Waveshare Display w/Nordic-Zephyr, spi

[mej558]

I would really appreciate help getting a waveshare display to work with a nordic nrf52840dk and zephyr. We were able to get the display working within minutes in Arduino, but it's been weeks struggling with nordic/zephyr.

https://github.com/mej558/lvgl_1.git

• 2.13inch E-Ink Display HAT V4 Version, Black/White Two-Color 250x122 (from amazon)
• There are no recognizable controller marking on the FPC cable. Ours only reads: FPC-A002
• So, we think we should use this DSHIELD: west build -b nrf52840dk_nrf52840 -d build52840 -- -DSHIELD=waveshare_epaper_gdeh0213b72
• https://docs.zephyrproject.org/latest/boards/shields/waveshare_epaper/doc/index.html
• We are using SPI3 pinouts +those designated in the Waveshare DSHIELD, two people have set it up in dependently and correct pins has been triple-checked (as far as we understand the connections)
• Using the LVGL sample
• We get no response at all from the screen
• I noticed that zephyr_display is not defined: display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
• only ~6months into Nordic/Zephyr so we get the basics, but still learning stuff

Any help or guidance would be appreciated. If I have left out anything important please let me know and I will add it.

[WouterHielkema]

Hey! I'm doing a project with a pervasive display and the nrf52840dk now! Have you ever figured this out? Any more information you can share with me to help me along? I'd love to hear from you!

-Wouter

[mej558]

If I remember correctly, the connections as shown are correct.
I think our problem was understanding that you need to compile in the proper shield for your display. And, that there were a limited number of Zephyr supported Waveshare displays?
This folder was important to understanding: C:\ncs\v2.9.1\zephyr\boards\shields\waveshare_epaper
Depending on the display(shield), the command to build is something similar to:
west build -b nrf52840dk_nrf52840 -d build_nrf52840dk_nrf52840 -p -- -DSHIELD=waveshare_epaper_gdey0213b74

Its been a while, so I am a little fuzzy on the details, but I hope that helps. Good luck with your project!