EPDiy E-Paper Driver

EPDiy is a driver board which talks to affordable E-Paper (or E-Ink) screens, which are usually sold as replacement screens for E-Book readers. Why are they interesting?

• Easy on the eyes and paper-like aesthetics
• No power consumption when not updating
• Sunlight-readable

Ready-made DIY modules for this size and with 4bpp (16 Grayscale) color support are currently quite expensive. This project uses Kindle replacement screens, which are available for 20$ (small) / 30$ (large) on ebay!

The EPDiy driver board targets multiple E-Paper displays. As the driving method for all matrix-based E-ink displays seems to be more or less the same, only the right connector and timings are needed. The EPDiy PCB v5 features 33pin, 34pin and a 39pin connectors, which allow to drive the following display types: ED097OC4, ED060SC4, ED097TC2, ED060SC7. For the full list of supported displays, refer to the table below.

Revision 5 of the board is optimized for the use with LiPo batteries, featuring a LiPo charger and ultra-low deep sleep current.

This project supports a driver for the ESP-IDF and Arduino. For installation instructions, please refer to the documentation.

Building It

If you want to build a board right now, there are two possible routes:

• Use the new v6 PCB (hardware/epaper-breakout/gerbers_v6.zip). So far, I only tested a prototype of it. The gerbers only contain fixes for powering from battery, but have not yet been ordered with. If you have tested them, please let me know! The BOM is available at (hardware/epaper-breakout/BOM.csv). Positioning files for SMT assembly are available at (hardware/epaper-breakout/gerbers/epaper-breakout-top-pos.csv). Please double check the part positioning and Rotation with your assembly service! More information on the order process and where to find parts is in the documentation.

  Make sure to select the V6 board revision in idf.py menuconfig when building the examples.

• Use the old v5 PCB (hardware/epaper-breakout/gerbers_v5.zip).
  This is the last board using the LT1945 booster. Make sure to select the V5 board revision in idf.py menuconfig when building the examples.

Gettings Started

For instructions and more information visit the documentation!

Join the Discussion

• Matrix Community: +epdiy:matrix.vroland.de
• Slack: See badge Displays

Troubleshooting

The following list is compiled from past experiences and GitHub issues:

• The displayed image displays only part of the image. Make sure to select the correct display type as described here.
• The existing image fades / darkens when updating a partial screen region. Make sure the VCOM voltage is calibrated for your specific display.
• The second third of the image is replaced with the last third. This seems to be a timing issue we could not yet quite figure out the reason for. For a workarround or suggestions please join the discussion.
• The ESP does not boot correctly when external periperals are connected. Make sure not to pull GPIO12 high during boot, as it is a strapping pin internal voltage selection (#17).

LilyGo Boards

There are several differences with these boards. One particular one is the way the LilyGo handles power to the display the official lilygo code has two states. This is now handled in epdiy in a different way to the lilygo code. epd_poweroff() completely turns the power off to the display and the other peripherals of the lilygo. The new function epd_powerdown() keeps the peripherals on (this allows the touch functions to continue to work). epd_poweroff() should allways be called before sleeping the system You can still use touch to wake the screen with the following. In Arduino it works like this. epd_poweroff();

epd_deinit();

esp_sleep_enable_ext1_wakeup(GPIO_SEL_13, ESP_EXT1_WAKEUP_ANY_HIGH);

esp_deep_sleep_start();

More on E-Paper Displays

• List of E-Paper devices and their screens: https://e-ink-reader.ru/chg_dsp_en.php (thanks, @mcer12)
• Reverse engineering of display pins, possible starting point for alternative drivers: https://linux-sunxi.org/PocketBook_Touch_Lux_3 (thanks, @mcer12)
• Reverse engineering and explanation on driving EPDs: http://essentialscrap.com/eink/index.html
• Earlier take on driving 6" EPDs with an ESP32, basis of original power circuit: http://spritesmods.com/?art=einkdisplay&page=1
• Related Hackaday projects: https://hackaday.io/project/21607 https://hackaday.io/project/11537

If you know any other useful resources or have suggestions, please comment on #31!

Hackaday Project

For more details, see the project page on Hackaday: https://hackaday.io/project/168193-epdiy-976-e-paper-controller

Licenses

The weather example is Copyright (c) David Bird 2018 (except for minor modifications). Please refer to examples/weather/README.md for details.

The board and schematic are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Firmware and remaining examples are licensed under the terms of the GNU Lesser GPL version 3. Utilities are licensed under the terms of the MIT license.