Waveshare e-paper display, spi, zephyr, nrf52840dk

[mej7000]

We would like to develop for the waveshare 1.02 e-paper display. We have limited experience with SPI on Zephyr and are looking for the easiest way to get a "hello world" result using nrf52840dk.

Our plan (unless you suggest otherwise) is to use the  paper-shield and the 1.02inch display.

https://www.waveshare.com/product/displays/e-paper/e-paper-shield-b.htm
https://www.waveshare.com/1.02inch-e-Paper.htm

I don't see anything obvious to get started with Zephyr/Nordic. I am hoping for a "waveshare hello world" to jumpstart our development. Can you suggest the best sample and/or any additional guidance? 

[khelmutlord]

Hey Michael,

I've created this demo for the WaveShare epaper hat. This uses LVGL and the display subsystem in Zephyr and cycles between a couple of different QR codes. You could also use the basic LVGL demo in Zephyr but it may update too often for your display.

https://github.com/hlord2000/Zephyr_ePaper_Demo

Note that you will need to add a "shield" that specifies which display (and thus which controller IC) is being used:

https://docs.zephyrproject.org/latest/boards/shields/waveshare_epaper/doc/index.html

Thanks,

Helmut Lord

[Jenwhiz]

Hi, would you be able to confirm what pins you used to make this work. I used the D9-7 as specified in the waveshare_epaper_gdeh0213b1.overlay file for reset dc and busy. I added an overlay for the SPI pins, but can't seem to get them to work.

[mej7000]

This morning we connected the Waveshare to an Arduino Uno and it worked immediately, so we know the display is good. We bought this one from Amazon:

https://www.amazon.com/dp/B07Z1WYRQH?psc=1&ref=ppx_yo2ov_dt_b_product_details

And we've been using this DSHIELD, although we can't seem to find in the Waveshare specs exactly what Controller the hardware uses (FPC A002 printed on ribbon cable):

west build -b nrf52840dk_nrf52840 -d build52840  -- -DSHIELD=waveshare_epaper_gdeh0213b1

 

our display is 250x122 and the shield seems to generate, something compatible (as far as I can tell)

        width = <250>;

        height = <120>;

Everything compiles without issue, but I was hoping you could give us more insight. We believe the sample uses SPI3 and the following pinout, but we get nothing on the screen...

nrf52840dk (default SPI3):

• MISO (NC)
• MOSI P1.13
• SCK P1.15
• CS P1.12

Waveshare Overlay:

• DC P1.11
• RESET P1.10
• BUSY P1.08

Am I missing something obvious? Any insight is appreciated.

thanks, mike

Zephyr_ePaper_Demo.zip