New to E-Paper displays and having a strange issue with a dim display.
I have this display:
And I am using it with this library:
Which is not offically support but it does appear to be the same panel/ SSD1681 driver. AKA GDEH0154Z90 in the library code.
I can get the display to print and work. But after the refresh the display goes 50% dimmer and quickly fades.. Is there some kind of retention setting or why is this happening?
All e-paper panels I support with my libraries use an external adapter with charge pump circuit to generate the panel driving voltages. This may be on the DESPI-C02, or a Waveshare board or HAT.
The website you refer doesn't tell anything about this, as far as I can see.
I have seen small e-paper displays that don't need an external charge pump, just a capacitor for a controller internal charge pump. Most likely yours is such a display. This certainly will need a different initialization code. Try to find code for your display and then compare.
I have implemented my own boost circuitry based on the reference. It is correctly generating the required +20 -20 voltages.
After leaving the display overnight it seems be working properly now. Perhaps just stuck pixel from sitting in a warehouse. I also noticed using a thicker font made a big difference as well.
