When you write on the screen, you get an afterimage of the screen shaking?

[PKunK.1]

During development on stm32f469i_Discovery, LCD with ILI9806Eic was changed.

There was a problem with LCD display after the change.

Unicode::snprintf(Hour_TimeBuffer, 4, "%02d", mHour_Data);

main_pageView::Hour_Time.invalidate();

On this writing screen, write the changed value on the screen whenever the mHour_Data value is changed.

When writing the changed value, something like an afterimage remains on the LCD screen.

It's a problem that hasn't happened before, but it keeps happening after changing the LCD.

LCD spec is set to Video mode and set to 60 frames. The same problem occurs when set to 40 frames.

I don't know why this problem is happening.

Is it related to the speed used to display data on the LCD and the number of LCD frames?

True! After changing the LCD, the cycle of the Model::tick() function was changed.

Previously, it worked every 17msec, but after changing the LCD, it was developed by 11.stm32f469i_Discovery and changed the LCD with ILI9806Eic.

There was a problem with LCD display after the change.

Unicode::snprintf(Hour_TimeBuffer, 4, "%02d", mHour_Data);

main_pageView::Hour_Time.invalidate();

On this writing screen, write the changed value on the screen whenever the mHour_Data value is changed.

When writing the changed value, something like an afterimage remains on the LCD screen.

It's a problem that hasn't happened before, but it keeps happening after changing the LCD.

LCD spec is set to Video mode and set to 60 frames. The same problem occurs when set to 40 frames.

I don't know why this problem is happening.

Is it related to the speed used to display data on the LCD and the number of LCD frames?

True! After changing the LCD, the cycle of the Model::tick() function was changed.

Previously, it operated every 17msec, but changed to 11.38usec after changing LCD.

Can you check what's wrong with my settings?

[Romain DIELEMAN]

Hi,

​

Could you edit your question ? It is a bit confusing :grinning_face_with_sweat:, so could you maybe rephrase it or clean it of repetitions ?

If I understand it correctly, you are using an STM32F429 discovery board and have changed the display to another ? Have you started your project from scratch or did you use the application template for the STM32F429 disco available in TouchGFX Designer ?

Could you share the datasheet of the display ? In your settings have you made sure all the right pins were set up and updated the clock configuration if relevant ?

/Romain

[PKunK.1]

Development is using the stm32f469i_Discovery board.

The project was created and developed by TouchGFX Designer.

During development, the HW specification was changed, connecting a separate 5-inch LCD to the stm32f469i_Discovery board instead of the stm32f469i_Discovery 4-inch LCD.

The LCD is the KD050FWFIA019-C019A and the controller ic uses the ILI9806E.

The 4-inch LCD of the stm32f469i_Discovery Board is Command with TE, and the 5-inch LCD is Video mode.

The changes in program settings were made to MX_DSIHOST_DSI_Init(), MX_LTD_Init(), and other settings were not changed.

After changing LCD, it seems that the speed of screen switching has also slowed down a lot.

All this seems to be related to the system clock, but it's hard to find which part is the problem.

Please let me know if you need more information.

Upload the requested data sheet as an attachment.

[N. SANTINI]

Hi,

LTDC frequency is not the only thing to be changed if you switch to another display, LTDC timings (vertical/horizontal back/front porches, etc.), must also be adapted to your new display's datasheet (this is not clear if you did so in your description)

This is even more important in DSI Video mode as the timing information will directly come from the LTDC (in DSI Adapted Command mode the display controller handles the display panel timing).

Please be also aware that with this new display 854x480 you have a line of 854 pixels, which is not a multiple of 64 bytes either in 16 or 24 bits, this may lead to the issue described in AN4861, section 4.5.2 and lead to visual artefacts.

I hope this will help you in your investigations,

Best regards,

Nicolas