HAL_Dalay()是毫秒級(jí)延時(shí)，為了使用微秒級(jí)延時(shí)最近學(xué)習(xí)了一下，總結(jié)如下，推薦使用最后一種方式。

/*

 * 本文件包括四種延時(shí)方式：

 * 1. 原來(lái)的HAL庫(kù)函數(shù)HAL_Delay（）    2. 采用定時(shí)器2設(shè)置延時(shí)函數(shù)     3. 采用系統(tǒng)滴答中斷方式的ms和us級(jí)延時(shí)

 * 4. 采用系統(tǒng)滴答非中斷方式的ms和us級(jí)延時(shí)（在一次計(jì)數(shù)值范圍內(nèi)的延時(shí)）

 */

/* Includes ------------------------------------------------------------------*/

#include "stm32l1xx_hal.h"

#include "tim.h"

#include "usart.h"

#include "gpio.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* Private variables ---------------------------------------------------------*/

volatile unsigned int timenum;      //必須要加volatile?。?！

volatile unsigned long time_delay; // 延時(shí)時(shí)間，注意定義為全局變量

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/

void SystemClock_Config(void);

void Error_Handler(void);

/* USER CODE BEGIN PFP */

/* Private function prototypes -----------------------------------------------*/

HAL_StatusTypeDef delay_10us(uint32_t num);

void delay_us(volatile unsigned long nms);

void delay_ms(volatile unsigned long nms);

void delay_ms2(int32_t nms);

/* USER CODE END PFP */

/* USER CODE BEGIN 0 */

int fputc(int ch, FILE *f)  

{  

HAL_UART_Transmit(&huart2 , (uint8_t *)&ch, 1, 0xFFFF);  

return ch;  

}

/* USER CODE END 0 */

int main(void)

{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

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

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

  HAL_Init();

  /* Configure the system clock */

  SystemClock_Config();

  /* Initialize all configured peripherals */

  MX_GPIO_Init();

  MX_TIM2_Init();

  MX_USART2_UART_Init();

  /* USER CODE BEGIN 2 */

  /*##-1- Start the TIM Base generation in interrupt mode ####################*/

  //HAL_TIM_Base_Start_IT(&htim2);

printf("Testing timer2\n");

HAL_Delay(1000);

printf("Testing timer2\n");

HAL_Delay(1000);

printf("Testing timer2\n");

HAL_Delay(1000);

printf("Testing timer2\n");

HAL_Delay(1000);

printf("Testing timer2\n");

  /* USER CODE END 2 */

  /* Infinite loop */

  /* USER CODE BEGIN WHILE */

  while (1)

  {

  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */

//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_RESET);

delay_ms2(500);

printf("12\n");

//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_SET);

//delay_us(500000);

  }

  /* USER CODE END 3 */

}

/** System Clock Configuration

*/

void SystemClock_Config(void)

{

  RCC_OscInitTypeDef RCC_OscInitStruct;

  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  __HAL_RCC_PWR_CLK_ENABLE();

  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  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.PLLMUL = RCC_PLL_MUL12;

  RCC_OscInitStruct.PLL.PLLDIV = RCC_PLL_DIV3;

  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)

  {

    Error_Handler();

  }

  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_DIV1;

  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)

  {

    Error_Handler();

  }

  HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_1);

  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);  //注意這里HAL庫(kù)重裝了系統(tǒng)計(jì)數(shù)器的值，使美1ms中斷一次??！

  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  /* SysTick_IRQn interrupt configuration */

  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);

}

/* USER CODE BEGIN 4 */

/**

  * @brief  Period elapsed callback in non blocking mode

  * @param  htim: TIM handle

  * @retval None

  */

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)//定時(shí)器2中斷處理函數(shù)

{

    if (htim->Instance == htim2.Instance)

    {

HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_8);

if(timenum)

{

timenum--;

//printf("%d\n", timenum);

}

    }

}

HAL_StatusTypeDef delay_10us(uint32_t num)//自定義的定時(shí)器2實(shí)現(xiàn)延時(shí)的函數(shù)

{

timenum = num;

HAL_TIM_Base_Start_IT(&htim2);

while(timenum) //為什么一直停在這個(gè)循環(huán)中？？？3-2-1-2-3……怎么會(huì)這樣?。。?-volatile！

;

HAL_TIM_Base_Stop_IT(&htim2);

return HAL_OK;

}

//SysTick實(shí)現(xiàn)延時(shí)n_ms，中斷方式

void delay_ms(volatile unsigned long nms)

{

    //SYSTICK分頻--1ms的系統(tǒng)時(shí)鐘中斷

    if (SysTick_Config(HAL_RCC_GetHCLKFreq()/1000))

    {

        while (1);

    }

    time_delay=nms;//讀取定時(shí)時(shí)間

    while(time_delay);

    SysTick->CTRL=0x00; //關(guān)閉計(jì)數(shù)器

    SysTick->VAL =0X00; //清空計(jì)數(shù)器

}

//SysTick實(shí)現(xiàn)延時(shí)n_us，中斷方式

void delay_us(volatile unsigned long nus)

{

 //SYSTICK分頻--1us的系統(tǒng)時(shí)鐘中斷

    if (SysTick_Config(HAL_RCC_GetHCLKFreq()/1000000))

    {

        while (1);

    }

    time_delay=nus;//讀取定時(shí)時(shí)間

    while(time_delay);

    SysTick->CTRL=0x00; //關(guān)閉計(jì)數(shù)器

    SysTick->VAL =0X00; //清空計(jì)數(shù)器

}

//SysTick實(shí)現(xiàn)延時(shí)中斷方式的中斷處理函數(shù)

//在中斷中將time_delay遞減。實(shí)現(xiàn)延時(shí)

//void SysTick_Handler(void)

//{

//    if(time_delay)

//        time_delay--;

//}

//void HAL_SYSTICK_Callback(void)//原cube HAL庫(kù)中中斷處理回調(diào)函數(shù)重寫

//{

// if(time_delay)

// time_delay--;

//}

//void HAL_IncTick(void)//原cube HAL庫(kù)中，重寫

//{

// if(time_delay)

// time_delay--;

//}

/********************************* 優(yōu)選的方式 ***********************************************************************/

/*一次填充系統(tǒng)計(jì)時(shí)器以實(shí)現(xiàn)非中斷延遲，受限系統(tǒng)計(jì)時(shí)器stmtick只有24位，所以最長(zhǎng)計(jì)時(shí)有所限制*/

void delay_ms2(int32_t nms)

{

 int32_t temp;

 SysTick->LOAD = 8000*nms;

 SysTick->VAL=0X00;//清空計(jì)數(shù)器

 SysTick->CTRL=0X01;//使能，減到零是無(wú)動(dòng)作，采用外部時(shí)鐘源

 do

 {

  temp=SysTick->CTRL;//讀取當(dāng)前倒計(jì)數(shù)值

 }while((temp&0x01)&&(!(temp&(1<<16))));//等待時(shí)間到達(dá)

    SysTick->CTRL=0x00; //關(guān)閉計(jì)數(shù)器

    SysTick->VAL =0X00; //清空計(jì)數(shù)器

}

/* USER CODE END 4 */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

/*********************************************************************************************************************/

/*********************************************************************************************************************/

/*********************************************************************************************************************/

/*如果自寫系統(tǒng)時(shí)鐘中斷處理函數(shù)，需要在stml1xx_it.c中注釋掉一下函數(shù)*/

/**

* @brief This function handles System tick timer.

*/

#if 1

void SysTick_Handler(void)

{

  /* USER CODE BEGIN SysTick_IRQn 0 */

  /* USER CODE END SysTick_IRQn 0 */

  HAL_IncTick();

  HAL_SYSTICK_IRQHandler();

  /* USER CODE BEGIN SysTick_IRQn 1 */

  /* USER CODE END SysTick_IRQn 1 */

}

#endif