Easy e-paper finally comes to microcontrollers with these breakouts and shields that are designed to make it a breeze to add a tri-color eInk display. Chances are you've seen one of those new-fangled 'e-readers' like the Kindle or Nook. They have gigantic electronic paper 'static' displays - that means the image stays on the display even when power is completely disconnected. The image is also high contrast and very daylight readable. It really does look just like printed paper!

Adafruit has liked these displays for a long time, but they were never designed for makers to use. Finally, we decided to make our own!

We have a couple of 2.7" EPD displays:

Using an Adafruit Arduino library, you can create a 'frame buffer' with what pixels you want to have activated and then write that out to the display. Most simple breakouts leave it at that. But if you do the math, 264 x 176 pixels x 2 colors = 11.5 KBytes. Which won't fit into many microcontroller memories. Heck, even if you do have 32KB of RAM or more, why waste 12KB?

So we did you a favor and tossed a small SRAM chip on the back. This chip shares the SPI port the eInk display uses, so you only need one extra pin. And, no more frame-buffering! You can use the SRAM to set up whatever you want to display, then shuffle data from SRAM to eInk when you're ready. The library Adafruit has does all the work for you, you can just interface with it as if it were an Adafruit_GFX compatible display.

For ultra-low power usages, the onboard 3.3V regulator has the Enable pin brought out so you can shut down the power to the SRAM, MicroSD and display.

There is even an added MicroSD socket on the breakouts and FeatherWings, so you can store images, text files, whatever you like to display. Everything is 3 or 5V logic safe, so you can use it with any and all common Maker microcontrollers.

This e-Paper display uses SPI to receive image data. Since the display is SPI, it was easy to add two more SPI devices to share the bus - an SPI SRAM chip and SPI-driven SD card holder. There are quite a few pins and a variety of possible combinations for control depending on your needs

The pinouts are identical for the 2.13" and 2.7" E-Ink display!

Power Pins

  • 3-5V / Vin - this is the power pin, connect to 3-5VDC - it has reverse polarity protection but try to wire it right!
  • 3.3V out - this is the 3.3V output from the onboard regulator, you can 'borrow' about 100mA if you need to power some other 3.3V logic devices
  • GND - this is the power and signal ground pin
  • ENAble - This pin is all the way on the right. It is connected to the enable pin on the onboard regulator that powers everything. If you want to really have the lowest possible power draw, pull this pin low! Note that if you do so, you will cut power to the eInk display AND also the SPI RAM (thus erasing it) and the SD card (which means you'll have to re-initialize it when you re-power things.

Data Control Pins

  • SCK - this is the SPI clock input pin, required for e-Ink, SRAM and SD card
  • MISO - this is the SPI Microcontroller In Serial Out pin, its used for the SD card and SRAM. It isn't used for the e-Ink display which is write-only, however you'll likely be using the SRAM to buffer the display so connect this one too!
  • MOSI - this is the SPI Microcontroller Out Serial In pin, it is used to send data from the microcontroller to the SD card, SRAM and e-Ink display
  • ECS - this is the E-Ink Chip Select, required for controlling the display
  • D/C - this is the e-Ink Data/Command pin, required for controlling the display
  • SRCS - this is the SRAM Chip Select, required for communicating with the onboard RAM chip.
  • SDCS - this is the SD card Chip Select, required for communicating with the onboard SD card holder. You can leave this disconnected if you aren't going to access SD cards
  • RST - this is the E-Ink ReSeT pin, you may be able to share this with your microcontroller reset pin but if you can, connect it to a digital pin.
  • BUSY - this is the e-Ink busy detect pin, and is optional if you don't want to connect the pin (in which case the code will just wait an approximate number of seconds).

Assembly

Cut the header down to length if necessary. It will be easier to solder if you insert it into a breadboard - long pins down

Add the E-Ink Display

 

Place the board over the pins so that the short pins poke through the top of the breakout pads

And Solder!

 

Be sure to solder all pins for reliable electrical contact.

(For tips on soldering, be sure to check out the Guide to Excellent Soldering).

OK, you're done!

Breakout Wiring

Though it looks like a lot of connections, wiring up an eInk breakout is pretty straightforward! Below shows using hardware SPI to connect it to an Adafruit Metro M4.

  • Vin connects to the microcontroller board's 5V or 3.3V power supply pin.
  • GND connects to ground.
  • CLK connects to SPI clock. It's easiest to connect it to pin 3 of the ICSP header.
  • MOSI connects to SPI MOSI. It's easiest to connect it to pin 4 of the ICSP header.
  • MISO connects to SPI MISO. It's easiest to connect it to pin 1 of the ICSP header.
  • ECS connects to our e-Ink Chip Select pin. We'll be using Digital 9.
  • D/C connects to our e-Ink data/command select pin. We'll be using Digital 10.
  • SRCS connects to our SRAM Chip Select pin. We'll be using Digital 6.
  • RST connects to our e-Ink reset pin. We'll be using Digital 8.
  • BUSY connects to our e-Ink busy pin. We'll be using Digital 7.
  • SDCS connects to our SD Card Chip Select pin. We'll be using Digital 5.

Python Wiring

There are many Single Board Computers (SBC) so showing them all is impractical. The Raspberry Pi is the most common and it is shown below. Others are likely similar. The SPI peripheral may need to be enabled on such boards.

  • Raspberry Pi 3.3 to display VIN
  • Raspberry Pi GND to display GND
  • Raspberry Pi SCLK to display SCK
  • Raspberry Pi MOSI to display MOSI
  • Raspberry Pi GPIO CE0 to display ECS
  • Raspberry Pi GPIO 22 to display D/C
  • Raspberry Pi GPIO 27 to display RST
  • Raspberry Pi GPIO 17 to display BUSY

One thing to remember with these small e-Ink screens is that its very slow compared to OLEDs, TFTs, or even 'memory displays'. It will take may seconds to fully erase and replace an image

There's also a recommended limit on refeshing - you shouldn't refresh or change the display more than every 3 minutes (180 seconds).

You don't have to refresh often, but with tri-color displays, the larger red ink dots will slowly rise, turning the display pinkish instead of white background. To keep the background color clear and pale, refresh once a day

Do not update more than once every 180 seconds or you may permanently damage the display

To use the display, you will need to install the Adafruit_EPD library (code on our github repository). It is available from the Arduino library manager so we recommend using that.

From the IDE open up the library manager...

And type in adafruit EPD to locate the library. Click Install

If you would like to draw bitmaps, do the same with adafruit ImageReader, click Install

Do the same to install the latest adafruit GFX library, click Install

If using an earlier version of the Arduino IDE (pre-1.8.10), locate and install Adafruit_BusIO (newer versions handle this prerequisite automatically).

Check carefully to make sure you are running the right example and creating the matching ThinkInk type for your display or you won't see anything happen on the EPD (or the image may be really weird looking).

2.7" Tri-Color 264x176 Pixel Display

For the 264x176 Tri-Color displays, below is a tri-color demo.

Angled shot of a Adafruit 2.7" Tri-Color eInk / ePaper Display with SRAM - Red Black White.
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Top down view of a Adafruit 2.7" Tri-Color eInk / ePaper Shield with SRAM - Red Black White.
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The demo updates every 15 seconds, which is fine for demonstrating the functionality for a short time. NOTE it is recommend not to update more often than 180 seconds if you are planning on running any code long term to protect the display.

Open up FileExamplesAdafruit_EPD→ThinkInk_tricolor

Configure Pins

No matter what display you have, you will need to verify that your pins match your wiring. At the top of the sketch find the lines that look like:

#define EPD_DC      10
#define EPD_CS      9
#define SRAM_CS     6
#define EPD_RESET   8 // can set to -1 and share with microcontroller Reset!
#define EPD_BUSY    7 // can set to -1 to not use a pin (will wait a fixed delay)

If you wired the display differently than on the wiring page, adjust the pin numbers accordingly.

Shield Configuration

For the shield, since the pins are fixed, you can just use these settings:

#define EPD_DC      9
#define EPD_CS      10
#define SRAM_CS     8
#define EPD_RESET   -1
#define EPD_BUSY    -1

Configure Display Type & Size

Find the part of the script where you can pick which display is going to be used. The eInk displays are made up a combination of a Chipset and a Film in different sizes. Adafruit has narrowed it down to just a few choices between the size of the display, chipset, and film based on available combinations. In the sketch, it is sorted by size, so it's easy to find your display.

For either type of display, you will use the ThinkInk_270_Tricolor_C44 display initializer.

Just uncomment this line, and comment out any other line that is creating a ThinkInk display object

// 2.7" Tricolor Featherwing or Breakout with IL91874 chipset
//ThinkInk_270_Tricolor_C44 display(EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY);

Upload Sketch

After checking the pinouts and the display type one more time, go ahead and upload the sketch to your board. Once it is done uploading, open the Serial Monitor.

The display should start running a series of display tests

Not only can you draw shapes but you can also load images from the SD card, perfect for static images!

Tri-Color Display Demo

The Tri-color demo uses a single bitmap. The Blinka bitmaps below is used for the demonstration. Select the one that is correct for your display:

Download the blinka.bmp file and place it into the base directory of a microSD card and insert it into the microSD socket in the breakout.

Plug the MicroSD card into the display. You may want to try the SD library examples before continuing, especially one that lists all the files on the SD card

Open the file→examples→Adafruit_ImageReader→ThinkInkDisplays example

There are just a couple of things you may need to change in this file.

You will need to change your initializer to use ThinkInk_270_Tricolor_C44.

If you are using the shield, use these pin configurations:

#define EPD_DC      9
#define EPD_CS      10
#define SRAM_CS     8
#define EPD_RESET   -1
#define EPD_BUSY    -1
#define SD_CS       5

Upload to your board and you should see an image of Blinka appear.

If you want to later use your own image, use an image editing tool and crop your image to no larger than 264 pixels wide and 176 pixels high. Save it as a 24-bit color BMP file - it must be 24-bit color format to work, even if it was originally a 16-bit color image - because of the way BMPs are stored and displayed!

Check carefully to make sure you are running the right example and creating the matching library type for your display or you won't see anything happen on the EPD (or the image may be really weird looking).

CircuitPython eInk displayio Library Installation

To use displayio, you will need to install the appropriate library for your display. 

First make sure you are running the latest version of Adafruit CircuitPython for your board. You will need the latest version of CircuitPython.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle.  The introduction guide has a great page on how to install the library bundle for both Express and non-Express boards.

You will need to copy the appropriate displayio driver from the bundle lib folder to a lib folder on your CIRCUITPY drive. The displayio driver contains the initialization codes specific to your display that are needed to for it to work. Since there is more than one driver, you will need to copy the correct file over. Here is a list of each of the displays and the correct driver for that display.

To use the eInk displays with displayio, you will need to use the latest version of CircuitPython and a board that can fit `displayio`. See the Support Matrix to determine if `displayio` is available on a given board: https://circuitpython.readthedocs.io/en/latest/shared-bindings/support_matrix.html

Adafruit_CircuitPython_IL91874

The 2.7" Tri-Color displays use the Adafruit_CircuitPython_IL91874 library. To easily get all the required files and libraries, you can click the Download Project Bundle link at the top of the appropriate example code below. Just unzip, open the folder that corresponds to the version of CircuitPython you have installed, and copy the contents to the CIRCUITPY drive.

Angled shot of a Adafruit 2.7" Tri-Color eInk / ePaper Display with SRAM - Red Black White.
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Top down view of a Adafruit 2.7" Tri-Color eInk / ePaper Shield with SRAM - Red Black White.
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Image File

To show you how to use the eInk with displayio, below shows you how to draw a bitmap onto it. First start by downloading display-ruler.bmp

Copy display-ruler.bmp into the root directory of your CIRCUITPY drive.

Tri-Color Display Usage

2.7" 264x176 HD Tri-Color Breakout and Shield

In the examples folder for your IL91874 displayio driver, there should be a test for your display which we have listed here:

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

"""
  Simple test script for 2.7" 264x176 Tri-Color display shield
  Supported products:
  * Adafruit 2.7" Tri-Color ePaper Display Shield
    https://www.adafruit.com/product/4229

  This program only requires the adafruit_il91874 library in /lib
  for CircuitPython 5.0 and above which has displayio support.
"""

import time
import board
import displayio
import adafruit_il91874

# Used to ensure the display is free in CircuitPython
displayio.release_displays()

# Define the pins needed for display use on the Metro
spi = board.SPI()
epd_cs = board.D10
epd_dc = board.D9
epd_reset = board.D5
epd_busy = board.D6

# Create the displayio connection to the display pins
display_bus = displayio.FourWire(
    spi, command=epd_dc, chip_select=epd_cs, reset=epd_reset, baudrate=1000000
)
time.sleep(1)  # Wait a bit

# Create the display object - the third color is red (0xff0000)
display = adafruit_il91874.IL91874(
    display_bus,
    width=264,
    height=176,
    busy_pin=epd_busy,
    highlight_color=0xFF0000,
    rotation=90,
)

# Create a display group for our screen objects
g = displayio.Group()

# Display a ruler graphic from the root directory of the CIRCUITPY drive
with open("/display-ruler.bmp", "rb") as f:
    pic = displayio.OnDiskBitmap(f)
    # Create a Tilegrid with the bitmap and put in the displayio group
    # CircuitPython 6 & 7 compatible
    t = displayio.TileGrid(
        pic, pixel_shader=getattr(pic, "pixel_shader", displayio.ColorConverter())
    )
    # CircuitPython 7 compatible only
    # t = displayio.TileGrid(pic, pixel_shader=pic.pixel_shader)
    g.append(t)

    # Place the display group on the screen (does not refresh)
    display.show(g)

    # Show the image on the display
    display.refresh()

    print("refreshed")

    # Do Not refresh the screen more often than every 180 seconds
    #   for eInk displays! Rapid refreshes will damage the panel.
    time.sleep(180)

For the breakout, you will want to change the epd_reset and epd_busy to the correct values. If you wired it up as shown on the Wiring page, you will want to change it to these values:

epd_reset = board.D8
epd_busy = board.D7

For the shield, you will want to change both of these values to None:

epd_reset = None
epd_busy = None

The rotation of the breakout is 180 degrees different from the shield, so you may want to change the rotation value from 90 to 270:

rotation=270

Save it to your CIRCUITPY drive as code.py and it should automatically run. Your display will look something like this:

It's easy to use eInk breakouts with Python and the Adafruit CircuitPython EPD library.  This library allows you to easily write Python code to control the display.

Since there are dozens of Linux computers/boards you can use, we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported

Note this is not a kernel driver that will let you have the console appear on the eInk. However, this is handy when you want to use the eInk display purely from 'user Python' code!
You can only use this technique with Linux/computer devices that have hardware SPI support, and not all single board computers have an SPI device, so check before continuing

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling SPI on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Python Installation of EPD Library

Once that's done, from your command line run the following command:

sudo pip3 install adafruit-circuitpython-epd

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

If that complains about pip3 not being installed, then run this first to install it:

sudo apt-get install python3-pip

Download font5x8.bin

This library also requires a font file to run! You can download it below. Before continuing, make sure the folder you are running scripts from contains the font5x8.bin file.

Alternatively, you can use wget to directly download the file to your pi:

wget https://github.com/adafruit/Adafruit_CircuitPython_framebuf/raw/main/examples/font5x8.bin

DejaVu TTF Font

Raspberry Pi usually comes with the DejaVu font already installed, but in case it didn't, you can run the following to install it:

sudo apt-get install fonts-dejavu

This package was previously calls ttf-dejavu, so if you are running an older version of Raspberry Pi OS, it may be called that.

Pillow Library

Some of the examples also use PIL, the Python Imaging Library, to allow graphics and using text with custom fonts. There are several system libraries that PIL relies on, so installing via a package manager is the easiest way to bring in everything:

sudo apt-get install python3-pil

That's it. You should be ready to go.

Note this is not a kernel driver that will let you have the console appear on the eInk. However, this is handy when you want to use the eInk display purely from 'user Python' code!
You can only use this technique with Linux/computer devices that have hardware SPI support, and not all single board computers have an SPI device, so check before continuing

To demonstrate the usage of the display, we'll initialize it and draw some lines from the Python REPL.

Run the following code to import the necessary modules and set up the pin assignments. The SRAM CS pin is set to None because the Raspberry Pi has lots of RAM, so you don't really need it.

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

spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
ecs = digitalio.DigitalInOut(board.CE0)
dc = digitalio.DigitalInOut(board.D22)
rst = digitalio.DigitalInOut(board.D27)
busy = digitalio.DigitalInOut(board.D17)
srcs = None
Depending on the exact E-Ink display you're using, the driver and object initialization will differ a bit because Python must be told what chip driver to use and the size of the display.

Run the following code to initialize the 2.7" 264x176 Tri-Color display:

Angled shot of a Adafruit 2.7" Tri-Color eInk / ePaper Display with SRAM - Red Black White.
Easy e-paper finally comes to microcontrollers, with this breakout that's designed to make it a breeze to add a tri-color eInk display. Chances are you've seen one of those...
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from adafruit_epd.il91874 import Adafruit_IL91874
display = Adafruit_IL91874(176, 264, spi, cs_pin=ecs, dc_pin=dc, sramcs_pin=srcs, rst_pin=rst, busy_pin=busy)

Tri-Color Example

The Tri-Color example is almost the same as the monochrome example, except another color is added in. Once done drawing, the code needs to tell the screen to update using the display() method.

display.rotation = 3
display.fill(Adafruit_EPD.WHITE)

display.fill_rect(20, 20, 50, 60, Adafruit_EPD.RED)
display.hline(80, 30, 60, Adafruit_EPD.BLACK)
display.vline(80, 30, 60, Adafruit_EPD.BLACK)

display.display()

Your display will look something like this:

That's all there is to drawing simple shapes with eInk displays and CircuitPython!

Full Example Code

Here is the full example code.

To run the code sample below, you will need to change the pins the same way as you did in the Tri-color Bitmap Example.
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import digitalio
import busio
import board
from adafruit_epd.epd import Adafruit_EPD
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874  # pylint: disable=unused-import
from adafruit_epd.il0398 import Adafruit_IL0398  # pylint: disable=unused-import
from adafruit_epd.ssd1608 import Adafruit_SSD1608  # pylint: disable=unused-import
from adafruit_epd.ssd1675 import Adafruit_SSD1675  # pylint: disable=unused-import
from adafruit_epd.ssd1680 import Adafruit_SSD1680  # pylint: disable=unused-import
from adafruit_epd.ssd1681 import Adafruit_SSD1681  # pylint: disable=unused-import
from adafruit_epd.uc8151d import Adafruit_UC8151D  # pylint: disable=unused-import

# 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 drivers
print("Creating display")
# display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
# display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
# display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color display
# display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
# display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
# display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
# display = Adafruit_UC8151D(128, 296,        # 2.9" mono flexible display
# display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
# display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy,
)

# IF YOU HAVE A 2.13" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, False)
# display.set_color_buffer(1, False)

# IF YOU HAVE A 2.9" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, True)
# display.set_color_buffer(1, True)

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()

Bitmap Example

Here's a complete example of how to display a bitmap image on your display. Note that any .bmp image you want to display must be exactly the size of your display. The image below will be used on the 2.7" display. Click the button below to download the image and save it as blinka.bmp on your Raspberry Pi. The code uses a Tri-Color bitmap, but it should still work on a monochrome display.

Save the following code to your Raspberry Pi as epd_bitmap.py.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import digitalio
import busio
import board
from adafruit_epd.epd import Adafruit_EPD
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874  # pylint: disable=unused-import
from adafruit_epd.il0398 import Adafruit_IL0398  # pylint: disable=unused-import
from adafruit_epd.ssd1608 import Adafruit_SSD1608  # pylint: disable=unused-import
from adafruit_epd.ssd1675 import Adafruit_SSD1675  # pylint: disable=unused-import
from adafruit_epd.ssd1680 import Adafruit_SSD1680  # pylint: disable=unused-import
from adafruit_epd.ssd1681 import Adafruit_SSD1681  # pylint: disable=unused-import
from adafruit_epd.uc8151d import Adafruit_UC8151D  # pylint: disable=unused-import


# create the spi device and pins we will need
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
ecs = digitalio.DigitalInOut(board.D10)
dc = digitalio.DigitalInOut(board.D9)
srcs = digitalio.DigitalInOut(board.D7)  # can be None to use internal memory
rst = digitalio.DigitalInOut(board.D11)  # can be None to not use this pin
busy = digitalio.DigitalInOut(board.D12)  # can be None to not use this pin

# give them all to our driver
print("Creating display")
# display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
# display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
# display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color display
# display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
# display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
# display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
# display = Adafruit_UC8151D(128, 296,        # 2.9" mono flexible display
# display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
# display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy,
)

# IF YOU HAVE A 2.13" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, False)
# display.set_color_buffer(1, False)

# IF YOU HAVE A 2.9" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, True)
# display.set_color_buffer(1, True)

display.rotation = 0

FILENAME = "blinka.bmp"


def read_le(s):
    # as of this writting, int.from_bytes does not have LE support, DIY!
    result = 0
    shift = 0
    for byte in bytearray(s):
        result += byte << shift
        shift += 8
    return result


class BMPError(Exception):
    pass


def display_bitmap(epd, filename):  # pylint: disable=too-many-locals, too-many-branches
    try:
        f = open(filename, "rb")  # pylint: disable=consider-using-with
    except OSError:
        print("Couldn't open file")
        return

    print("File opened")
    try:
        if f.read(2) != b"BM":  # check signature
            raise BMPError("Not BitMap file")

        bmpFileSize = read_le(f.read(4))
        f.read(4)  # Read & ignore creator bytes

        bmpImageoffset = read_le(f.read(4))  # Start of image data
        headerSize = read_le(f.read(4))
        bmpWidth = read_le(f.read(4))
        bmpHeight = read_le(f.read(4))
        flip = True

        print(
            "Size: %d\nImage offset: %d\nHeader size: %d"
            % (bmpFileSize, bmpImageoffset, headerSize)
        )
        print("Width: %d\nHeight: %d" % (bmpWidth, bmpHeight))

        if read_le(f.read(2)) != 1:
            raise BMPError("Not singleplane")
        bmpDepth = read_le(f.read(2))  # bits per pixel
        print("Bit depth: %d" % (bmpDepth))
        if bmpDepth != 24:
            raise BMPError("Not 24-bit")
        if read_le(f.read(2)) != 0:
            raise BMPError("Compressed file")

        print("Image OK! Drawing...")

        rowSize = (bmpWidth * 3 + 3) & ~3  # 32-bit line boundary

        for row in range(bmpHeight):  # For each scanline...
            if flip:  # Bitmap is stored bottom-to-top order (normal BMP)
                pos = bmpImageoffset + (bmpHeight - 1 - row) * rowSize
            else:  # Bitmap is stored top-to-bottom
                pos = bmpImageoffset + row * rowSize

            # print ("seek to %d" % pos)
            f.seek(pos)
            rowdata = f.read(3 * bmpWidth)
            for col in range(bmpWidth):
                b, g, r = rowdata[3 * col : 3 * col + 3]  # BMP files store RGB in BGR
                if r < 0x80 and g < 0x80 and b < 0x80:
                    epd.pixel(col, row, Adafruit_EPD.BLACK)
                elif r >= 0x80 and g >= 0x80 and b >= 0x80:
                    pass  # epd.pixel(row, col, Adafruit_EPD.WHITE)
                elif r >= 0x80:
                    epd.pixel(col, row, Adafruit_EPD.RED)
    except OSError:
        print("Couldn't read file")
    except BMPError as e:
        print("Failed to parse BMP: " + e.args[0])
    finally:
        f.close()
    print("Finished drawing")


# clear the buffer
display.fill(Adafruit_EPD.WHITE)
display_bitmap(display, FILENAME)
display.display()

Before running it, you will need to change a few pin definitions. Find the section of code that looks like this:

ecs = digitalio.DigitalInOut(board.D10)
dc = digitalio.DigitalInOut(board.D9)
srcs = digitalio.DigitalInOut(board.D7)    # can be None to use internal memory
rst = digitalio.DigitalInOut(board.D11)    # can be None to not use this pin
busy = digitalio.DigitalInOut(board.D12)   # can be None to not use this pin

Change the pins to the following to match the wiring on the Raspberry Pi:

ecs = digitalio.DigitalInOut(board.CE0)
dc = digitalio.DigitalInOut(board.D22)
srcs = None
rst = digitalio.DigitalInOut(board.D27)
busy = digitalio.DigitalInOut(board.D17)

Next, find the section that looks like this:

# display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
# display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
# display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color display
# display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
# display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
# display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
# display = Adafruit_UC8151D(128, 296,        # 2.9" mono flexible display
# display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
# display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy,
)

Comment out these lines:

display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display

and uncomment the line that corresponds with your display. 

Next to tell the display the rotation setting desired. This can be a value between 0-3. For the 2.7" displays, a value of 3 seems to work well.

display.rotation = 3

Now go to the command prompt on your Raspberry Pi and run the script with the following command:

python3 epd_bitmap.py

After a few seconds, your display should show an image like this:

Image Drawing with Pillow

This example will use Pillow to resize and crop the image automatically and draw it on the the ePaper Display. Pillow is really powerful and with it you can open and render additional file formats such as PNG or JPG. Start with downloading a PNG of blinka that has been adjusted down to 3 colors so it prints nicely on an ePaper Display. This uses a PNG format file because it is a lossless format and won't introduce unexpected colors on the display.

Make sure you save it as blinka.png and place it in the same folder as your script. Here's the code to load onto the Raspberry Pi. Go ahead and copy it onto your Raspberry Pi and save it as epd_pillow_image.py

# SPDX-FileCopyrightText: 2019 Melissa LeBlanc-Williams for Adafruit Industries
# SPDX-License-Identifier: MIT

"""
Image resizing and drawing using the Pillow Library. For the image, check out the
associated Adafruit Learn guide at:
https://learn.adafruit.com/adafruit-eink-display-breakouts/python-code

"""

import digitalio
import busio
import board
from PIL import Image
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874  # pylint: disable=unused-import
from adafruit_epd.il0398 import Adafruit_IL0398  # pylint: disable=unused-import
from adafruit_epd.ssd1608 import Adafruit_SSD1608  # pylint: disable=unused-import
from adafruit_epd.ssd1675 import Adafruit_SSD1675  # pylint: disable=unused-import
from adafruit_epd.ssd1680 import Adafruit_SSD1680  # pylint: disable=unused-import
from adafruit_epd.ssd1681 import Adafruit_SSD1681  # pylint: disable=unused-import
from adafruit_epd.uc8151d import Adafruit_UC8151D  # pylint: disable=unused-import


# create the spi device and pins we will need
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
ecs = digitalio.DigitalInOut(board.CE0)
dc = digitalio.DigitalInOut(board.D22)
srcs = None
rst = digitalio.DigitalInOut(board.D27)
busy = digitalio.DigitalInOut(board.D17)

# give them all to our driver
# display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
# display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
# display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color or mono display
# display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
# display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
# display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
# display = Adafruit_UC8151D(128, 296,        # 2.9" mono flexible display
# display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
# display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy,
)

# IF YOU HAVE A 2.13" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, False)
# display.set_color_buffer(1, False)

# IF YOU HAVE A 2.9" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, True)
# display.set_color_buffer(1, True)

display.rotation = 1

image = Image.open("blinka.png")

# Scale the image to the smaller screen dimension
image_ratio = image.width / image.height
screen_ratio = display.width / display.height
if screen_ratio < image_ratio:
    scaled_width = image.width * display.height // image.height
    scaled_height = display.height
else:
    scaled_width = display.width
    scaled_height = image.height * display.width // image.width
image = image.resize((scaled_width, scaled_height), Image.BICUBIC)

# Crop and center the image
x = scaled_width // 2 - display.width // 2
y = scaled_height // 2 - display.height // 2
image = image.crop((x, y, x + display.width, y + display.height)).convert("RGB")

# Convert to Monochrome and Add dithering
# image = image.convert("1").convert("L")

# Display image.
display.image(image)
display.display()

The code starts with library imports including a couple of Pillow modules and the ePaper display drivers.

import digitalio
import busio
import board
from PIL import Image, ImageDraw
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874
from adafruit_epd.il0398 import Adafruit_IL0398
from adafruit_epd.ssd1608 import Adafruit_SSD1608
from adafruit_epd.ssd1675 import Adafruit_SSD1675
from adafruit_epd.ssd1680 import Adafruit_SSD1680
from adafruit_epd.ssd1681 import Adafruit_SSD1681
from adafruit_epd.uc8151d import Adafruit_UC8151D

That is followed by initializing the SPI bus and defining a few pins. The choices allow you to use the same code with the EPD bonnets, if you chose to do so.

spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
ecs = digitalio.DigitalInOut(board.CE0)
dc = digitalio.DigitalInOut(board.D22)
srcs = None
rst = digitalio.DigitalInOut(board.D27)
busy = digitalio.DigitalInOut(board.D17)

These examples work on as many displays as possible with very few changes. Go ahead and comment out the following lines:

display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display

and uncomment the line appropriate for your display. 

#display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
#display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
#display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color display
#display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
#display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
#display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
#display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
#display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy
)

Next change the rotation setting to 3.

display.rotation = 3

Next is to open the Blinka image, which is named blinka.png, and it is assumed the file is in the same directory that you are running the script from. Feel free to change it if it doesn't match your configuration.

image = Image.open("blinka.png")

Here's where it starts to get interesting. It is desirable to scale the image so that it matches either the width or height of the display, depending on which is smaller, so that there may be some of the image to chop off when it is cropped. Start by calculating the width to height ratio of both the display and the image. If the height is the closer of the dimensions, you want to match the image height to the display height and let it be a bit wider than the display. Otherwise, you want to do the opposite.

Once you've figured out how to scale it, pass in the new dimensions and using a Bicubic rescaling method, the code reassigns the newly rescaled image back to image. Pillow has quite a few different methods to choose from, but Bicubic does a great job and is reasonably fast.

Nearest actually gives a little better result with the Tri-color eInks, but loses detail with displaying a color image on the monochrome display, so this code uses the best balance.

image_ratio = image.width / image.height
screen_ratio = display.width / display.height
if screen_ratio < image_ratio:
    scaled_width = image.width * display.height // image.height
    scaled_height = display.height
else:
    scaled_width = display.width
    scaled_height = image.height * display.width // image.width
image = image.resize((scaled_width, scaled_height), Image.BICUBIC)

Next to figure the starting x and y points of the image to begin cropping so that the image ends up centered. Do that by using a standard centering function, which is basically requesting the difference of the center of the display and the center of the image. Just like with scaling, replace the image variable with the newly cropped image.

x = scaled_width // 2 - display.width // 2
y = scaled_height // 2 - display.height // 2
image = image.crop((x, y, x + display.width, y + display.height)).convert("RGB")

Finally, take the image, draw it to the frame buffer and display it. At this point, the image should have the exact same dimensions at the display and fill it completely.

display.image(image)
display.display()

Now go to the command prompt on your Raspberry Pi and run the script with the following command:

python3 epd_pillow_image.py

After a few seconds, your display should show this image:

Drawing Shapes and Text with Pillow

The next example takes a look at drawing shapes and text. This is very similar to the displayio example, but it uses Pillow instead. Go ahead and copy it onto your Raspberry Pi and save it as epd_pillow_demo.py. Here's the code for that.

# SPDX-FileCopyrightText: 2019 Melissa LeBlanc-Williams for Adafruit Industries
# SPDX-License-Identifier: MIT

"""
ePaper Display Shapes and Text demo using the Pillow Library.

"""

import digitalio
import busio
import board
from PIL import Image, ImageDraw, ImageFont
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874  # pylint: disable=unused-import
from adafruit_epd.il0398 import Adafruit_IL0398  # pylint: disable=unused-import
from adafruit_epd.ssd1608 import Adafruit_SSD1608  # pylint: disable=unused-import
from adafruit_epd.ssd1675 import Adafruit_SSD1675  # pylint: disable=unused-import
from adafruit_epd.ssd1680 import Adafruit_SSD1680  # pylint: disable=unused-import
from adafruit_epd.ssd1681 import Adafruit_SSD1681  # pylint: disable=unused-import
from adafruit_epd.uc8151d import Adafruit_UC8151D  # pylint: disable=unused-import

# First define some color constants
WHITE = (0xFF, 0xFF, 0xFF)
BLACK = (0x00, 0x00, 0x00)
RED = (0xFF, 0x00, 0x00)

# Next define some constants to allow easy resizing of shapes and colors
BORDER = 20
FONTSIZE = 24
BACKGROUND_COLOR = BLACK
FOREGROUND_COLOR = WHITE
TEXT_COLOR = RED

# create the spi device and pins we will need
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
ecs = digitalio.DigitalInOut(board.CE0)
dc = digitalio.DigitalInOut(board.D22)
srcs = None
rst = digitalio.DigitalInOut(board.D27)
busy = digitalio.DigitalInOut(board.D17)

# give them all to our driver
# display = Adafruit_SSD1608(200, 200,        # 1.54" HD mono display
# display = Adafruit_SSD1675(122, 250,        # 2.13" HD mono display
# display = Adafruit_SSD1680(122, 250,        # 2.13" HD Tri-color or mono display
# display = Adafruit_SSD1681(200, 200,        # 1.54" HD Tri-color display
# display = Adafruit_IL91874(176, 264,        # 2.7" Tri-color display
# display = Adafruit_IL0373(152, 152,         # 1.54" Tri-color display
# display = Adafruit_UC8151D(128, 296,        # 2.9" mono flexible display
# display = Adafruit_IL0373(128, 296,         # 2.9" Tri-color display
# display = Adafruit_IL0398(400, 300,         # 4.2" Tri-color display
display = Adafruit_IL0373(
    104,
    212,  # 2.13" Tri-color display
    spi,
    cs_pin=ecs,
    dc_pin=dc,
    sramcs_pin=srcs,
    rst_pin=rst,
    busy_pin=busy,
)

# IF YOU HAVE A 2.13" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, False)
# display.set_color_buffer(1, False)

# IF YOU HAVE A 2.9" FLEXIBLE DISPLAY uncomment these lines!
# display.set_black_buffer(1, True)
# display.set_color_buffer(1, True)

display.rotation = 1

image = Image.new("RGB", (display.width, display.height))

# Get drawing object to draw on image.
draw = ImageDraw.Draw(image)

# Draw a filled box as the background
draw.rectangle((0, 0, display.width - 1, display.height - 1), fill=BACKGROUND_COLOR)

# Draw a smaller inner foreground rectangle
draw.rectangle(
    (BORDER, BORDER, display.width - BORDER - 1, display.height - BORDER - 1),
    fill=FOREGROUND_COLOR,
)

# Load a TTF Font
font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", FONTSIZE)

# Draw Some Text
text = "Hello World!"
(font_width, font_height) = font.getsize(text)
draw.text(
    (display.width // 2 - font_width // 2, display.height // 2 - font_height // 2),
    text,
    font=font,
    fill=TEXT_COLOR,
)

# Display image.
display.image(image)
display.display()

Just like in the last example, use the imports, but this time include the ImageDraw and ImageFont Pillow modules to allow text rendering.

import digitalio
import busio
import board
from PIL import Image, ImageDraw, ImageFont
from adafruit_epd.il0373 import Adafruit_IL0373
from adafruit_epd.il91874 import Adafruit_IL91874
from adafruit_epd.il0398 import Adafruit_IL0398
from adafruit_epd.ssd1608 import Adafruit_SSD1608
from adafruit_epd.ssd1675 import Adafruit_SSD1675
from adafruit_epd.ssd1680 import Adafruit_SSD1680
from adafruit_epd.ssd1681 import Adafruit_SSD1681
from adafruit_epd.uc8151d import Adafruit_UC8151D

Next to define some colors that can be used with Pillow.

WHITE = (0xFF, 0xFF, 0xFF)
BLACK = (0x00, 0x00, 0x00)
RED = (0xFF, 0x00, 0x00)

After that, create some parameters that are easy to change. If you had a smaller display for instance, you could reduce the FONTSIZE and BORDER parameters. The BORDER will be the size in pixels of the green border between the edge of the display and the inner purple rectangle. The FONTSIZE will be the size of the font in points so that it can adjust easily for different displays. You could play around with the colors as well. One thing to note is that on monochrome displays, RED will show up as BLACK.

For the 2.7" display, a BORDER value of 20 and a FONTSIZE value of 24 looks good.

BORDER = 10
FONTSIZE = 20
BACKGROUND_COLOR = BLACK
FOREGROUND_COLOR = WHITE
TEXT_COLOR = RED

After that, the initializer and rotation sections are exactly the same as in the previous example. Go ahead and adjust your initializer as explained in the previous example. After that, create an image with the dimensions and use that to create a draw object.  The draw object will have all of the drawing functions.

image = Image.new('RGB', (display.width, display.height))

draw = ImageDraw.Draw(image)

Next clear whatever is on the screen by drawing a rectangle using the BACKGROUND_COLOR that takes up the full screen.

draw.rectangle((0, 0, display.width, display.height), fill=BACKGROUND_COLOR)

Next to draw an inner rectangle using the FOREGROUND_COLOR. Use the BORDER parameter to calculate the size and position to draw the rectangle.

draw.rectangle((BORDER, BORDER, display.width - BORDER - 1, display.height - BORDER - 1),
               fill=FOREGROUND_COLOR)

Next to load a TTF font. The DejaVuSans.ttf font should come preloaded on your Pi in the location in the code. This will also make use of the FONTSIZE parameter discussed earlier.

font = ImageFont.truetype('/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf', FONTSIZE)

Now to draw the text Hello World onto the center of the display. You may recognize the centering calculation was the same one used to center crop the image in the previous example. In this example though, the font size values are obtained using the getsize() function of the font object.

text = "Hello World!"
(font_width, font_height) = font.getsize(text)
draw.text((display.width//2 - font_width//2, display.height//2 - font_height//2),
          text, font=font, fill=TEXT_COLOR)

Finally, just like before, display the image.

display.image(image)
display.display()

Now go to the command prompt on your Raspberry Pi and run the script with the following command:

python3 epd_pillow_demo.py

After a few seconds, your display should show this image:

This guide was first published on May 17, 2022. It was last updated on 2022-05-17 21:13:05 -0400.