Skip to main content
q123w123e123qweqwe
Associate III
June 5, 2020
Question

STM32F746 Custom Board Touch Screen Sync issue

  • June 5, 2020
  • 4 replies
  • 1075 views

Hi,

I'm working on a Touch Screen project and using STM32F746 MCU. I have an sync issue I couldn't solved yet. Here is video: https://www.youtube.com/watch?v=0T0yGYekXSE

My LTDC parameters are the same with datasheet I think there is some timing problem but I don't know what to do. Here are datasheet and my LTDC config codes.

Datasheet: https://cdn.ozdisan.com/ETicaret_Dosya/493618_9666178.pdf

LTDC Code:

/* USER CODE END LTDC_Init 1 */
 hltdc.Instance = LTDC;
 hltdc.Init.HSPolarity = LTDC_HSPOLARITY_AH;
 hltdc.Init.VSPolarity = LTDC_VSPOLARITY_AH;
 hltdc.Init.DEPolarity = LTDC_DEPOLARITY_AH;
 hltdc.Init.PCPolarity = LTDC_PCPOLARITY_IPC;
 hltdc.Init.HorizontalSync = 0;
 hltdc.Init.VerticalSync = 0;
 hltdc.Init.AccumulatedHBP = 46;
 hltdc.Init.AccumulatedVBP = 23;
 hltdc.Init.AccumulatedActiveW = 846;
 hltdc.Init.AccumulatedActiveH = 503;
 hltdc.Init.TotalWidth = 1200;
 hltdc.Init.TotalHeigh = 650;
 hltdc.Init.Backcolor.Blue = 0;
 hltdc.Init.Backcolor.Green = 0;
 hltdc.Init.Backcolor.Red = 0;
 if (HAL_LTDC_Init(&hltdc) != HAL_OK)
 {
 Error_Handler();
 }
 pLayerCfg.WindowX0 = 0;
 pLayerCfg.WindowX1 = 800;
 pLayerCfg.WindowY0 = 0;
 pLayerCfg.WindowY1 = 480;
 pLayerCfg.PixelFormat = LTDC_PIXEL_FORMAT_RGB565;
 pLayerCfg.Alpha = 255;
 pLayerCfg.Alpha0 = 0;
 pLayerCfg.BlendingFactor1 = LTDC_BLENDING_FACTOR1_CA;
 pLayerCfg.BlendingFactor2 = LTDC_BLENDING_FACTOR2_CA;
 pLayerCfg.FBStartAdress = 0xC0000000;
 pLayerCfg.ImageWidth = 800;
 pLayerCfg.ImageHeight = 480;
 pLayerCfg.Backcolor.Blue = 0;
 pLayerCfg.Backcolor.Green = 0;
 pLayerCfg.Backcolor.Red = 0;

This topic has been closed for replies.

4 replies

MMoon.1
Visitor II
June 8, 2020

Do you mean the flickering of the display?

q123w123e123qweqwe
Associate III
June 8, 2020

Yes, the flickering.

MMoon.1
Visitor II
June 9, 2020

Have you checked with a scope that you have the expected timings for pixel clock, vsync, hsync