Hello, I am using Waveshare 7.5inch E-Ink Display with ESP-32(NodeMCU-32S) and with e-Paper Driver HAT rev 2.3.
When I render a black&white image produced using a simple threshold algorithm, the display works fine. However, when I render a dithered image, the display looks pale and without contrast.
Most likely cause for your issue is a wrong position of the RESE switch on the driver HAT.
Second most likely cause is a wrong panel driver selection.
Third would be insufficient supply voltage or stability.
If you need more, then I need to know exactly what you bought, by providing a link.
And the inking you see on the flexible connector of the panel.
And the driver class you selected (this would also show if you use GxEPD or GxEPD2).
And the processor and processor board you use.
-jz-
0.47 Ohms is correct for both 7.5" b/w 800x480 supported by GxEPD2.
But the VCC of 3.3V through the HAT leads to marginal supply, because of the LDO on the HAT.
If you try with 5V VCC, you would need to add a (10k) series resistor on the BUSY line, to protect the processor.
For use of these panels with 3.3V processors, I recommend the DESPI-C02 connection module. Especially for low power use.
-jz-
Hello @ZinggJM, I switched from GxEPD to GxEPD2, and now everything works perfectly. Thanks for your help and advice. I am considering buying the DESPI-C0.