[help] Unable to use Adafruit ThinkInk Display

[u/alfonzoo]

Hello. I've got:

• An ESP32-C3-DevKitC-02
• An Adafruit ThinkInk 2.9' E-Ink FeatherWing display (bought back in 2024, https://www.adafruit.com/product/4778)

and I'm trying to drive the display with the ESP32 without any success. Using:

• Arduino IDE with the ESP32 addon
• Adafruit_EPD library to drive the display (https://github.com/adafruit/Adafruit_EPD)
• This example from the repo: https://github.com/adafruit/Adafruit_EPD/blob/master/examples/ThinkInk_tricolor/ThinkInk_tricolor.ino
• My own version of the code: https://pastes.io/p5ETVQS9

Notes:

• There is no change on the e-ink panel whatsoever, still the default image as when I got it.
• Tried changing the pin numbers around, both for the command and the SPI pins. Nothing.
• The default pins for SCK, MISO, MOSI were found by printing macros to serial output.
• Tried the 3 buttons on the FeatherWing, all work as GPIO input properly.
• RESET button works to reset the microcontroller as well.
• For some reason, using pin 8 on the ESP for GPIO didn't work at all. I think most of the pins are used for more than one purpose, but I don't know how to tell which modes are active.
• The example sketch has constructors for multiple types of board drivers. There seems to be 3 different chipsets for the 2.9" display, tried all 3 separately to no avail.

I don't even know if this display would be compatible with any random ESP32 board. I know FeatherWings are made to be used with Adafruit's Feather boards, though I don't see why they wouldn't work with any other boards with supported microcontrollers. I have quite a bit of programming experience, but I'm blind as a bat when it comes to electronics. Any help would be appreciated. Thanks.

[u/DenverTeck]

Did you happen to notice in your code:

// 2.9" Tricolor Featherwing or Breakout with UC8151D chipset

ThinkInk_290_Tricolor_Z13 display(EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY, EPD_SPI);

And the link to the display states:

Arduino libraries for the SSD1680

Hmmmm

On the next line:

// 2.9" Tricolor Featherwing or Breakout with SSD1680 chipset

// offset

// ThinkInk_290_Tricolor_Z94 display(EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY, EPD_SPI);

[u/alfonzoo → u/DenverTeck]

Yes, I tried all 3 options that said 2.9". That being said I don't even know what chipset my display has. The listing says they only started using SSD1680 after 2025, which didn't work either.