stm32CubeMX HAL库中延时的几种方式解析
HAL_Dalay()是毫秒级延时,为了使用微秒级延时最近学习了一下,总结如下,推荐使用最后一种方式。
/*
* 本文件包括四种延时方式:
* 1. 原来的HAL库函数HAL_Delay() 2. 采用定时器2设置延时函数 3. 采用系统滴答中断方式的ms和us级延时
* 4. 采用系统滴答非中断方式的ms和us级延时(在一次计数值范围内的延时)
*/
/* 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; //必须要加volatile!!!
volatile unsigned long time_delay; // 延时时间,注意定义为全局变量
/* 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); //注意这里HAL库重装了系统计数器的值,使美1ms中断一次!!
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)//定时器2中断处理函数
{
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)//自定义的定时器2实现延时的函数
{
timenum = num;
HAL_TIM_Base_Start_IT(&htim2);
while(timenum) //为什么一直停在这个循环中???3-2-1-2-3……怎么会这样!!!--volatile!
;
HAL_TIM_Base_Stop_IT(&htim2);
return HAL_OK;
}
//SysTick实现延时n_ms,中断方式
void delay_ms(volatile unsigned long nms)
{
//SYSTICK分频--1ms的系统时钟中断
if (SysTick_Config(HAL_RCC_GetHCLKFreq()/1000))
{
while (1);
}
time_delay=nms;//读取定时时间
while(time_delay);
SysTick->CTRL=0x00; //关闭计数器
SysTick->VAL =0X00; //清空计数器
}
//SysTick实现延时n_us,中断方式
void delay_us(volatile unsigned long nus)
{
//SYSTICK分频--1us的系统时钟中断
if (SysTick_Config(HAL_RCC_GetHCLKFreq()/1000000))
{
while (1);
}
time_delay=nus;//读取定时时间
while(time_delay);
SysTick->CTRL=0x00; //关闭计数器
SysTick->VAL =0X00; //清空计数器
}
//SysTick实现延时中断方式的中断处理函数
//在中断中将time_delay递减。实现延时
//void SysTick_Handler(void)
//{
// if(time_delay)
// time_delay--;
//}
//void HAL_SYSTICK_Callback(void)//原cube HAL库中中断处理回调函数重写
//{
// if(time_delay)
// time_delay--;
//}
//void HAL_IncTick(void)//原cube HAL库中,重写
//{
// if(time_delay)
// time_delay--;
//}
/********************************* 优选的方式 ***********************************************************************/
/*一次填充系统计时器以实现非中断延迟,受限系统计时器stmtick只有24位,所以最长计时有所限制*/
void delay_ms2(int32_t nms)
{
int32_t temp;
SysTick->LOAD = 8000*nms;
SysTick->VAL=0X00;//清空计数器
SysTick->CTRL=0X01;//使能,减到零是无动作,采用外部时钟源
do
{
temp=SysTick->CTRL;//读取当前倒计数值
}while((temp&0x01)&&(!(temp&(1<<16))));//等待时间到达
SysTick->CTRL=0x00; //关闭计数器
SysTick->VAL =0X00; //清空计数器
}
/* USER CODE END 4 */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
/*********************************************************************************************************************/
/*********************************************************************************************************************/
/*********************************************************************************************************************/
/*如果自写系统时钟中断处理函数,需要在stml1xx_it.c中注释掉一下函数*/
/**
* @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