STM32的共振频率扫描代码
时间: 2023-10-17 11:05:45 浏览: 34
在STM32中,可以通过使用定时器和捕获比较寄存器(TIM)来实现频率扫描。具体的代码实现如下:
```c
#include "stm32f10x.h"
// 定义定时器和捕获比较寄存器
#define TIMx TIM2
#define TIMx_IRQn TIM2_IRQn
#define TIMx_IRQHandler TIM2_IRQHandler
#define TIMx_IRQn_BIT (1<<28)
// 定义PWM输出的引脚
#define PWM_GPIO_PORT GPIOA
#define PWM_GPIO_PIN GPIO_Pin_0
#define PWM_GPIO_CLK RCC_APB2Periph_GPIOA
// 定义频率扫描的参数
#define FREQ_START 1000
#define FREQ_END 10000
#define FREQ_STEP 1000
// 定义状态变量
volatile uint16_t freq = FREQ_START;
volatile uint8_t dir = 1;
// 定义定时器中断服务函数
void TIMx_IRQHandler(void)
{
if (TIM_GetITStatus(TIMx, TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIMx, TIM_IT_CC1);
freq += FREQ_STEP * dir;
if (freq >= FREQ_END)
{
dir = -1;
freq = FREQ_END - FREQ_STEP;
}
else if (freq <= FREQ_START)
{
dir = 1;
freq = FREQ_START + FREQ_STEP;
}
TIM_SetAutoreload(TIMx, SystemCoreClock / freq);
}
}
int main(void)
{
// 初始化定时器和GPIO
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
RCC_APB2PeriphClockCmd(PWM_GPIO_CLK, ENABLE);
GPIO_InitStruct.GPIO_Pin = PWM_GPIO_PIN;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(PWM_GPIO_PORT, &GPIO_InitStruct);
TIM_TimeBaseInitStruct.TIM_Period = 0xFFFF;
TIM_TimeBaseInitStruct.TIM_Prescaler = 0;
TIM_TimeBaseInitStruct.TIM_ClockDivision = 0;
TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIMx, &TIM_TimeBaseInitStruct);
TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStruct.TIM_Pulse = 0;
TIM_OC1Init(TIMx, &TIM_OCInitStruct);
TIM_Cmd(TIMx, ENABLE);
TIM_ITConfig(TIMx, TIM_IT_CC1, ENABLE);
NVIC_InitTypeDef NVIC_InitStruct;
NVIC_InitStruct.NVIC_IRQChannel = TIMx_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);
// 开始频率扫描
while (1)
{
// do something
}
}
```
以上代码中,使用了定时器2(TIM2)作为PWM输出的定时器,并使用了定时器的捕获比较模式来实现频率扫描。在定时器中断服务函数(TIMx_IRQHandler)中,每当捕获比较事件发生时,就会改变PWM输出的频率,并将定时器的自动重装载值设置为SystemCoreClock / freq。在主函数中,可以执行其他操作,比如读取频率扫描结果等。