void EXTI_ClearITPendingBit(uint32_t EXTI_Line)void EXTI_ClearFlag(uint32_t EXTI_Line)
时间: 2024-04-25 08:21:40 浏览: 12
这两个函数是用于清除外部中断标志位的函数。
`EXTI_ClearITPendingBit`函数用于清除指定的外部中断线的中断挂起位,参数`EXTI_Line`表示需要清除的外部中断线。该函数将会清除指定外部中断线上的中断挂起位,以便下一次触发中断时能够正确地检测到中断事件。
`EXTI_ClearFlag`函数用于清除指定的外部中断线的中断标志位,参数`EXTI_Line`表示需要清除的外部中断线。该函数将会清除指定外部中断线上的中断标志位,以便下一次触发中断时能够正确地检测到中断事件。
这两个函数通常在外部中断的中断处理函数中使用,用于在处理完中断后清除相应的标志位,以确保下一次触发中断时能够正常工作。
相关问题
stm32中使用pulsesensor传感器检测心率使用c语言,程序该怎么写
使用PulseSensor检测心率需要使用STM32的定时器和外部中断。以下是一份示例代码,可以供参考:
```c
#include "stm32f10x.h"
#define PULSE_SENSOR_PIN GPIO_Pin_0
#define PULSE_SENSOR_PORT GPIOA
#define PULSE_SENSOR_EXTI_LINE EXTI_Line0
#define PULSE_TIMER TIM2
volatile uint16_t pulse_count = 0; // 脉冲计数器
volatile uint16_t last_bpm = 0; // 上一次计算得到的心率值
void init_gpio(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); // 使能GPIOA时钟
GPIO_InitStructure.GPIO_Pin = PULSE_SENSOR_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(PULSE_SENSOR_PORT, &GPIO_InitStructure);
}
void init_timer(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); // 使能TIM2时钟
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_Prescaler = 71; // 分频器,使定时器频率为1MHz
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(PULSE_TIMER, &TIM_TimeBaseStructure);
TIM_ClearFlag(PULSE_TIMER, TIM_FLAG_Update); // 清除更新标志位
TIM_ITConfig(PULSE_TIMER, TIM_IT_Update, ENABLE); // 使能更新中断
}
void init_exti(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0); // 关联GPIOA.0和外部中断线0
EXTI_InitStructure.EXTI_Line = PULSE_SENSOR_EXTI_LINE;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling; // 上升沿和下降沿都触发中断
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void EXTI0_IRQHandler(void)
{
if (EXTI_GetITStatus(PULSE_SENSOR_EXTI_LINE) != RESET) {
pulse_count++; // 脉冲计数器加1
EXTI_ClearITPendingBit(PULSE_SENSOR_EXTI_LINE); // 清除中断标志位
}
}
void TIM2_IRQHandler(void)
{
if (TIM_GetITStatus(PULSE_TIMER, TIM_IT_Update) != RESET) {
uint16_t bpm;
TIM_ClearITPendingBit(PULSE_TIMER, TIM_FLAG_Update); // 清除更新标志位
bpm = pulse_count * 60 / 2; // 计算心率值
last_bpm = bpm;
pulse_count = 0; // 清零脉冲计数器
}
}
int main(void)
{
init_gpio();
init_timer();
init_exti();
TIM_Cmd(PULSE_TIMER, ENABLE); // 启动定时器
while (1) {
// 这里可以进行其他的操作
}
}
```
在这个例子中,我们使用PA0作为PulseSensor的输入引脚,并将其连接到外部中断线0。使用TIM2作为定时器,计算脉冲的数量,并在定时器中断处理程序中计算心率值。注意,定时器的频率应该足够高,以便精确计算心率值。
STM32F103C8T6单片机NEC红外信号解码程序
好的,这个问题我可以帮你回答。下面是一个简单的STM32F103C8T6单片机NEC红外信号解码程序的示例代码:
```c
#include "stm32f10x.h"
#define IR_PORT GPIOA
#define IR_PIN GPIO_Pin_0
volatile uint16_t ir_code = 0;
volatile uint8_t ir_state = 0;
void EXTI0_IRQHandler(void) {
if (EXTI_GetITStatus(EXTI_Line0) != RESET) {
EXTI_ClearITPendingBit(EXTI_Line0);
if (ir_state == 0) {
TIM2->CNT = 0;
TIM_Cmd(TIM2, ENABLE);
ir_state = 1;
} else if (ir_state == 1) {
ir_code = TIM2->CNT;
TIM_Cmd(TIM2, DISABLE);
ir_state = 2;
}
}
}
void TIM2_IRQHandler(void) {
if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) {
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
ir_state = 0;
}
}
int main(void) {
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
GPIO_InitStructure.GPIO_Pin = IR_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(IR_PORT, &GPIO_InitStructure);
EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ClearFlag(TIM2, TIM_FLAG_Update);
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
while (1) {
if (ir_code != 0) {
// decode NEC infrared signal
// ...
ir_code = 0;
}
}
}
```
这个示例程序使用了外部中断和定时器来解码NEC红外信号。当红外接收器接收到一个NEC红外信号的起始脉冲时,会触发外部中断。在中断处理函数中,根据当前状态分别启动和停止定时器,以计算红外信号的脉宽。当定时器溢出时,会触发另一个中断处理函数,重置状态。在主循环中,如果检测到一个完整的红外信号,则进行解码处理。