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No output coming from one of the LTDC pins of STM32F429

anoopkumar
Associate
Posted on January 25, 2016 at 06:21

Hi ,

I have configured LTDC pins as follows.

/* Enable the LTDC and DMA2D clocks */

__LTDC_CLK_ENABLE();

__DMA2D_CLK_ENABLE();

/* Enable GPIOs clock */

LTDC_GPIO_CLK_EN;

/*** LTDC Pins configuration ***/

GPIO_Init_Structure.Mode      = GPIO_MODE_AF_PP;

GPIO_Init_Structure.Pull      = GPIO_NOPULL;

GPIO_Init_Structure.Speed     = GPIO_SPEED_FAST;

GPIO_Init_Structure.Alternate = GPIO_AF14_LTDC;

GPIO_Init_Structure.Pin       = LCD_DATA_PINS_1;

HAL_GPIO_Init(LCD_DATA_PORT_1, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin       = LCD_DATA_PINS_2;

HAL_GPIO_Init(LCD_DATA_PORT_2, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin       = LCD_DATA_PINS_3;

HAL_GPIO_Init(LCD_DATA_PORT_3, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin       = LCD_DATA_PINS_4;

HAL_GPIO_Init(LCD_DATA_PORT_4, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin       = LCD_DATA_PINS_5;

HAL_GPIO_Init(LCD_DATA_PORT_5, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin                         =       LCD_HSYNC_PIN;

HAL_GPIO_Init(LCD_HSYNC_PORT, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin                         =       LCD_VSYNC_PIN;

HAL_GPIO_Init(LCD_VSYNC_PORT, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin                         =       LCD_MODE_PIN;

HAL_GPIO_Init(LCD_MODE_PORT, &GPIO_Init_Structure);

GPIO_Init_Structure.Pin                         =       LCD_CLK_PIN;

HAL_GPIO_Init(LCD_CLK_PORT, &GPIO_Init_Structure);

But I found that in one of the pins, data is not coming properly when I checked in oscilloscope. 

(LCD_DATA_PINS_4)

&sharpdefine LCD_DATA_PORT_4         GPIOB

&sharpdefine LCD_DATA_PINS_4         GPIO_PIN_1

I tried to configure the same pins are GPIO and was able to change the pin conditions through debugger.

Why is this problem happening?

Is this because of the way I configured LTDC? 

Data signal is active in all the other pins . 

Connections are tested for continuity.

              

#stm32f429-ltdc-2-layer-lcd-tft
1 REPLY 1
anoopkumar
Associate
Posted on January 25, 2016 at 08:55

Problem was due to incorrectly configured pin (alternate function).

Now it is fixed.

Thanks,

Anoop