com/adafruit/circuitpython>`_
* `Bus Device <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>`_
* `font5x8.bin found in the examples bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>`_

Please ensure all dependencies are available on the CircuitPython filesystem.
This is easily achieved by downloading
`the Adafruit library and driver bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>`_.

Installing from PyPI
====================

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally `from
PyPI <https://pypi.org/project/adafruit-circuitpython-epd/>`_. To install for current user:

.. code-block:: shell

    pip3 install adafruit-circuitpython-epd

To install system-wide (this may be required in some cases):

.. code-block:: shell

    sudo pip3 install adafruit-circuitpython-epd

To install in a virtual environment in your current project:

.. code-block:: shell

    mkdir project-name && cd project-name
    python3 -m venv .env
    source .env/bin/activate
    pip3 install adafruit-circuitpython-epd

Usage Example
=============

.. code-block:: python

    import digitalio
    import busio
    import board
    from adafruit_epd.epd import Adafruit_EPD
    from adafruit_epd.il0373 import Adafruit_IL0373

    # create the spi device and pins we will need
    spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
    ecs = digitalio.DigitalInOut(board.D12)
    dc = digitalio.DigitalInOut(board.D11)
    srcs = digitalio.DigitalInOut(board.D10)    # can be None to use internal memory
    rst = digitalio.DigitalInOut(board.D9)    # can be None to not use this pin
    busy = digitalio.DigitalInOut(board.D5)   # can be None to not use this pin

    # give them all to our driver
    print("Creating display")
    display = Adafruit_IL0373(104, 212, spi,          # 2.13" Tri-color display
                              cs_pin=ecs, dc_pin=dc, sramcs_pin=srcs,
                              rst_pin=rst, busy_pin=busy)

    display.rotation = 1

    # clear the buffer
    print("Clear buffer")
    display.fill(Adafruit_EPD.WHITE)
    display.pixel(10, 100, Adafruit_EPD.BLACK)

    print("Draw Rectangles")
    display.fill_rect(5, 5, 10, 10, Adafruit_EPD.RED)
    display.rect(0, 0, 20, 30, Adafruit_EPD.BLACK)

    print("Draw lines")
    display.line(0, 0, display.width-1, display.height-1, Adafruit_EPD.BLACK)
    display.line(0, display.height-1, display.width-1, 0, Adafruit_EPD.RED)

    print("Draw text")
    display.text('hello world', 25, 10, Adafruit_EPD.BLACK)
    display.display()


Contributing
============

Contributions are welcome! Please read our `Code of Conduct
<https://github.com/adafruit/Adafruit_CircuitPython_EPD/blob/master/CODE_OF_CONDUCT.md>`_
before contributing to help this project stay welcoming.

Documentation
=============

For information on building library documentation, please check out `this guide <https://learn.adafruit.com/creating-and-sharing-a-circuitpython-library/sharing-our-docs-on-readthedocs#sphinx-5-1>`_.