understanding the logic of timer delay in STM32F407

Thread Starter

yef smith

Joined Aug 2, 2020
498
Hello Mr chips,
yes i did it with
RCC->APB1ENR|=RCC_APB1ENR_TIM4EN;
but the whole problem is with the delay function how are going to know what is the the problem if we delete the call to it?
Thanks.
 

MrChips

Joined Oct 2, 2009
28,552
We need to test one thing at a time.
Ignore the delay( ) for now because this is confusing the issue. You need to get TIM4 working properly first and be able to confirm that it is working.

RCC->APB1ENR|=RCC_APB1ENR_TIM4EN;
This instruction enables the system clock to the timer module. Yes, that has been done.

What you need to do is get the timer to start incrementing.
You do this by setting the CEN bit to 1 in the TIM4->CR1 register.
 

Thread Starter

yef smith

Joined Aug 2, 2020
498
Hello Mr.Chips,I think myticks is incrimenting because we have a gpio toggling on the IRQ function
its being called over and over.
now i am trying to learn how to do debuging using PRINTF
so i could see the value of myticks inside delay.i will update with the results as soon as possible.
The full updated code is shown bellow.
If you see some critical fault ill be happy to know.
Thanks.

Code:
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include <stdio.h>
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
DAC_HandleTypeDef hdac;
unsigned long myticks=0;
/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DAC_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
    void delay(unsigned long us)
    {
        
        TIM4->CR1|=TIM_CR1_CEN;
              myticks=0;
        while(myticks<us)
                {
                 printf("hello+%lu",myticks);   
                }
                        
        TIM4->CR1&=~TIM_CR1_CEN;
      
    }
void TIM4_IRQHandler(void)
{
    myticks++;
    
    HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_12);
  TIM4->SR&=~TIM_SR_UIF;
}   
    
int main(void)
{
    RCC->APB1ENR|=RCC_APB1ENR_TIM4EN;
    TIM4->PSC=0;
    TIM4->ARR=21;
    TIM4->CR1|=TIM_CR1_URS;
    TIM4->DIER|=TIM_DIER_UIE;
    TIM4->EGR=TIM_EGR_UG;

    NVIC_EnableIRQ(TIM4_IRQn);
    
    
    
    
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DAC_Init();
  /* USER CODE BEGIN 2 */
HAL_DAC_Start(&hdac,DAC_CHANNEL_1);
HAL_DAC_SetValue(&hdac,DAC_CHANNEL_1,DAC_ALIGN_12B_R,1365);


  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
      
    
  while (1)
  {
        delay(5000000);
    HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_15);
        HAL_Delay(500);
        // delay(5000000);
        HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_15);
        //delay(5000000);
        HAL_Delay(500);
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 168;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV8;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief DAC Initialization Function
  * @param None
  * @retval None
  */
static void MX_DAC_Init(void)
{

  /* USER CODE BEGIN DAC_Init 0 */

  /* USER CODE END DAC_Init 0 */

  DAC_ChannelConfTypeDef sConfig = {0};

  /* USER CODE BEGIN DAC_Init 1 */

  /* USER CODE END DAC_Init 1 */
  /** DAC Initialization
  */
  hdac.Instance = DAC;
  if (HAL_DAC_Init(&hdac) != HAL_OK)
  {
    Error_Handler();
  }
  /** DAC channel OUT1 config
  */
  sConfig.DAC_Trigger = DAC_TRIGGER_NONE;
  sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
  if (HAL_DAC_ConfigChannel(&hdac, &sConfig, DAC_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN DAC_Init 2 */

  /* USER CODE END DAC_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA0 */
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pins : PD12 PD13 PD14 PD15 */
  GPIO_InitStruct.Pin = GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
 

MrChips

Joined Oct 2, 2009
28,552
There you go again. You are jumping to a new problem without fixing the first one.
Get the GPIO output to the oscilloscope from PD12 working correctly before trying anything else.

Don't give up. I can help you get this working.
 

MrChips

Joined Oct 2, 2009
28,552
Your main( ) code should look something like this:
C:
void main(void)
{
    TIM4_Init();
    GPIO_Init();
    HAL_Init();
    while(1);
}
 

MrChips

Joined Oct 2, 2009
28,552
Test TIM4 interrupts with something like this:
C:
void TIM4_IRQHandler(void)
{
   myticks++;
   HAL_GPIO_TogglePin(GPIOD, GPIO_PIN12);
   TIM4->SR = 0;
}
 

MrChips

Joined Oct 2, 2009
28,552
Initialize TIM4 as follows:
C:
void TIM4_Init(void)
{
    RCC->APB1ENR |= RCC_APB1ENR_TIM4EN;
    TIM4->PSC = 0;
    TIM4->ARR = 1000;
    TIM4->DIER |= TIM_DIER_UIE;
    TIM4->CR1 |= TIM_CR1_CEN;
    NVIC_EnableIRQ(TIM4_IRQn);
}
 
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