Driver for WaveShare 4.2 ePaper V2 with micropython on ESP32

[Barbsbou]

Dear all;

I have a LOLIN D32 board and a new WS 4.2 white and Black ePaper on the 2nd version.

I am trying to use the Peter Hinch's driver to do so, I am using the pico_epaper_42.py file modifying the connection Pins and during the initialization step, ssd=SSD() I am looping into the function ready(self) because the (self._busy_pin() == 0) is always true.

Any idea?????
Thanks a lot for your help!!!

[asherevan]

Did you try changing the pin used for the busy pin?
I’m not familiar with the particular hardware you are using, but it is something to try!

[Barbsbou]

Thank you for your reply!

Yes I tried different pin configurations follows the pinout scheme of my board, and I have still the problem...

Another idea?
Thank you in advance!

[Barbsbou]

Do you suspect an hardware problem with my pin?

[asherevan]

Possibly. As I said before, I’m not familiar with your particular hardware, but it is possible. Have you gotten the screen to work by other means? (Other board, driver, etc.) And does the board work other than that problem?

[Barbsbou]

Indeed, I already used this board for different Proof Of Concepts, however it was always with less Pins...
So I will try with another!! I need a little bit time to process all necessary checks!

thank for your replies

[asherevan]

You're welcome!

[Barbsbou]

I tried with a new board, at the beginning, I had the same issue, so I changed the busy pin, and I don't have this problem.

All seems to be good from a software point of view, but the screen state does not change... nothing is printed on the screen....

[Barbsbou]

I read on the pinout on my board, and I used Pins for SPI. After readding hours, these Pins are used to connect/modify the firmware (or something like that)... Then I use Pins for V-SPI, and same problem, nothing happen to the epaper display...

I try to replace SPI with SoftSPI, but I am not sure to understand the difference between them...

[peterhinch]

I'm unclear what display is in use here. This one is designed for the Pico but is supplied with a cable enabling other hosts to be connected. It has been extensively tested with particularly good results. However there is no guarantee of compatibility with other Waveshare displays of the same size.

I can only buy - and write drivers for - a limited number of these things and Waveshare make a vast range of products.

[Barbsbou]

First of all, THANK you a lot for all your shared sources, and I know that as soon as I will success to use my waveshare display I will use your other libraries!

OMG, indeed you are totally right: this is not the same hardware! I have https://www.waveshare.com/wiki/4.2inch_e-Paper_Module_Manual and if I understand correctly, the SPI communication schemes are different...
So I will search into your drivers list, which one is close to my hardware, any idea? I think the epd29driver.py?
Thus I will try to adapt it. If I will success I will share it.

See you from Normandy the 6th June ;-)

[Barbsbou]

Ok After hours of research and try to adapt the code for my display, and understand why it was not work: the drivers proposed are for the V1 hardware, but now the hardware have different versions which change the communication protocol...

Moreover, I don't know if you know but Waveshare adapt the Peter Hinch's python-nano-gui to different hadware version. Link corrected

For my case the adaptation is only for 1-bit monochrome. I will try to modify to adapt to 2-bits grayscale.
Thank you

[peterhinch]

That link is a 404.

[Barbsbou]

Oupsss sorry

Good link

I hope that I don't say anything new for you...

[peterhinch]

Thanks for the link. I wish Waveshare wouldn't do this: their copies are often out of date. It would be better if they linked to my repos.

[Barbsbou]

Sure it is a better practice...