RGB565 Color issue on 480x854 display on sln-viznlc-iot(i.MX RT106F)

[pratik040391]

Hi,

We are using SLN-VIZNLC-IOT Kit for our development. Currently we want to use bigger display instead of the standard display provided with kit. While using the bigger display we are getting color problems and flickering on the display.

Display: RK050HR045B0 (480x854)

Driver IC: ILI9806E

Pixel Format: RGB565

Changes made are as below,

1. Added new file "hal_display_lcdif_rk050hr045b0.c" which is mostly same as "hal_display_lcdif_rk024hh298.c". There are just few changes I have made as compared to rk024hh298.c

---> HSW, HFP, HBP, VSW, VFP, VBP (Provided by display manufacturer)

---> ILI9806E Init sequence (Provided by display manufacturer)

---> Buffer - Height and Width

---> Clock 32MHz (Verified on Oscilloscope)

With above changes if I display only RED, Green or Blue color individually on the display then it works well but let's say If I want to display white color which is "0xFFFF" then it is not display correctly and shown as greenish.

If I want to display slight off white color "0xDEFB" then it displays light purple like color (Attached images here, IMG_0708 - Set Color, IMG_0707 - Actual on Display).

So, This issue occurs with multiple colors.

Are there any other configurations required to use bigger display?

Thanks,

Pratik

[pratik040391]

Thanks @kerryzhou  for the response.

There was an issue with connection and after that fix now I am able display colors correctly. However when I enable camera module I am seeing distortion in the video as attached in the image.

Can you please guide me what could be the issue?

Thanks,

Pratik 

[kerryzhou]

Hi @pratik040391 ,

   Thanks so much for your updated information that your LCD is working, perfect.

   To the camera issues, could you please help to create a new question post about it?

  As normally, one case to one question topic, thanks a lot for your understanding.

Best Regards,

Kerry

[pratik040391 · Accepted solution]

@kerryzhou Everything working fine now except the backlight flickering.

I also found the root cause for that. Basically L13 inductor (attached on UM1663S) which is of 10uH is not capable of driving enough current on BL+ line and due to that I am seeing flickering on the screen. 

LCD we are using has 12 WLEDs and L13 is creating the problem. However with the new design we will optimize it

Thanks,

Pratik

[kerryzhou]

Hi @pratik040391 ,

  Thanks for your experience sharing.

  To the background, yes, it is need to select the proper driver to share enough current.

So, in our application note for the LCD 1024*800, that also use the external higher drive ability circuit.

So, in your own design, select the proper component to match your application.

Best Regards,

Kerry

[pratik040391]

Sure @kerryzhou 

Thank you for all the support. We can now close this thread.

Thanks,

Pratik

[kerryzhou]

Hi @pratik040391 ,

  Really thanks so much for using NXP solution demo:

https://www.nxp.com/design/designs/nxp-edgeready-mcu-based-solution-for-face-recognition-with-livene...

  Yes, you can use bigger LCD, it's OK.

  Just need to modify the code, to match your LCD.

  About use the larger LCD, it is mainly for the lcd driver modification, then the LCD parameter, and the pix clock to match what you wanted FPS .

  Please refer to our application note:

https://www.nxp.com/docs/en/application-note/AN12302.pdf

  Then do the related modification.

  If you still have issues,share your whole modified project, and your new lcd connection with the sln-viznlc-iot board, then I will help you to check the details, thanks.

Best Regards,

kerry