topic Re: Eink mxc_epdc_v2_fb_test problem in i.MX Processors

Eink mxc_epdc_v2_fb_test problem

econote_vikrant — Wed, 13 Mar 2019 07:39:55 GMT

Greetings!

I am using 10.3" eink with imx7dsabresd board, I am facing the problem with unit tests which is default built,

I have attached the image with this question, kindly check it and suggest me what I am missing!

Thanks in advance!

Re: Eink mxc_epdc_v2_fb_test problem

igorpadykov — Wed, 13 Mar 2019 10:55:55 GMT

Hi Vikrant

for new epdc panel one can check suggestions in sect.10.3.3 EPDC Panel Configuration

sect.10.3.4 EPDC Waveform Loading attached Linux Manual.

Best regards
igor
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Re: Eink mxc_epdc_v2_fb_test problem

econote_vikrant — Wed, 13 Mar 2019 11:57:48 GMT

Hi Igor,
Thanks for your reply, but I have done those all steps already and I have the *.fw file converted from NXP only.

Is there any changes required as my panel's SDDO width is 16-bit.

I made changes into driver files accordingly but still I am getting those lines!

Re: Eink mxc_epdc_v2_fb_test problem

igorpadykov — Wed, 13 Mar 2019 22:59:29 GMT

Hi Vikrant

one can look at sect.10.3.4.1 "Using a Default Waveform File" Linux Manual,
so EPDC device driver was linked to correct *.fw file :

"using a nonpanel-specific waveform file for an E Ink panel results in more ghosting
artifacts and overall poorer color quality."

Test can use "default panel" ( first panel described in the video mode table)
in struct imx_epdc_fb_mode panel_modes[], change it to custom:
mxc_epdc_v2_fb.c\mxc\fbdev\video\drivers - linux-imx - i.MX Linux kernel
also check that kernel command line used necessary panel arguments.
Check images used for updating the display. It may not be a correct size for the display.
The EPDC controller does not scale the image.

Best regards
igor

Re: Eink mxc_epdc_v2_fb_test problem

econote_vikrant — Thu, 14 Mar 2019 05:09:57 GMT

Hi Igor,

I have done all the mentioned things in the previous answer, however, my waveform file is also correct, I received panel configurations and timing parameters converted from NXP only, I changed panel modes to custom also, if it wasn't correct I would have not seen those grayscale patterns also, so my only concern is why am I getting those lines as they are not related to ghosting, my panel's SDDO width is 16-bit so are there any other changes required in the driver file regarding any parameter?

I changed SSDO width in the driver file already

Re: Eink mxc_epdc_v2_fb_test problem

igorpadykov — Thu, 14 Mar 2019 05:32:45 GMT

Hi Vikrant

suggest to measure timings with oscilloscope and use eink datasheet to verify

that used correct waveforms and not default. Regarding SDDO width one can debug it

using jtag and driver description in Linux Manual.

Best regards
igor

Re: Eink mxc_epdc_v2_fb_test problem

econote_vikrant — Fri, 22 Mar 2019 07:03:05 GMT

Hi Igor,

As per your suggestion, I have measured all the timings with oscilloscope against the Datasheet of the panel I am using. Everything is going according to the panel timings, but I am not figuring it out why these lines are getting displayed. I even checked vsync as well as num_ce values, tried to modify them but no change. Is there anything you suggest?

Re: Eink mxc_epdc_v2_fb_test problem

igorpadykov — Fri, 22 Mar 2019 07:48:19 GMT

Hi Vikrant

suggest to get additional help with more deeper analysis using

NXP Professional Services | NXP

Best regards
igor