Go Down

Topic: Waveshare e-paper displays with SPI (Read 117997 times) previous topic - next topic

Bjack795

GxEPD2 is the newer and cleaned up version, with a better SW structure.

GxEPD2 is now directly available through Library Manager.

GxEPD2 is easier to use and offers to set the template parameter page_height to adapt memory use for paged drawing.
It supports paged drawing using picture loop like in u8g2, in addition to paged drawing using draw callbacks.
It also supports full buffered drawing with page_height set to display height. Use display() instead of update().

GxEPD and GxEPD2 support the same e-paper displays I have. GxEPD will continue to be supported, because it is more widely in use.

Jean-Marc

Ok perfect, thank you.
After all these discussions I hope to test your code soon :)

4lexO

GxEPD2 is the newer and cleaned up version, with a better SW structure.

GxEPD2 is now directly available through Library Manager.

GxEPD2 is easier to use and offers to set the template parameter page_height to adapt memory use for paged drawing.
It supports paged drawing using picture loop like in u8g2, in addition to paged drawing using draw callbacks.
It also supports full buffered drawing with page_height set to display height. Use display() instead of update().

GxEPD and GxEPD2 support the same e-paper displays I have. GxEPD will continue to be supported, because it is more widely in use.

Jean-Marc

Hello,
I was wondering what documentation for the different functions we should use ? It is the u8g2 reference ?
regards,
Alex

ZinggJM

Hi Alex,

are you referring to GxEPD2 or GxEPD, and to all methods or to the methods for paged drawing?

Most users start with one of the examples to get an idea how to use these libraries.
And the methods have a one line comment in the header files and meaningful names.

For GxEPD2 you get an overview in these base class headers:
https://github.com/ZinggJM/GxEPD2/blob/master/src/GxEPD2_EPD.h
https://github.com/ZinggJM/GxEPD2/blob/master/src/GxEPD2_GFX.h
I admit that this "documentation" is very limited.

For GxEPD you get an overview in this base class:
https://github.com/ZinggJM/GxEPD/blob/master/src/GxEPD.h

For the graphics drawing methods consult the documentation of Adafruit_GFX.

Also take a look at the readme files of the libraries, and the link to the explanation for paged drawing in u8g2.

I am not good at documentation. Maybe I find some time for this sometime.

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.

4lexO

Thank you ZinggJM for your reply.
I am referring to GxEPD2 and to all method. I will try to figure out with the example and the base class header you are referring to.

I will try to do the documentation by myself and make a proposal (to you) if I find the time too.

Regards,
Alex

Narceen

Hello,

is there an way to rotate a picture for like 10degree before printing it to the screen?

ZinggJM

#875
Nov 16, 2018, 03:36 pm Last Edit: Nov 16, 2018, 03:55 pm by ZinggJM
Hello Narceen,

Yes, there is a way to do that, but it is a complex mathematical operation.
So it is easier to let a graphical tool on a PC do that task.

There may be libraries that can do it on an Arduino with powerful processor and enough ram.
A Raspberry Pi or Orange Pi may also be a choice.

Adafruit_GFX can rotate 90 degrees and multiples of it, so you would use buffered graphics for this.

Jean-Marc

I found this topic: Rotating a bitmap
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.

georg77cz

Hi Jean-Marc,

I just want to post an update on my issues:

  • I had to use a different MOSFET in my high voltage booster, Good Display recommended to me to replace 2N7002K-7 by AO3400.
  • I connected the two Schottky rectifiers in reverse polarity  :smiley-eek-blue:
  • Bought an FPC breakout board to replace my custom soldered FPC connector


Now it is finally working, thanks! :)


Hi Jean-Marc,

after a long time, I returned to playing with E-ink display but still had no luck to make it work :(


This time, I decided to improve my setup
  • I have built a custom high voltage booster on breadboard (based on Good display specification, just wasn't sure how to connect VCI)
  • Got two more e-inks to make sure the problem is not in the display itself (Good display B/W 4.2" and 2.9")
  • I made sure the 24pin connector on the breadboard is not having a loose connection
  • Still using Sparkfun ESP32 Thing with the recommended pinout (BUSY -> 4, RST -> 16, DC -> 17, CS -> SS(5), CLK -> SCK(18), DIN -> MOSI(23), GND -> GND, 3.3V -> 3.3V)
  • Tried both GxEPD and GxEPD2 (via Platform.io)


I guess the output looks better this time but still no change on the display :(

_PowerOn : 1
_Update_Part : 1
helloFullScreenPartialMode done
_Update_Part : 0
helloArduino done
helloEpaper
_Update_Part : 0
helloEpaper done
_Update_Full : 1
_Update_Part : 1
_PowerOff : 1
_PowerOn : 1
_Update_Full : 1



Power On : 6
drawBitmap : 1
drawBitmap : 1
Power Off : 1
Power On : 1
drawBitmap : 7
Power Off : 1
Power On : 3
update : 1
Power Off : 1
Power On : 1
drawCornerTest : 1
Power Off : 1
Power On : 3
update : 1
Power Off : 1
Power On : 1
update : 1
Power Off : 1



Thanks again!
Jiri

ZinggJM

I got the following question asked for GxEPD2: issue #3

Quote
Is it possible to add support for the Waveshare 9.7 1200x825 display?
https://www.waveshare.com/product/modules/oleds-lcds/e-paper/9.7inch-e-Paper.htm

It looks like a great display with 16 shades of greyscale support and a very fast refresh rate of less than a second.
This is my answer to the question:

Quote
This display is indeed very interesting. The panel is from Dalian Good Display. The panel has a parallel interface, so neither GxEPD2 nor GxEPD would be directly suitable to support it. GxEPD_HD would be the suitable library to support it, either with the DESTM32-T evaluation board from Good Display or the adapter board from Waveshare.
The price for this e-paper display will not make it used by many Arduino or hobby users. So although I am interested in this display and in supporting it, I would need a sponsor or donator to get me such a display. Neither Waveshare nor Good Display showed interest in sponsoring me, not even for the new small SPI e-paper displays; free evaluation samples are only available for volume customers.
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.

witchole

#878
Nov 18, 2018, 04:45 pm Last Edit: Nov 19, 2018, 11:36 am by witchole
@enkoopa

Thank you for this post and the link! I will buy this gadget and will look into it, too.

...

I propose you create a new topic for this.

Was a new topic created?

I just bought one of these devices and it looks great, but I'm wondering: is it a fully bit-mapped display or is it more like an old LCD watch screen, with only preset areas that can be black or white?

ZinggJM

#879
Nov 18, 2018, 06:00 pm Last Edit: Nov 19, 2018, 09:33 am by ZinggJM
@witchole

There isn't a new topic for it (yet), you could create one, but an issue on GitHub: https://github.com/gcormier/eWeatherStation/issues/1
I did not yet contribute, as my gadget has not yet arrived.

From the picture it is quite obvious that it is a custom segmented e-paper display, not a matrix display.
This explains the rather low price, and the mysterious logic signals.
I wasn't aware of this when I ordered mine, but curiosity is a strong motivator for me.

Now there is a topic for such gadgets: Gadgets with E-Paper Displays Collection
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.

witchole

From the picture it is quite obvious that it is a custom segmented e-paper display, not a matrix display.
This explains the rather low price, and the mysterious logic signals.
I wasn't aware of this when I ordered mine, but curiosity is a strong motivator for me.
My thinking too, but I just saw the screen do a full refresh (whole screen went black then white) instead of a partial refresh of just some of the digits, so I'm now hopeful it is a full matrix display and not a segmented one.

georg77cz

My thinking too, but I just saw the screen do a full refresh (whole screen went black then white) instead of a partial refresh of just some of the digits, so I'm now hopeful it is a full matrix display and not a segmented one.
It's definitely a segmented display, I got mine some time ago ;)

witchole

It's definitely a segmented display, I got mine some time ago ;)
That's a shame. And yet there is "ink"over the whole of the display... Just not addressable?

georg77cz

I guess that's how the technology works, matrix e-ink has a pixel grid, this one has segments only but it's still on the whole canvas.

ZinggJM

Matrix e-paper displays have a TFT grid like TFT displays, segmented e-papers most likely have only conducting fields on glass, like LCD displays. It will be interesting to see if it has some controller on the screen to drive the segments. And to try to measure the voltages used to drive the segments.
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.

Go Up