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Topic: Waveshare e-paper displays with SPI (Read 183240 times) previous topic - next topic

Manu84

@zinggjm

this morning I ask Good display about partial refresh problem,
Here there answer:

"epaper display should not be used outdoors because of its diaphragm limit.
So this year we introduced new technology,  We've got the patent. The new technology epaper display can be used outside and will not be hurt by ultraviolet rays.
New products will be introduced by the end of the year.

In addition,  the 4.2 inch epaper display not support partial refresh because its chip.  Do you consider using 4.3 inch epaper display?
It's parallel interface display and partial refresh is 300ms, Pls find attached datasheet for your reference."

Well, I ask them to understand how some people get goo result with partial update..

ZinggJM

Yes, sometimes I am disappointed by Good Display.

Quote
epaper display should not be used outdoors because of its diaphragm limit.
Some of their e-paper displays are advertised as being "outdoor Anti UV", e.g.
1.54 inch e-paper display anti-ultraviolet 200x200 partial update GDEP015OC1

Quote
In addition,  the 4.2 inch epaper display not support partial refresh because its chip.
But they advertise as "Features´╝Ü Partial refresh" and provide a partial update demo code:
GDEW042T2 demo code_partial refresh20180405

Quote
Do you consider using 4.3 inch epaper display?
It's parallel interface display and partial refresh is 300ms
This e-paper display is hard to use; you need a large connection board with a large special STM32 board.

Fortunately they are willing to learn, and do corrections on their web-site, e.g. when I tell them about links to wrong controller specs.

Jean-Marc

No personal message please; any question may be useful for other users. Use code tags for code. Make links clickable with URL tags. Provide links to the product in question.

ZinggJM

@Manu84,

As I now do have a Waveshare 4.2" b/w board with the actual GDEW042T2 panel, and you told "I just not need fast, but clean without flash", I could try to create a modified wavetable with improved partial update result. It most likely will show some flashing in the partial window, and be considerably slower.

But this depends on your patience.

Note that the main market segment for Good Display is electronic shelf labels, badges, room plates and such, where partial update is not of importance.

I know that the main application for Arduino users is weather stations and such. Flashing just doesn't look nice.
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Manu84

#1428
Today at 04:36 pm Last Edit: Today at 04:40 pm by Manu84
@zinggjm

I made a test this afternoon:

I completely replace all your lut table with table from Ben K.

Partial update work now! background image become a little grey, but that's ok, and there not more blurred on updated text.

So, problem is table... I didn't investigate at this time.

Regards

ZinggJM

#1429
Today at 06:10 pm Last Edit: Today at 06:14 pm by ZinggJM
Ok, then I need to dig out the original table from Ben Krasnow on my old notebook.
I thought it uses the same phase length as the Good Display demo.
My version looks different, as it has the optional sustain phase, with length set to zero to correspond to the demo version.

But I may be wrong, it is quite a while ago I did that.

Consequence is I will verify with the original demo version, to make sure my library is not worse.

@Manu84, You have a version that works for you, for your scenario, so there is nothing more needed from my side.
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SolarDude

@manu84 If you want rapid updates without flashing along with daylight readable then you can consider the Sharp Memory LCD displays in the 4.4 inch size. They do not have low temp display slow down times.

I'm considering eInk displays because I'm looking for more pixels than the Sharp Memory LCD 4.4 inches 320 x 240. They do have 3.2 inch version a 540 x360 pixels and a backlight on Digikey.

ZinggJM Thanks for your work on all this!


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