Cale-idf adds support for 7 color epapers

A project log for CALE Low Energy Eink Calendar

Long-life battery powered photo frame that renders a Screen every morning and goes to sleep - WebService to render Bitmaps

Martin FasaniMartin Fasani 03/06/2021 at 16:100 Comments

Some weeks after we added color support for our epaper component we are announcing also support for 7 color epapers and demo Firmware to render a full color bitmap on this displays.

Original picture:

Rendered using 3x3 dither mode in a Waveshare 4.01 7 color Acep epaper

Of course it does not look like a high resolution color picture, the dither mode reduces the colors to 4 bits per pixel, also 16 colors, but the Epaper supports only less than half: 7 colors. So there is no wonder that the colors look a bit washed out and could only look better in a big epaper and looking it from some distance. But we need to face reality here: this Eink displays are designed for price labels. Not really meant to display a full color picture,p. Not even the full color phone Hisense A5 does it. It renders more colors than 607 but is still not photo quality. 

Class in our IDF component:

For a 7 color example that can render either a 4 bits per pixel or 24 bmp example please check cale-7-color.cpp example in the same repository.