Enhance display/waveshare_epaper component with support for 2bit grayscale on supported 7.5inch display

[cromelex]

Component name

display/waveshare_epaper

Link to component documentation on our website

https://esphome.io/components/display/waveshare_epaper/

Describe the enhancement

The waveshare_epaper component as it works today seems to allow only allow B/W rendering on displays such as the 7.50inV2 and 7.50inV2p, in my understanding due to memory limitations.

This type of display is being used by the folks at TRMNL, and someone has done an implementation that allows 2 bit grayscale to be displayed on these epapers.

usetrmnl/trmnl-firmware#201

If someone could potentially "port" this into ESPHome, it would probably be an interesting improvement over the existing functionality

Use cases

Grayscale with 4 or 8 colours would potentially allow an epaper display to be much more useful for displaying Home Assistant information or dashboards (via online_image component).

Anything else?

No response

[AuHau]

There is the same problem with the Inkplate component, where it supports 3-bit grayscale colors. But if you use for example the online_image component and specify the type to be GRAYSCALE, then it outputs colors in 8-bits.

[tristankin]

Oh wow, I am not alone, I have spent a few hours trying to work out who to moan to about this. :D

Main reason for me is font anti-aliasing to make the 800x480 screen more legible. Kindles have a similar resolution but much clearer text. I already turned on bpp: 2 and that is slightly clearer but the extra bits are just being rendered black.