Time to better understand Epaper or E-ink paper. At least for a project. Many of the E-readers use this display as it is stable, does not require power after updating and is mild for your eyes. So how does that work in practice and how does software and hardware work together.

I have downloaded the Waveshare code (version 2019-04-08), from https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT which relies on the BCM2835 library to connect to the hardware. I have used that BCM2835 library many times before as it is fast and stable.

The top level is demo software, just clears the screen and show some boxes etc.

The top level software that I have developed is making use of the underlying libraries and takes instructions from a user to position and display circles, lines etc.

A detailed document with the experience and description is epaper.odt

The program depends on the BCM2835 Library

Make your self superuser : sudo bash Install latest from BCM2835 from : http://www.airspayce.com/mikem/bcm2835/

1. wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.56.tar.gz
2. tar -zxf bcm2835-1.56.tar.gz // 1.56 was version number at the time of writing
3. cd bcm2835-1.56
4. ./configure
5. sudo make check
6. sudo make install

cd epaper To create the epaper executable : make To clean : make clean

note: you might can missing braces around initializer for font12CN and font24CN. Ignore those that is a known compiler error

The BCM2835 library needs to run as Root for the I2C communication to work.

sudo ./epaper -h will display help A detailed document with the experience and description is epaper.odt

• Initial version

• fixed compile issues on Raspberry Pi-OS (Buster)

• Paul van Haastrecht ([email protected])

This project is licensed under the GNU GENERAL PUBLIC LICENSE 3.0