stm32f107rc利用使蜂鸣器响的代码

您可以通过以下代码在STM32F107RC上使用定时器来控制蜂鸣器：

#include "stm32f10x.h"

#define BEEP_GPIO GPIOB
#define BEEP_PIN GPIO_Pin_8

void BEEP_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    
    GPIO_InitStructure.GPIO_Pin = BEEP_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(BEEP_GPIO, &GPIO_InitStructure);
    
    GPIO_ResetBits(BEEP_GPIO, BEEP_PIN);
}

void BEEP_Sound(uint32_t freq, uint32_t duration)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    uint16_t prescalerValue = 0;
    
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    
    // 配置TIM2为PWM模式
    TIM_TimeBaseStructure.TIM_Period = 20000;
    TIM_TimeBaseStructure.TIM_Prescaler = prescalerValue;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    
    // 配置TIM2通道1为PWM输出
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = (20000 / (2 * freq));
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);
    
    TIM_Cmd(TIM2, ENABLE);
    
    // 延时一段时间
    delay_ms(duration);
    
    TIM_OC1PreloadConfig(TIM2, DISABLE);
    TIM_Cmd(TIM2, DISABLE);
    TIM_ITConfig(TIM2, TIM_IT_CC1, DISABLE);
    
    GPIO_ResetBits(BEEP_GPIO, BEEP_PIN);
}

int main(void)
{
    BEEP_Init();
    
    while (1)
    {
        BEEP_Sound(1000, 1000);
        delay_ms(2000);
    }
}

这个代码使用了TIM2定时器的PWM模式来控制蜂鸣器。在`BEEP_Sound`函数中，我们首先配置了TIM2的定时器和通道1的PWM输出，然后通过`TIM_OC1Init`函数来控制频率，最后通过`delay_ms`函数来控制响铃的持续时间。