Black screen when enabling "Debug: Serial Wire"

[JanGlueck]

Hi guys,

I bought a STM32F469I-Disco Board. I have played around with TouchGFX example projects and had success adding an ADC (ADC1_IN9 connected to Pin PB1) conversion to the project and display the value on the touch display as text in a textArea as well as with a gauge.

I use DMA in circular mode and enabled cont. conversion and cont. requests. I use a task and queue in FREERTOS and as I said that part works fine.

Then I wanted to add UART to that project which should prompt a text every second. I chose USART3 because Pins PB10 and PB11 are connected to the virtual COM port of the built-in STLink. I activated Debug serial Wire under System Core / Sys because the tutorial I followed said so. Timebase source is TIM6.

The project compiles without errors. But when I flash the board the screen stays black.

Then I tried to revert erverything regarding UART and Debug Serial Wire (deactivate USART3, disable Debug) but the screen stays black.

Any Ideas? Thanks.

EDIT: The same happens to any other project. E.g. the DiceAnimation Demo in TouchGFX Designer: When I create the project new and flash the board it works just fine. When I then activate Degub: Serial Wire in Sys the screen is black after flashing and the project can not be recovered. Even when I deactive Debug Serial Wire again, the screen is black.

[KDJEM.1]

Hello @JanGlueck and welcome to the community,

Could you try running through the debug and see if the code is stuck in a HAL infinite loop? May be this post can help you: TouchGFX - Serial Wire debug problem.

Thank you.

Kaouthar

[JanGlueck]

Hello Kaouthar,

thank you for looking into this.

I don't have this exact project anymore.

But I run into the same issue quite often: Project compiles without error, flashes, but screen stays black.

I started a blank TouchGFX project with only one screen and only one background image, no text, no button, nothing.

No serial wire debug.

Then I started adding things in CubeIDE: one timer that flashes one user LED (TIM2) and another timer that flashes another user LED (TIM9). That worked fine.

Then I wanted to add a DAC in DMA mode which should generate a sinewave. TIM7 is used to trigger the DAC. But already then I get the black sceen and also the LEDs do not flash. I increased the stack size of the defaultTask from 128 to 2048 but no luck. Then I deactivated the DAC again but I can't get the program to start anymore.

void StartDefaultTask(void *argument)
{
  /* USER CODE BEGIN 5 */

	HAL_TIM_Base_Start_IT(&htim2);
	HAL_TIM_Base_Start_IT(&htim9);
	HAL_TIM_Base_Start_IT(&htim7);

	HAL_DAC_Start_DMA(&hdac,DAC_CHANNEL_1, (uint32_t*) &dma_buffer, 2 * DMA_BUFFER_SIZE, DAC_ALIGN_12B_R);


  /* Infinite loop */
  for(;;)
  {
    osDelay(100);
  }
  /* USER CODE END 5 */
}

Right now, the MX_TouchGFX_Init(); does not finish. See screenshot.

EDIT:

We seem to stop here:

[KDJEM.1]

Hello @JanGlueck,

Thank you for updating this post.

Could you share the STM32F469I-DISCO board revision and the software versions STM32CubeIDE, TouchGFX? Are you using the latest software versions? 

Thank you.

Kaouthar

[JanGlueck]

Hello @KDJEM.1,

CubeIDE Version: 1.17.0

TouchGFX Version: 4.24.1

I always used this board in TouchGFX: 

Disco Board Version:

Thanks,

Jan