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How setup LTDC to DE MODE

uilter
Senior

Hi,

My MCU is a STM32H753BIT6. This is a custom board that works fine with SYNC-MODE displays types.

I have a new display only works in DE MODE. It not requires the HSYNC or VSYNC signals.

Is there any way to configure LTDC peripheral and TouchGFX to work only in DE MODE? This is a communication image about this mode.


_legacyfs_online_stmicro_images_0693W00000bVejGQAS.png 

I disconnect physically the VSYNC/HSYNC signals and ground it to make sure.

Thanks for any tip and help!

19 REPLIES 19

Hi @Community member​ 

Thanks fot your comment.

When you sad "put the value 1 for each i-e VSync =1 & HSync = 1 in CubeMX" is set the polarity in LTDC configuration to Active HIGH or set the GPIOs to output and config it to HIGH state?

Thanks.

In this custom board I also is with another two displays:

  • 7inch 1024X600
  • 10.1inch 1024X600

Next step I will design a RGB->LVDS bridge to a bigger display with high resolution (1280x800).

In another custom board I put a RGB->HDMI bridge. I not test it yet.

ktrofimo
Senior III

About 10 years ago I have tested RGB->HDMI bridge (I believe it was from TI) and it was working fine in HD mode (720p) because STM32F429 was too slow for FHD (1080p). But RGB->CVBS (Analog Devices, composite TV) bridge test failed because I was unable to output 27MHz clock (doubled and sync'ed with pixelclock 13,5MHz)

FYI

I'm using the TFP410PAP from TI for RGB-HDMI bridge.

Hi

my experience is ....

You can't disable the LTDC essential signals and set as gpio output , if you do so then whole LTDC becomes inactive in cubemx.

 

The Vsync & Hsync signals can be disabled by putting value 1 for each , as I mentioned before and practically observed.

 

BTW .. my most recent TouchGFX experiment with custom designed board is across STM32H745XIT6 Core board with 1024X600 Chinese TFT .

INaee1_0-1687543529986.jpeg

INaee1_1-1687543529991.jpeg

The above board is with multiple communication protocols . and this customized board is based on following Core Board.

 H9f2461e93d6d46a2b2c3b57bd4dd4faaw.jpg_640x640Q9.jpg

I also implemented Modbus Master RTU with TouchGFX on my previous development board.

Simulated the Modbus values from ModBusSlave utility on laptop and observed values on TouchGFX in numeric figures , custom guages & vertical bars.

 

 

thanks

 

 

Hi ..

Here is TouchGFX running on HP S1932 18.5" Monitor's LVDS LCD with 1366x768 resolution .

The lcd part no. is LTM185AT04 or Equivalent . The driver is stm32f429i-discovery + sn75lvds83b  


_legacyfs_online_stmicro_images_0693W00000dDV59QAG.png
_legacyfs_online_stmicro_images_0693W00000dDUzSQAW.pngBTW ,, I tested ThinkPad T400 TFT 1280x800 resolution with my RGB>LVDS and working fine.

@uilter Can you share the image that has settings modified ...image is empty for viewing so else can you post configure here...it would be helpful thanks

The solution that you posted is showing up as the following in ST Community:

ChipCurious_1-1699493314239.png

Is there a way to post the solution in a way that is visible.

Thanks!

Hi! 
I'm encountering a similar issue, and unfortunately, I can't view the attached screenshot.
Could you please re-upload it and provide written instructions on what steps I should take?

Thank you

Shashikant_Hiremath
Associate III

I tried adjusting display settings and display works!.