stm32f103对定时器2通道34输出的pwn波并记高电平次数标准库代码
时间: 2024-06-12 17:06:22 浏览: 3
以下是基于STM32F103标准库的代码示例,用于将定时器2的通道3和4配置为PWM输出,并计算高电平的次数:
```c
#include "stm32f10x.h"
#define PWM_PERIOD 999 // PWM周期为1ms
volatile uint32_t high_count = 0; // 记录高电平次数的计数器
void TIM2_IRQHandler(void)
{
if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET) // 检查通道3的中断标志位
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC3); // 清除中断标志位
if (GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_2)) // 检查PA2引脚的电平
{
high_count++; // 如果是高电平,增加计数器
}
}
else if (TIM_GetITStatus(TIM2, TIM_IT_CC4) != RESET) // 检查通道4的中断标志位
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC4); // 清除中断标志位
}
}
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
// 使能GPIOA和TIM2的时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
// 配置PA2引脚为GPIO输入
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOA, &GPIO_InitStructure);
// 配置TIM2的时间基准
TIM_TimeBaseStructure.TIM_Period = PWM_PERIOD;
TIM_TimeBaseStructure.TIM_Prescaler = 71; // 时钟预分频器的值为72-1
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
// 配置TIM2的通道3为PWM输出
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 500; // 占空比为50%
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC3Init(TIM2, &TIM_OCInitStructure);
// 配置TIM2的通道4为PWM输出
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 250; // 占空比为25%
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC4Init(TIM2, &TIM_OCInitStructure);
// 使能TIM2的通道3和4中断
TIM_ITConfig(TIM2, TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
// 配置TIM2的中断优先级
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// 启动定时器2
TIM_Cmd(TIM2, ENABLE);
while (1)
{
// 实现其他代码逻辑
}
}
```
在此示例中,我们将定时器2的时间基准设置为1ms,然后将通道3和4配置为PWM输出,分别设置占空比为50%和25%。我们还使用了PA2引脚作为输入,以检测高电平的次数。在TIM2_IRQHandler()函数中,我们检查通道3和4的中断标志位,并在检测通道3中断时增加计数器。最后,在主循环中可以通过读取high_count变量来获取高电平的次数。