stm32f407用keil5实现测量输入频率的完整代码
时间: 2023-10-10 11:12:40 浏览: 41
以下是一个简单的代码示例,使用STM32F407的TIM2通道来测量输入频率:
```c
#include "stm32f4xx.h"
#define PRESCALER_VALUE 1000 // 定时器预分频系数
#define PERIOD_VALUE 1000 // 定时器计数周期
volatile uint32_t freq = 0; // 存储测量到的频率值
void TIM2_IRQHandler(void) {
if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) {
freq = TIM_GetCapture1(TIM2);
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
}
}
int main(void) {
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_TIM2);
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TimeBaseStructure.TIM_Period = PERIOD_VALUE - 1;
TIM_TimeBaseStructure.TIM_Prescaler = PRESCALER_VALUE - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ICInitTypeDef TIM_ICInitStructure;
TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0;
TIM_ICInit(TIM2, &TIM_ICInitStructure);
TIM_Cmd(TIM2, ENABLE);
NVIC_InitTypeDef NVIC_InitStructure;
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);
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
TIM_ITConfig(TIM2, TIM_IT_CC1, ENABLE);
while (1) {
// 在这里可以使用freq变量来执行其他操作
}
}
```
此代码使用TIM2通道1捕获输入信号,并使用TIM2的更新中断来获取捕获的频率计数值。注意,此代码假定输入信号连接到了PA0引脚。
在main函数的无限循环中,可以使用freq变量来执行其他操作,例如将其发送到串口或显示在LCD屏幕上。