The examples in this guide are no longer supported. Please check out the Adafruit eInk Display Breakouts guide for CircuitPython and Python usage: https://learn.adafruit.com/adafruit-eink-display-breakouts
Compiling
These test programs should compile with no additional libraries, but the EPD driver needs the fuse development library installed. And a few examples make us of the Python Imaging Library (PIL)sudo apt-get install libfuse-dev python-imaging # For the Twitter Demo sudo apt-get install python-setuptools sudo easy_install pip git clone https://github.com/repaper/gratis.git cd gratis/PlatformWithOS make rpi sudo make rpi-install
sudo opkg install libfuse-dev python-imaging # For the Twitter demo opkg install python-pip python-setuptools # Extra item for BeagleBone # The program uses device tree files to access the GPIOs git clone https://github.com/nomel/beaglebone.git cp -p beaglebone/gpio-header/generated/gpio-P9.* /lib/firmware git clone https://github.com/repaper/gratis.git cd gratis/PlatformWithOS make bb sudo make bb-install
File Read/Write Description
-------- ----------- ---------------------------------
version Read Only The driver version number
panel Read Only String describing the panel and giving
its pixel width and height
current Read Only Binary image that matches the currently
displayed image (big endian)
display Read Write Image being assembled for next display
(big endian)
temperature Read Write Set this to the current temperature in Celsius
command Write Only Execute display operation
BE Directory Big endian version of current and display
LE Directory Little endian version of current and display
Command Byte Description
-------- ----- --------------------------------
'C' 0x43 Clear the EPD, set `current` to all zeros, `display`
is not affected
'U' 0x5A Erase `current` from EPD, output `display` to EPD,
copy display to `current`
Notes:
- The default bit ordering for the display is big endian i.e. the top left pixel is the value 0x80 in the first byte.
- The `BE` directory is the same as the root `current` and `display`.
- The `LE` directory `current` and `display` reference the top left pixel as 0x01in the first byte.
- The `current_inverse` and `display_inverse` represent black as zero (0) and white as one (1) while those item without the suffix represent the display's natural coding (0=>white, 1=>black)
- The particular combination of `BE/display_inverse` is used in the Python EPD demo since it fits better with the Imaging library used.
Set Panel Size in FUSE Configuration
cat /etc/default/epd-fuse
Expected Output:
# Default settings for epd-fuse file is sourced by /bin/sh from # /etc/init.d/epd-fuse # Options to pass to epd_fuse #EPD_MOUNTPOINT=/dev/epd #EPD_SIZE=2.0 #EPD_OPTS=
Note: All the configurations are commented out and represent the default settings. If your panel is NOT the 2.0", then you must change this configuration.
How to edit the configuration file:
How to edit the configuration file:
sudo nano /etc/default/epd-fuse
Uncomment the EPD_SIZE and change the value to your panel size (either 2.7 or 1.44). Save and exit.
Start the Driver
sudo service epd-fuse start cat /dev/epd/panel
Expected Output for a 2.7" panel:
EPD 2.7 264x176
python demo/DrawDemo.py
Nothing happening on the screen? You may have a "COG 2" version of the display. See the FAQ page!
Image demo
- Accepts a lists of image files on the command line.
- Converts them to grey scale to ensure formats like PNG, JPEG and GIF will work.
- Inverts the image since the E-Ink panel is reverse (i.e. black on white).
- Converts image to single bit (PIL "1" mode).
- Display the middle of the image (using crop function).
- Delay.
- Display the re-sized image.
- Delay before fetching next file.
Note: if scratch is installed on the system, the following commands will show some cartoon animals. The images when re-sized will be distorted if the aspect ration of the original image is not the same as the display.
python demo/ImageDemo.py /usr/share/scratch/Media/Costumes/Animals/cat* python demo/ImageDemo.py /usr/share/scratch/Media/Costumes/Animals/d*.png
Twitter Demo
Setup easy_install and use it to get pip, then use pip to get tweepy. Copy the sample configuration an edit to include your authentication information. Rather than using the basic authentication it is better to set up a Twitter App and generate a token for this. The token generation is quick atUse Ctrl-C to stop this program.
sudo pip install tweepy # setup the config cp demo/tweepy_auth.py-SAMPLE demo/tweepy_auth.py # *** edit the config nano demo/tweepy_auth.py # run the demo (this watches for linux) python demo/TwitterDemo.py linux
Partial Demo
Display random overlapping rectangles using partial update. First argument is number of rectangle to generate before updating the EPD, second number is the number of frames to display before the program exits.
python demo/PartialDemo.py 3 20
Counter Demo
Display a 4 digit hex counter uses partial update to only change the updated digits. This will look somewhat strange as the display inversion will make the counter appear to go through a sequence like: 0000 0001 0000 0001 ...delay... 0001 0002 0001 0002
Use Ctrl-C to stop this program.
python demo/CounterDemo.py 3 20
Page last edited March 08, 2024
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