stm32实现蜂鸣器唱两只老虎

好的，我可以帮你解答这个问题。要实现这个功能，需要用到STM32的定时器和PWM模块。

首先，需要将蜂鸣器连接到STM32的一个GPIO口上。然后，需要配置一个定时器，让其以一定的频率产生一个PWM信号。PWM信号的占空比可以控制蜂鸣器的声音大小和音调高低。

接下来，需要编写一段程序，在定时器中断中不断改变PWM信号的占空比，以产生两只老虎的音调。具体的实现方法可以参考如下代码：

#include "stm32f10x.h"

#define BEEP_GPIO_PIN   GPIO_Pin_8
#define BEEP_GPIO_PORT  GPIOB

#define TIMER_PRESCALER 71
#define TIMER_PERIOD    999

#define NOTE_C          (uint16_t)(TIMER_PERIOD * 261.63 / 1000000)
#define NOTE_D          (uint16_t)(TIMER_PERIOD * 293.66 / 1000000)
#define NOTE_E          (uint16_t)(TIMER_PERIOD * 329.63 / 1000000)
#define NOTE_F          (uint16_t)(TIMER_PERIOD * 349.23 / 1000000)
#define NOTE_G          (uint16_t)(TIMER_PERIOD * 392.00 / 1000000)
#define NOTE_A          (uint16_t)(TIMER_PERIOD * 440.00 / 1000000)
#define NOTE_B          (uint16_t)(TIMER_PERIOD * 493.88 / 1000000)

uint16_t melody[] = {NOTE_C, NOTE_C, NOTE_D, NOTE_D, NOTE_E, NOTE_E, NOTE_D, NOTE_C, NOTE_B, NOTE_B, NOTE_A, NOTE_A, NOTE_G, NOTE_G, NOTE_F, NOTE_F};
uint8_t noteDurations[] = {4, 4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 4, 4, 2, 4, 4};

volatile uint8_t noteIndex = 0;
volatile uint8_t noteDuration = 0;

void TIM2_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

        if (noteDuration == 0)
        {
            noteDuration = noteDurations[noteIndex];
            noteIndex = (noteIndex + 1) % sizeof(noteDurations);
        }

        if (noteDuration > 0)
        {
            GPIO_WriteBit(BEEP_GPIO_PORT, BEEP_GPIO_PIN, Bit_SET);
            TIM_SetCompare2(TIM2, melody[noteIndex]);
        }
        else
        {
            GPIO_WriteBit(BEEP_GPIO_PORT, BEEP_GPIO_PIN, Bit_RESET);
            TIM_SetCompare2(TIM2, 0);
        }

        noteDuration--;
    }
}

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    GPIO_InitStructure.GPIO_Pin = BEEP_GPIO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(BEEP_GPIO_PORT, &GPIO_InitStructure);

    TIM_TimeBaseStructure.TIM_Period = TIMER_PERIOD;
    TIM_TimeBaseStructure.TIM_Prescaler = TIMER_PRESCALER;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC2Init(TIM2, &TIM_OCInitStructure);

    TIM_SetCompare2(TIM2, 0);

    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
    TIM_Cmd(TIM2, ENABLE);

    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);

    while (1)
    {
    }
}

这段代码实现了通过TIM2定时器产生PWM信号控制蜂鸣器发出两只老虎的音调。其中，`melody`数组和`noteDurations`数组分别表示两只老虎的音符和持续时间。在定时器中断中，通过改变PWM信号的占空比来产生不同的音高和音长。在`main`函数中，首先配置了GPIO口和定时器，然后启用定时器中断，进入循环等待中断事件的发生。

希望这个回答能够帮助到你！