stm32f407用Keil5实现测量输入频率完整代码
时间: 2023-10-10 07:11:57 浏览: 66
以下是基于STM32F407芯片,使用Keil5编译器实现测量输入频率的完整代码:
```
#include "stm32f4xx.h"
#include "stdio.h"
#define BUFFER_SIZE 100
volatile uint32_t overflow_counter = 0;
volatile uint32_t frequency = 0;
volatile uint32_t buffer_index = 0;
volatile uint32_t buffer[BUFFER_SIZE] = {0};
void TIM2_IRQHandler(void) {
if (TIM2->SR & TIM_SR_UIF) {
TIM2->SR &= ~TIM_SR_UIF; // Clear update interrupt flag
overflow_counter++;
}
}
void EXTI0_IRQHandler(void) {
if (EXTI->PR & EXTI_PR_PR0) {
EXTI->PR |= EXTI_PR_PR0; // Clear pending bit
if (GPIOA->IDR & GPIO_IDR_ID0) {
// Rising edge detected
TIM2->CNT = 0; // Reset counter
overflow_counter = 0; // Reset overflow counter
TIM2->CR1 |= TIM_CR1_CEN; // Start timer
} else {
// Falling edge detected
TIM2->CR1 &= ~TIM_CR1_CEN; // Stop timer
frequency = (TIM2->CNT + overflow_counter * 65535) * 2; // Calculate frequency
overflow_counter = 0; // Reset overflow counter
buffer[buffer_index++] = frequency; // Store frequency in buffer
if (buffer_index >= BUFFER_SIZE) {
buffer_index = 0; // Reset buffer index
}
}
}
}
int main(void) {
// Enable GPIOA and TIM2 clocks
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
// Configure PA0 as input with pull-down
GPIOA->MODER &= ~GPIO_MODER_MODE0_Msk;
GPIOA->PUPDR |= GPIO_PUPDR_PUPD0_1;
// Configure TIM2 for input capture
TIM2->PSC = 83; // Prescaler = 84
TIM2->ARR = 65535; // Auto-reload value
TIM2->CCMR1 |= TIM_CCMR1_CC1S_0; // CC1 channel is configured as input, IC1 is mapped on TI1
TIM2->CCER |= TIM_CCER_CC1P; // Capture is done on falling edge
TIM2->DIER |= TIM_DIER_UIE; // Enable update interrupt
NVIC_EnableIRQ(TIM2_IRQn);
// Configure EXTI0 for interrupt on both edges
EXTI->IMR |= EXTI_IMR_MR0; // Interrupt request from line 0 is not masked
EXTI->RTSR |= EXTI_RTSR_TR0; // Rising edge trigger enabled
EXTI->FTSR |= EXTI_FTSR_TR0; // Falling edge trigger enabled
NVIC_EnableIRQ(EXTI0_IRQn);
// Enable interrupts
__enable_irq();
while (1) {
// Do something with the frequency buffer
}
}
```
代码的实现过程如下:
1. 首先,需要启用GPIOA和TIM2的时钟。
2. 配置PA0为输入模式,并启用下拉电阻。
3. 配置TIM2为输入捕获模式,使用CC1通道作为输入,捕获下降沿。同时,配置TIM2的预分频器和自动重载值。
4. 配置EXTI0为中断模式,并启用上升沿和下降沿触发。在中断处理程序中,检测到上升沿时启动TIM2计数器,并在检测到下降沿时停止计数器,并计算输入频率。将频率存储在缓冲区中。
5. 启用TIM2的更新中断,并在中断处理程序中处理溢出计数器。
6. 启用中断并进入主循环。在主循环中,可以使用缓冲区中的频率数据进行处理。
注意:以上代码仅提供参考,具体实现过程可能因硬件配置、应用场景等因素而有所不同。