STM32 TIM定时器

Kozakemi Lv4
  2023-09-20 21:57:45 2023-09-20 21:57:45 创建   2024-05-17 13:47:59 2024-05-17 13:47:59 更新    1.9k 字  8 分钟  

大量参考江协科技 视频，十分感谢给出的教程

计算公式

CK_CNT=CK_PSC/(PSC+1)
CK_CNT_OV=CK_CNT/(ARR+1)
CK_CNT_OV=CK_PSC/(PSC+1)/(ARR+1)
# CK_PSC：stm32频率 72Mhz
# PSC：TIM_Prescaler值 max:65535  预分频器
# ARR：TIM_Period值 max:65535     自动重装器
# CK_CNT:计数计数频率
# CK_CNT_OV：频率

假设，计时1s,那么可先想到ARR=72,PSC=1000000,但是这样会超出max,所以，可以选用ARR=7200,PSC=10000的方案，但是不是唯一的，只要计算出CK_CNT_OV=1且设置的值不会超出即可，高的计数频率便设置高的计数，低的计数频率就设置低的计数

相关函数介绍

void TIM_DeInit(TIM_TypeDef* TIMx);//恢复默认配置
void TIM_TimeBaseInit(TIM_TypeDef* TIMx, TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct);//时基单元初始化
void TIM_TimeBaseStructInit(TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct);//结构体变量赋值初值

void TIM_Cmd(TIM_TypeDef* TIMx, FunctionalState NewState);//计数器使能
void TIM_ITConfig(TIM_TypeDef* TIMx, uint16_t TIM_IT, FunctionalState NewState);//使能中断

void TIM_InternalClockConfig(TIM_TypeDef* TIMx);//使用内部时钟
void TIM_ITRxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_InputTriggerSource);//使用itx其他定时器时钟
void TIM_TIxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_TIxExternalCLKSource,
                                uint16_t TIM_ICPolarity, uint16_t ICFilter);//选择tix捕获通道时钟

void TIM_ETRClockMode1Config(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, uint16_t TIM_ExtTRGPolarity,
                             uint16_t ExtTRGFilter);//etr通过外部时钟模式1输入的时钟
void TIM_ETRClockMode2Config(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, 
                             uint16_t TIM_ExtTRGPolarity, uint16_t ExtTRGFilter);//etr通过外部时钟模式2输入的时钟
void TIM_ETRConfig(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, uint16_t TIM_ExtTRGPolarity,
                   uint16_t ExtTRGFilter);//配置etr引脚的预分频器、极性、滤波器等参数
void TIM_PrescalerConfig(TIM_TypeDef* TIMx, uint16_t Prescaler, uint16_t TIM_PSCReloadMode);//修改预分频值
void TIM_CounterModeConfig(TIM_TypeDef* TIMx, uint16_t TIM_CounterMode);//改变计数器的计数模式
void TIM_ARRPreloadConfig(TIM_TypeDef* TIMx, FunctionalState NewState);//知道自动重装器预装功能配置
void TIM_SetCounter(TIM_TypeDef* TIMx, uint16_t Counter);//向指定计数器写入值
TIM_SetAutoreload(TIM_TypeDef* TIMx, uint16_t Autoreload);//给自动重装器写一个值
uint16_t TIM_GetCounter(TIM_TypeDef* TIMx);//获取当前计数器的值
uint16_t TIM_GetPrescaler(TIM_TypeDef* TIMx);//获取当前预分频器的值
/*获取/清除标志位*/
FlagStatus TIM_GetFlagStatus(TIM_TypeDef* TIMx, uint16_t TIM_FLAG);
void TIM_ClearFlag(TIM_TypeDef* TIMx, uint16_t TIM_FLAG);
ITStatus TIM_GetITStatus(TIM_TypeDef* TIMx, uint16_t TIM_IT);
void TIM_ClearITPendingBit(TIM_TypeDef* TIMx, uint16_t TIM_IT);

配置使用内部时钟

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);//启用定时器2的时钟
	
	TIM_InternalClockConfig(TIM2);//设置时钟为内部时钟
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;//初始化定时器结构体
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;//设置分频系数
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//设置计数模式
	TIM_TimeBaseInitStructure.TIM_Period = 10000 - 1;//设置自动重装值
	TIM_TimeBaseInitStructure.TIM_Prescaler = 7200 - 1;//设置预分频器的值
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//设置重复寄存器值，仅高级寄存器有效
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);//初始化定时器
	
	TIM_ClearFlag(TIM2, TIM_FLAG_Update);//防止初始化时进入中断
	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);//启用定时器
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置NVIC智能高端分组
	
	NVIC_InitTypeDef NVIC_InitStructure;//初始化NVIC结构体
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;//设置中断触发通道
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//启用
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;//设置抢占优先级值
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;//设置响应优先级的值
	NVIC_Init(&NVIC_InitStructure);//初始化 NVIC
	
	TIM_Cmd(TIM2, ENABLE);//启用TIM2定时器
}

void TIM2_IRQHandler(void)//定时中断函数
{
	if (TIM_GetITStatus(TIM2, TIM_IT_Update) == SET)
	{
		
		TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
	}
}

假设使用TIM2

配置时钟

TIM2属于APB1总线的外设，所以初始化APB1

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

选择时基单元时钟

这里先择使用内部时钟，其实使用内部时钟也可以不写，默认就是使用内部时钟

TIM_InternalClockConfig(TIM2);

配置时基单元

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);

其中结构体

TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInitStructure.TIM_Period = 10000 - 1; //ARR
TIM_TimeBaseInitStructure.TIM_Prescaler = 7200 - 1; //PSC
TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;·

TIM_ClockDivision：指定时钟分频

/** @defgroup TIM_Clock_Division_CKD 
  * @{
  */

#define TIM_CKD_DIV1                       ((uint16_t)0x0000)//不分频
#define TIM_CKD_DIV2                       ((uint16_t)0x0100)//2分频
#define TIM_CKD_DIV4                       ((uint16_t)0x0200)//4分频
#define IS_TIM_CKD_DIV(DIV) (((DIV) == TIM_CKD_DIV1) || \
                             ((DIV) == TIM_CKD_DIV2) || \
                             ((DIV) == TIM_CKD_DIV4))

TIM_CounterMode：计数模式

/** @defgroup TIM_Counter_Mode 
  * @{
  */

#define TIM_CounterMode_Up                 ((uint16_t)0x0000)//向上计数
#define TIM_CounterMode_Down               ((uint16_t)0x0010)//向下计数
#define TIM_CounterMode_CenterAligned1     ((uint16_t)0x0020)//三种中央对齐
#define TIM_CounterMode_CenterAligned2     ((uint16_t)0x0040)
#define TIM_CounterMode_CenterAligned3     ((uint16_t)0x0060)
#define IS_TIM_COUNTER_MODE(MODE) (((MODE) == TIM_CounterMode_Up) ||  \
                                   ((MODE) == TIM_CounterMode_Down) || \
                                   ((MODE) == TIM_CounterMode_CenterAligned1) || \
                                   ((MODE) == TIM_CounterMode_CenterAligned2) || \
                                   ((MODE) == TIM_CounterMode_CenterAligned3))

TIM_Period：周期，ARR自动重装器的值

TIM_Prescaler：预分频器的值

上两式需要以下公式

CK_CNT_OV=CK_CNT/(ARR+1)=CK_PSC/(PSC+1)/(ARR+1)

假设定时1s，也就是1hz，1=75m/10000/7200，也就是PSC=10000-1，ARR=7200-1，需要注意的是这不是唯一解，但是需要注意的是值需要0~65535之间

TIM_RepetitionCounter：重复计数器的值，此为高级计数器才有，TIM2为普通计数器，没有此项

使能中断

TIM_ClearFlag(TIM2, TIM_FLAG_Update);
/**
  * @brief  Clears the TIMx's pending flags.
  * @param  TIMx: where x can be 1 to 17 to select the TIM peripheral.
  * @param  TIM_FLAG: specifies the flag bit to clear.
  *   This parameter can be any combination of the following values:
  *     @arg TIM_FLAG_Update: TIM update Flag
  *     @arg TIM_FLAG_CC1: TIM Capture Compare 1 Flag
  *     @arg TIM_FLAG_CC2: TIM Capture Compare 2 Flag
  *     @arg TIM_FLAG_CC3: TIM Capture Compare 3 Flag
  *     @arg TIM_FLAG_CC4: TIM Capture Compare 4 Flag
  *     @arg TIM_FLAG_COM: TIM Commutation Flag
  *     @arg TIM_FLAG_Trigger: TIM Trigger Flag
  *     @arg TIM_FLAG_Break: TIM Break Flag
  *     @arg TIM_FLAG_CC1OF: TIM Capture Compare 1 overcapture Flag
  *     @arg TIM_FLAG_CC2OF: TIM Capture Compare 2 overcapture Flag
  *     @arg TIM_FLAG_CC3OF: TIM Capture Compare 3 overcapture Flag
  *     @arg TIM_FLAG_CC4OF: TIM Capture Compare 4 overcapture Flag
  * @note
  *   - TIM6 and TIM7 can have only one update flag. 
  *   - TIM9, TIM12 and TIM15 can have only TIM_FLAG_Update, TIM_FLAG_CC1,
  *      TIM_FLAG_CC2 or TIM_FLAG_Trigger. 
  *   - TIM10, TIM11, TIM13, TIM14, TIM16 and TIM17 can have TIM_FLAG_Update or TIM_FLAG_CC1.   
  *   - TIM_FLAG_Break is used only with TIM1, TIM8 and TIM15. 
  *   - TIM_FLAG_COM is used only with TIM1, TIM8, TIM15, TIM16 and TIM17.   
  * @retval None
  */
void TIM_ClearFlag(TIM_TypeDef* TIMx, uint16_t TIM_FLAG)

参数1、选择定时器

参数2、更新中断

参数3、是否启用

配置NVIC

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置中断分组

NVIC_InitTypeDef NVIC_InitStructure;//创建结构体
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;//中断通道
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//启用
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;//抢占优先级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;//响应优先级
NVIC_Init(&NVIC_InitStructure);//启动

启用定时器

TIM_Cmd(TIM2, ENABLE);

书写中断函数

void TIM2_IRQHandler(void)
{
	if (TIM_GetITStatus(TIM2, TIM_IT_Update) == SET)//确认是否是TIM2中断
	{
        /*code*/
		TIM_ClearITPendingBit(TIM2, TIM_IT_Update);//清除中断标志位
	}
}

总结

第一步，配置RCC定时器的时钟

第二步，配置时基单元为内部时钟（可以忽略）

第三步，配置时基单元，这一步最为重要

第四步，开启中断

第五步，配置NVIC以配置中断通道与中断的优先级

第六步，启动定时器

第七步，中断函数的具体实现

添加使用外部时钟

假设将外部时钟在PA0口

使用外部时钟

将**TIM_InternalClockConfig(TIM2);**替换为

即配置为外部时钟

TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, 0x0F);
/**
  * @brief  Configures the External clock Mode2
  * @param  TIMx: where x can be  1, 2, 3, 4, 5 or 8 to select the TIM peripheral.
  * @param  TIM_ExtTRGPrescaler: The external Trigger Prescaler.
  *   This parameter can be one of the following values:
  *     @arg TIM_ExtTRGPSC_OFF: ETRP Prescaler OFF.
  *     @arg TIM_ExtTRGPSC_DIV2: ETRP frequency divided by 2.
  *     @arg TIM_ExtTRGPSC_DIV4: ETRP frequency divided by 4.
  *     @arg TIM_ExtTRGPSC_DIV8: ETRP frequency divided by 8.
  * @param  TIM_ExtTRGPolarity: The external Trigger Polarity.
  *   This parameter can be one of the following values:
  *     @arg TIM_ExtTRGPolarity_Inverted: active low or falling edge active.
  *     @arg TIM_ExtTRGPolarity_NonInverted: active high or rising edge active.
  * @param  ExtTRGFilter: External Trigger Filter.
  *   This parameter must be a value between 0x00 and 0x0F
  * @retval None
  */
void TIM_ETRClockMode2Config(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, 
                             uint16_t TIM_ExtTRGPolarity, uint16_t ExtTRGFilter)

参数1、配置时钟TIMx

参数2、分频值

参数3、外部触发的极性，TIM_ExtTRGPolarity_Inverted下降沿或低电平有效，TIM_ExtTRGPolarity_NonInverted上升沿或者高电平有效

参数4、外部触发滤波器0x00 ~ 0x0f之间的值以采样频率f采样N个点

image-20230920215124322

初始化时钟与GPIO

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//当小电平时，推荐使用浮空输入，如果电平够大，可以使用上拉输入，好处是防止跳动
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

改动后代码

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, 0xff);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStructure.TIM_Period = 10 - 1;
	TIM_TimeBaseInitStructure.TIM_Prescaler = 1 - 1;
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);
	
	TIM_ClearFlag(TIM2, TIM_FLAG_Update);
	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	
	TIM_Cmd(TIM2, ENABLE);
}

总结

第一步，配置RCC定时器的时钟，相较于内部时钟需要额外配置GPIO的时钟

第二步，配置时基单元为外部时钟，设置时钟号、分频值、触发极性、滤波器

之后的操作与配置使用内部时钟无异

  • 标题: STM32 TIM定时器
  • 作者: Kozakemi
  • 创建于 : 2023-09-20 21:57:45
  • 更新于 : 2024-05-17 13:47:59
  • 链接: https://kozakemi.gitlab.io/post/12e3998c.html
  • 版权声明: 本文章采用 CC BY-NC-SA 4.0 进行许可。
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此页目录
STM32 TIM定时器
  1. 计算公式
  2. 相关函数介绍
  3. 配置使用内部时钟
    1. 配置时钟
    2. 选择时基单元时钟
    3. 配置时基单元
    4. 使能中断
    5. 配置NVIC
    6. 启用定时器
    7. 书写中断函数
    8. 总结
  4. 添加使用外部时钟
    1. 使用外部时钟
    2. 初始化时钟与GPIO
    3. 改动后代码
    4. 总结