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Getting wring color when testing LTDC !!

MMoha.4
Associate II

‎2022-06-11 11:20 AM

Hello,

I am testing the LTDC on a dev board. The strange thing is i am getting the wrong color at initialization.

Below is the code for initialzation of LTDC. I get red when i try to fill with blue, and red when i try to fill with blue. Thesre is half word swap heppening somwhere but i cant notice it.

Please advise.

=================================================================

Labels:
Prj2_LTDC.rar
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3 REPLIES 3
MMoha.4
Associate II

‎2022-06-11 11:23 AM

Below is the initialization code :

static uint16_t frame_buffer[320 * 240];

LTDC_HandleTypeDef hltdc;

static uint16_t *ptr_ltdc_draw_buffer;

static void ltdc_low_level_init(void);

void ltdc_init(void)

{

 /* Low level initialization */

 ltdc_low_level_init();

 /* Fill screen with Blue */

 for (int i = 0; i < (320 * 240); i++)

 {

  frame_buffer[i] = 0x001F;

 }

 /* */

 hltdc.Instance        = LTDC;

 hltdc.Init.HSPolarity     = LTDC_HSPOLARITY_AL;

 hltdc.Init.VSPolarity     = LTDC_VSPOLARITY_AL;

 hltdc.Init.DEPolarity     = LTDC_DEPOLARITY_AL;

 hltdc.Init.PCPolarity     = LTDC_PCPOLARITY_IIPC;

 hltdc.Init.HorizontalSync   = 3;

 hltdc.Init.VerticalSync    = 3;

 hltdc.Init.AccumulatedHBP   = 46;

 hltdc.Init.AccumulatedVBP   = 15;

 hltdc.Init.AccumulatedActiveW = 366;

 hltdc.Init.AccumulatedActiveH = 255;

 hltdc.Init.TotalWidth     = 374;

 hltdc.Init.TotalHeigh     = 257;

 hltdc.Init.Backcolor.Blue   = 255;

 hltdc.Init.Backcolor.Green  = 0;

 hltdc.Init.Backcolor.Red   = 0;

 /* */

 if (HAL_LTDC_Init(&hltdc) != HAL_OK)

 {

  Error_Handler();

 }

 LTDC_LayerCfgTypeDef pLayerCfg = {0};

 /* */

 pLayerCfg.WindowX0      = 0;

 pLayerCfg.WindowX1      = 320;

 pLayerCfg.WindowY0      = 0;

 pLayerCfg.WindowY1      = 240;

 pLayerCfg.PixelFormat     = LTDC_PIXEL_FORMAT_RGB565;

 pLayerCfg.Alpha        = 255;

 pLayerCfg.Alpha0       = 225;

 pLayerCfg.BlendingFactor1   = LTDC_BLENDING_FACTOR1_CA;

 pLayerCfg.BlendingFactor2   = LTDC_BLENDING_FACTOR2_CA;

 pLayerCfg.FBStartAdress    = (uint32_t) ptr_ltdc_draw_buffer;

 pLayerCfg.ImageWidth     = 320;

 pLayerCfg.ImageHeight     = 240;

 pLayerCfg.Backcolor.Blue   = 255;

 pLayerCfg.Backcolor.Green   = 0;

 pLayerCfg.Backcolor.Red    = 0;

 /* */

 if (HAL_LTDC_ConfigLayer(&hltdc, &pLayerCfg, 0) != HAL_OK)

 {

  Error_Handler();

 }

}

/**

 * @brief Private function template.

 * @note  Note 1.

 * @param pram1 description of param1.

 * @param pram2 description of param1.

 * @retval Return description

 */

static void ltdc_low_level_init(void)

{

 GPIO_InitTypeDef GPIO_InitStruct = {0};

 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

 /*

  * Initializes the peripherals clock

  */

 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LTDC;

 PeriphClkInitStruct.PLL3.PLL3M = 6;

 PeriphClkInitStruct.PLL3.PLL3N = 129;

 PeriphClkInitStruct.PLL3.PLL3P = 2;

 PeriphClkInitStruct.PLL3.PLL3Q = 2;

 PeriphClkInitStruct.PLL3.PLL3R = 53;

 PeriphClkInitStruct.PLL3.PLL3RGE = RCC_PLL3VCIRANGE_1;

 PeriphClkInitStruct.PLL3.PLL3VCOSEL = RCC_PLL3VCOWIDE;

 PeriphClkInitStruct.PLL3.PLL3FRACN = 0;

 if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)

 {

  Error_Handler();

 }

 /* LTDC clock enable */

 __HAL_RCC_LTDC_CLK_ENABLE();

 /* GPIO clock enable */

 __HAL_RCC_GPIOA_CLK_ENABLE();

 __HAL_RCC_GPIOB_CLK_ENABLE();

 __HAL_RCC_GPIOE_CLK_ENABLE();

 __HAL_RCC_GPIOC_CLK_ENABLE();

 __HAL_RCC_GPIOD_CLK_ENABLE();

 /*

 LTDC GPIO Configuration :

 PA1   ------> LTDC_R2

 PB0   ------> LTDC_R3

 PA11  ------> LTDC_R4

 PA9   ------> LTDC_R5

 PB1   ------> LTDC_R6

 PE15  ------> LTDC_R7

 PD6   ------> LTDC_B2

 PA8   ------> LTDC_B3

 PE12  ------> LTDC_B4

 PA3   ------> LTDC_B5

 PB8   ------> LTDC_B6

 PB9   ------> LTDC_B7

 PA6   ------> LTDC_G2

 PE11  ------> LTDC_G3

 PB10  ------> LTDC_G4

 PB11  ------> LTDC_G5

 PC7   ------> LTDC_G6

 PD3   ------> LTDC_G7

 PA4   ------> LTDC_VSYNC

 PE13   ------> LTDC_DE

 PE14   ------> LTDC_CLK

 PC6   ------> LTDC_HSYNC

 */

 GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_6

            |GPIO_PIN_9|USB_DFU_DM___LTDC_R4_Pin;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF14_LTDC;

 HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF9_LTDC;

 HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14

            |GPIO_PIN_15;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF14_LTDC;

 HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_8|GPIO_PIN_9;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF14_LTDC;

 HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF14_LTDC;

 HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_8;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF13_LTDC;

 HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

 GPIO_InitStruct.Pin = GPIO_PIN_3|GPIO_PIN_6;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF14_LTDC;

 HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

}

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MM..1
Chief III

‎2022-06-12 01:58 AM

You miss as first use code snip

static uint16_t frame_buffer[320 * 240];
LTDC_HandleTypeDef hltdc;
 
static uint16_t *ptr_ltdc_draw_buffer;
static void ltdc_low_level_init(void);
 
void ltdc_init(void)
{
 /* Low level initialization */
ltdc_low_level_init();
 
 /* Fill screen with Blue */
 for (int i = 0; i < (320 * 240); i++)
 {
  frame_buffer[i] = 0x001F;
 }

as second your LCD need config controller registers where is set mode BGR or RGB ...

Too where you set ?

pLayerCfg.FBStartAdress    = (uint32_t) ptr_ltdc_draw_buffer;

why you dont use simply frame_buffer here ...

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MMoha.4
Associate II
In response to MM..1

‎2022-06-12 03:06 PM

thank you for replying ... i solved teh issue by swaping RGB to BGR on the TFT dispaly controler side ... using SPI comands

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