The V5 and V7 board drive the same eink display, and the display effect is different

[zengcym]

I have a problem, I use v5 and v7 board to drive ED060KD1 display, waveform uses epdiy_ED060XC3, v5 is normal, v7 display color is very light, I have checked VCOM and other voltages, it is consistent. What causes this?
Can you give me some help? thank you。
(Tested, v7 board using epdiy_ED047TC2 waveform file and v5 using epdiy_ED060XC3 waveform file has a similar image effect, But the refresh is slow,whether it is helpful to find the problem.)

[martinberlin]

V5 and v7 drive the panels using different methods. In v7 the firmware has been reworked to work with the new LCD module in S3. That’s why waveforms might act differently.
Please try with a different waveform and also check the issues and discussions about the topic like #340 and others. Many waveforms have to be updated after this.
And hopefully we will see in the future an update about this topic that makes them work uniformly.

[zengcym]

Hello Martin, I will read this carefully, thank you for your great work, and look forward to fixing this bug.

[martinberlin]

Hello @zengcym
Additionally in case it's of your interest I've started writing an article in the epdiy WiKi that covers with more detail how the eink panels are driven with V7. As soon as I research more, will add code snippets and examples there:

https://github.com/vroland/epdiy/wiki/How-pixels-are-driven-in-a-parallel-epaper-with-epdiy

[zengcym]

Hello Martin, I'll be following the content of the page, thank you for your work!

[vroland]

For a workaround, you can try some vendor waveforms like the ED047TC2 waveform and see how it does on your display.