ePaper Display Waveshare 7.5 flickers

ESPHome
1

Hello,

I bought the Waveshare 7.5in ePaper HAT display together with ESP32 Waveshare Universal e-Paper Driver Board.
According to the sticker on the back, it is version 2.
Another sticker is 075BN-T7 and 2021083002 printed.
With each refresh of the display, the screen is repeatedly flicker between black and white, before it is properly redrawn.
What am I doing wrong?

CODE

font:
  - file: 'fonts/OpenSans-Light.ttf'
    id: font1
    size: 80

spi:
  clk_pin: 13
  mosi_pin: 14

display:
  - platform: waveshare_epaper
    cs_pin: 15
    dc_pin: 27
    busy_pin: 25
    reset_pin: 26
    model: 7.50inv2
    update_interval: 10s
    lambda: |-
      it.print(0, 0, id(font1), "Hello World!");

ePaper
ePaper1920×1938 220 KB

2

Nothing is wrong.
That is how an e-ink screen updates.

3

Real?
The whole screen changes about 10 times between black and white, before it is redrawn.
ePaper

4

Shot in the dark…to me it looks like you are reinitialising the display, instead of refreshing it.

5

There are currently a lot of problems with waveshare v2 e-ink screens. For the 2.9 inch screen there is a fix, however the PR is not accepted (yet). 2.7’’ is not working as well. Looks like the 7.5’’ is the next one. I suppose this ESPHome component needs some TLC from a C++ developer.

See also: https://github.com/esphome/issues/issues/2334

1 Like
6

I have a few of the 7.5" V2 screens and that is how they are redrawn.
The 7.5" screens do not have partial update, so the entire screen flash.

There are some attempts at a partial update, so you can give them a try.

1 Like