stm32h743 Timer2 or whatever timer capture with external clock

[aatom]

This is driving me crazy, whay timers on STM32 are so complicated and no normal information / datasheets etc, how to use.

Timer2 is working (external clock), Timer interrupt (TIM_IT_UPDATE) also working, but not capture interrupt. And signal is also present on capture pin, when I manually write capturing code without timer inside main() thread, then it's working. And if I check premade HAL code, there is no timer starting function to enable capture interrupt, just only update interrupt.

So my initial code:

static void MX_TIM2_Init(void)
{

  /* USER CODE BEGIN TIM2_Init 0 */

  /* USER CODE END TIM2_Init 0 */

  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_IC_InitTypeDef sConfigIC = {0};

  /* USER CODE BEGIN TIM2_Init 1 */

  /* USER CODE END TIM2_Init 1 */
  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 0;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 4294967295;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_ETRMODE2;
  sClockSourceConfig.ClockPolarity = TIM_CLOCKPOLARITY_NONINVERTED;
  sClockSourceConfig.ClockPrescaler = TIM_CLOCKPRESCALER_DIV1;
  sClockSourceConfig.ClockFilter = 0;
  if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_IC_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
  sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
  sConfigIC.ICFilter = 0;
  if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_4) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN TIM2_Init 2 */
  htim2.IC_CaptureCallback =  User_TIM2_IC_CaptureCallback;
  htim2.PeriodElapsedCallback =  User_TIM2_IC_CaptureCallback; // TESTING
  /* USER CODE END TIM2_Init 2 */

}

Interrupt tread:

void User_TIM2_IC_CaptureCallback(TIM_HandleTypeDef *htim) {
    //if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_4)
	{
        Line++; //TESTING
    }
}

And how I start timer before main() while(1) { ...

htim2.State = HAL_TIM_STATE_BUSY;
  __HAL_TIM_ENABLE_IT(&htim2, TIM_IT_CC4);
  __HAL_TIM_ENABLE(&htim2);

More, I test now this way, that I use internal clock, then promt capture starts working. So finally how can I use timer capture with external clock (what is major in my solution, slave mode by external clock also doesn't work).

[TDK]

The Reference Manual goes into great depth to describe each feature of the timer.

https://www.st.com/resource/en/reference_manual/rm0433-stm32h742-stm32h743753-and-stm32h750-value-line-advanced-armbased-32bit-mcus-stmicroelectronics.pdf

There are also many different working example projects that show various features of the timer. Here is one for input catpure:

https://github.com/STMicroelectronics/STM32CubeH7/tree/master/Projects/NUCLEO-H743ZI/Examples/TIM/TIM_InputCapture

It's unclear what you're trying to do here specifically. Do you have an external clock and you're trying to do input capture on a separate pin? External vs internal clock setup is independent of input capture on a channel.

Look at the various HAL_TIM_* function calls in the example to see how to use them.

[aatom]

At moment I don't get to work 2M parallel camera on STM32H753I-EVAL (on EVAL there is no camera interface, I connect to big connectors / STM32H753I pins) and like to check camera signals, so CLK timer input and LF (horisontal timing) capture, so I can see, how stable signal is and colums count.

But it's doesn't matter, there is more solutions, what can need precise (external clock) time meansurings.

I have read Reference Manual many times and sorry, its not "great depth":

* What is Timer internal input frequency, on clock configuration, there is APB1 / APB2 Timer clocks, what is what

* Trigger controller / Slave controller / Encoder interface is just like black box, no good explanation

* StmCubeMx configuration and Reference Manual don't match, example on manual "External clock mode1: external input pin (TIx)" , but on Reference Manual timer block diagram there is TIMx_ETR and same on StmCubeMx.

* ITR input detailed explanation

... and this is just begginning

Github example also don't help, because uses internal clock and StmCubeMx generates different code.

[TDK]

> What is Timer internal input frequency, on clock configuration, there is APB1 / APB2 Timer clocks, what is what

The clock tree in CubeMX provides a good visualization. Have you looked at it? The RM also goes into great detail about this.

> Trigger controller / Slave controller / Encoder interface is just like black box, no good explanation

Did you read this section? What is unclear? Only a partial screenshot.

Maybe you're mistaking the datasheet for the reference manual.

[aatom]

I don't want to start an argument, but RM, configuring the module with Cube_MX and the generated HAL_ code are just confusing. Looking at the registers, how CUBE_MX was configured, helped me to find the solution. And it wasn't that it worked with the internal clock, not with the external one, but that things suddenly work, then not (without me having found the solution yet).

The solution and the answer I was expecting is very simple, TIM2 capture on CH4 must be started with the line:
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_4);

[TDK · Accepted solution]

Yeah, the RM has no knowledge of HAL, so if you're looking to use HAL, best to rely on CubeMX examples or HAL documentation instead. But if you want to know how the chip works at the register level, the RM is the best source.