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glitch on Scrollable Container with list layout

MPast.1
Senior II

‎2025-02-13 2:38 PM

Hi everybody,

I have some screens where is present a scrollable container and listLayout like child to generale a scrollable list (in other words a vertical menu) (see the video).

Everytime I scroll Up e Down the container a glitch compare in the middle of screen like a horizontal black line.

The project has a lot of screen but I don't have any other problems with transictions or other objects.

Only with scroll container in every page their are present..

I'm using a custom board with an STM32H743VIT6 and a 16bit RGB display. connected on LTDC.

(all graphic assets are placed into an external QSPI memory )

I tried to disable DMA2D, Dcache, I change the clock of LTDC  but without success.

 

Does someone has some ideas? some suggestion?

Thanks in advance

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4 REPLIES 4
MPast.1
Senior II

‎2025-03-04 3:29 AM

I solved this problem: is not a problem caused by TouchGFX,LTDC or STM32.

It was caused by a "***" LCD that require a lot of parameters to manage it: some of them was setted wrong by myself.

After the correction everything works perfectly.

0 Kudos
ferro
Lead
In response to MPast.1

‎2025-03-04 6:59 AM

Hi @MPast.1 

 

"After the correction everything works perfectly."

Could you possible share what (combination of) parameters were to blame ? I am observing a similar glitch on my display.

 

Thanks

0 Kudos
MPast.1
Senior II
In response to ferro

‎2025-03-05 11:34 AM

My project is composed a display that has st7796 controller. This display (with integrated controlled) by default start working on SPI and not on RGB parallel lines.

So I need to

the original init:

	// Command Set Control - enable command 2 part I
	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0xC3);
	// Command Set Control - enable command 2 part II
	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x96);

	// Interface Mode Control
	LCD_IO_WriteCmd(ST7796_IFMODE);
	LCD_IO_WriteData(0x82);

	// Display Inversion Control
	LCD_IO_WriteCmd(ST7796_INVCTR);
	LCD_IO_WriteData(0x01);


	// Display Function Control
	LCD_IO_WriteCmd(ST7796_DFUNCTR);
	LCD_IO_WriteData(0x20);
	LCD_IO_WriteData(0x02);
	LCD_IO_WriteData(0x3B);
	
	
	if (Orientation == PORTRAIT_0)			// display TOP = NTC probe Side
	{
		GT911.Orientation = PORTRAIT_0;
		LCD_IO_WriteCmd(ST7796_MADCTL);
		LCD_IO_WriteData(0x48);				//48
	}

	if (Orientation == PORTRAIT_180)			// display TOP = smartcard side
	{
		GT911.Orientation = PORTRAIT_180;
		LCD_IO_WriteCmd(ST7796_MADCTL);
		LCD_IO_WriteData(0x88);
	}

//	// Display Function Control
//	LCD_IO_WriteCmd(ST7796_BPC);
//	LCD_IO_WriteData(0x0D);		// vertical front porch period
//	LCD_IO_WriteData(0x04);		// vertical back porch period
//	LCD_IO_WriteData(0x00);
//	LCD_IO_WriteData(0x1E);		// horizontal back porch period (30pixel)


//	//Power Control 1
//	LCD_IO_WriteCmd(ST7796_PWCTR1);
//	LCD_IO_WriteData(0xF0);
//	LCD_IO_WriteData(0x35);
//
//	// Power Control 2
//	LCD_IO_WriteCmd(ST7796_PWCTR2);
//	LCD_IO_WriteData(0x15);

	// Power Control 3
	LCD_IO_WriteCmd(ST7796_PWCTR3);
	LCD_IO_WriteData(0xA7);

//	LCD_IO_WriteCmd(0xC3);
//	LCD_IO_WriteData(0x09);

	// VCOM Control
	LCD_IO_WriteCmd(ST7796_VMCTR1);
	LCD_IO_WriteData(0x25);

	// Vcom Offset Register
	LCD_IO_WriteCmd(ST7796_VCM);
	LCD_IO_WriteData(0x00);


	// negative gamma control
	LCD_IO_WriteCmd(0xE8);
	LCD_IO_WriteData(0x40);
	LCD_IO_WriteData(0x82);
	LCD_IO_WriteData(0x07);
	LCD_IO_WriteData(0x18);
	LCD_IO_WriteData(0x27);
	LCD_IO_WriteData(0x0a);
	LCD_IO_WriteData(0xb6);
	LCD_IO_WriteData(0x33);

	// positive gamma control
	LCD_IO_WriteCmd(ST7796_GMCTRP1);	//0xE0
	LCD_IO_WriteData(0xD0);
	LCD_IO_WriteData(0x04);
	LCD_IO_WriteData(0x0D);
	LCD_IO_WriteData(0x11);
	LCD_IO_WriteData(0x13);
	LCD_IO_WriteData(0x2B);
	LCD_IO_WriteData(0x3F);
	LCD_IO_WriteData(0x54);
	LCD_IO_WriteData(0x4C);
	LCD_IO_WriteData(0x18);
	LCD_IO_WriteData(0x0D);
	LCD_IO_WriteData(0x0B);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x23);

	// negative gamma control
	LCD_IO_WriteCmd(ST7796_GMCTRN1);	//0xE1
	LCD_IO_WriteData(0xD0);
	LCD_IO_WriteData(0x04);
	LCD_IO_WriteData(0x0C);
	LCD_IO_WriteData(0x11);
	LCD_IO_WriteData(0x13);
	LCD_IO_WriteData(0x2C);
	LCD_IO_WriteData(0x3F);
	LCD_IO_WriteData(0x44);
	LCD_IO_WriteData(0x51);
	LCD_IO_WriteData(0x2F);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x20);
	LCD_IO_WriteData(0x23);

	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x3C);

	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x69);

 

the final init:

        // Command Set Control - enable command 2 part I
	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0xC3);

	// Command Set Control - enable command 2 part II
	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x96);

	if (Orientation == PORTRAIT_0)			
	{
	        GT911.Orientation = PORTRAIT_0;
		LCD_IO_WriteCmd(ST7796_MADCTL);
		LCD_IO_WriteData(0x5C);				
	}

	if (Orientation == PORTRAIT_180)		
	{
		GT911.Orientation = PORTRAIT_180;
		LCD_IO_WriteCmd(ST7796_MADCTL);
		LCD_IO_WriteData(0x48);
	}

	LCD_IO_WriteCmd(ST7796_FRMCTR1);
	LCD_IO_WriteData(0x82);

	// Interface Mode Control
	LCD_IO_WriteCmd(ST7796_IFMODE);
	LCD_IO_WriteData(0x82);

	// Display Inversion Control
	LCD_IO_WriteCmd(ST7796_INVCTR);
	LCD_IO_WriteData(0x00);


	// Display Function Control
	LCD_IO_WriteCmd(ST7796_DFUNCTR);
	LCD_IO_WriteData(0xA0);
	LCD_IO_WriteData(0x60); //0x02
	LCD_IO_WriteData(0x3B);
	
	// Power Control 3
	LCD_IO_WriteCmd(ST7796_PWCTR3);
	LCD_IO_WriteData(0xA7);

	// VCOM Control
	LCD_IO_WriteCmd(ST7796_VMCTR1);
	LCD_IO_WriteData(0x25);

	// Vcom Offset Register
	LCD_IO_WriteCmd(ST7796_VCM);
	LCD_IO_WriteData(0x00);


	// Display Output Ctrl Adjust
	LCD_IO_WriteCmd(0xE8);
	LCD_IO_WriteData(0x40);
	LCD_IO_WriteData(0x8A);
	LCD_IO_WriteData(0x00);
	LCD_IO_WriteData(0x00);
	LCD_IO_WriteData(0x29);
	LCD_IO_WriteData(0x19);
	LCD_IO_WriteData(0xA5);
	LCD_IO_WriteData(0x33);

	// positive gamma control
	LCD_IO_WriteCmd(ST7796_GMCTRP1);	//0xE0
	LCD_IO_WriteData(0xD0);
	LCD_IO_WriteData(0x04);
	LCD_IO_WriteData(0x0D);
	LCD_IO_WriteData(0x11);
	LCD_IO_WriteData(0x13);
	LCD_IO_WriteData(0x2B);
	LCD_IO_WriteData(0x3F);
	LCD_IO_WriteData(0x54);
	LCD_IO_WriteData(0x4C);
	LCD_IO_WriteData(0x18);
	LCD_IO_WriteData(0x0D);
	LCD_IO_WriteData(0x0B);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x23);

	// negative gamma control
	LCD_IO_WriteCmd(ST7796_GMCTRN1);	//0xE1
	LCD_IO_WriteData(0xD0);
	LCD_IO_WriteData(0x04);
	LCD_IO_WriteData(0x0C);
	LCD_IO_WriteData(0x11);
	LCD_IO_WriteData(0x13);
	LCD_IO_WriteData(0x2C);
	LCD_IO_WriteData(0x3F);
	LCD_IO_WriteData(0x44);
	LCD_IO_WriteData(0x51);
	LCD_IO_WriteData(0x2F);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x1F);
	LCD_IO_WriteData(0x20);
	LCD_IO_WriteData(0x23);





	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x3C);

	LCD_IO_WriteCmd(ST7796_CSCON);
	LCD_IO_WriteData(0x69);

 

the big problem was :

// Display Function Control
	LCD_IO_WriteCmd(ST7796_DFUNCTR);
	LCD_IO_WriteData(0x20);
	LCD_IO_WriteData(0x02);
	LCD_IO_WriteData(0x3B);

the data generated by LTDC was sent to internal ST7796 controller registers instead of sent to display directly. This problem caused glitches: the original mode was not fast enough

 

 

 

farukisiker
Associate II

‎2025-03-06 1:28 AM

Making container cachable can increase performance. And, do not forget clear cache area if you are using MPU.

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