stm32f103c8t6驱动蜂鸣器唱歌

基于STM32F103C8T6的光敏电阻控制蜂鸣器报警系统可以通过控制蜂鸣器的PWM信号来实现唱歌功能。下面是一个简单的示例代码：

#include "stm32f10x.h"

void delay_ms(uint32_t ms) {
    for (uint32_t i = 0; i < ms; i++) {
        for (uint32_t j = 0; j < 2000; j++) {
            __NOP();
        }
    }
}

void PWM_Init(void) {
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_OCInitTypeDef TIM_OCInitStructure;
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 500;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);

    TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);
    TIM_ARRPreloadConfig(TIM2, ENABLE);

    TIM_Cmd(TIM2, ENABLE);
}

int main(void) {
    PWM_Init();

    while (1) {
        TIM2->CCR1 = 500; // 设置PWM占空比为50%
        delay_ms(500);
        TIM2->CCR1 = 0; // 关闭蜂鸣器
        delay_ms(500);
    }
}

这段代码使用了STM32的定时器2和GPIOA的引脚0来控制蜂鸣器。通过调整`TIM2->CCR1`的值来改变PWM的占空比，从而控制蜂鸣器的声音。在示例代码中，蜂鸣器会每隔500毫秒发出一次声音，持续时间为500毫秒。

请注意，以上代码只是一个简单的示例，实际应用中可能需要根据具体的需求进行修改和优化。