利用stm32f103c8t6实现蓝牙音乐播放的代码

首先，需要连接一个蓝牙模块到STM32F103C8T6。这个可以通过UART接口来完成。然后，需要使用某个音频芯片来输出音频信号。最简单的方法是使用PWM输出音频信号，但是音质可能不够好。如果要获得更好的音质，可以考虑使用带DAC的音频芯片。

接下来是蓝牙音乐播放的代码：

#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_usart.h"
#include "stm32f10x_dma.h"

#define USART_RX_BUFFER_SIZE 1024
char usart_rx_buffer[USART_RX_BUFFER_SIZE];
volatile uint16_t usart_rx_head = 0;
volatile uint16_t usart_rx_tail = 0;

void USART1_IRQHandler(void)
{
    if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
    {
        usart_rx_buffer[usart_rx_head] = USART_ReceiveData(USART1);
        usart_rx_head = (usart_rx_head + 1) % USART_RX_BUFFER_SIZE;
    }
}

void bluetooth_init(void)
{
    USART_InitTypeDef usart_init;
    DMA_InitTypeDef dma_init;
    NVIC_InitTypeDef nvic_init;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

    USART_DeInit(USART1);

    usart_init.USART_BaudRate = 9600;
    usart_init.USART_WordLength = USART_WordLength_8b;
    usart_init.USART_StopBits = USART_StopBits_1;
    usart_init.USART_Parity = USART_Parity_No;
    usart_init.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    usart_init.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USART1, &usart_init);

    nvic_init.NVIC_IRQChannel = USART1_IRQn;
    nvic_init.NVIC_IRQChannelPreemptionPriority = 0;
    nvic_init.NVIC_IRQChannelSubPriority = 0;
    nvic_init.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&nvic_init);

    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

    USART_Cmd(USART1, ENABLE);

    DMA_DeInit(DMA1_Channel4);
    dma_init.DMA_PeripheralBaseAddr = (uint32_t)&USART1->DR;
    dma_init.DMA_MemoryBaseAddr = (uint32_t)usart_rx_buffer;
    dma_init.DMA_DIR = DMA_DIR_PeripheralSRC;
    dma_init.DMA_BufferSize = USART_RX_BUFFER_SIZE;
    dma_init.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    dma_init.DMA_MemoryInc = DMA_MemoryInc_Enable;
    dma_init.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    dma_init.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    dma_init.DMA_Mode = DMA_Mode_Circular;
    dma_init.DMA_Priority = DMA_Priority_VeryHigh;
    dma_init.DMA_M2M = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel4, &dma_init);

    DMA_Cmd(DMA1_Channel4, ENABLE);
}

void dac_init(void)
{
    GPIO_InitTypeDef gpio_init;
    DAC_InitTypeDef dac_init;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);

    GPIO_StructInit(&gpio_init);
    gpio_init.GPIO_Pin = GPIO_Pin_4;
    gpio_init.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_Init(GPIOA, &gpio_init);

    DAC_StructInit(&dac_init);
    dac_init.DAC_Trigger = DAC_Trigger_None;
    dac_init.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
    DAC_Init(DAC_Channel_1, &dac_init);

    DAC_Cmd(DAC_Channel_1, ENABLE);
}

void play_music(uint8_t *data, uint16_t size)
{
    uint16_t i;

    for (i = 0; i < size; i++)
    {
        DAC_SetChannel1Data(DAC_Align_8b_R, data[i]);
        while (DAC_GetFlagStatus(DAC_FLAG_DMAUDR) == RESET);
    }
}

int main(void)
{
    uint8_t buffer[1024];
    uint16_t buffer_size;

    SystemInit();

    bluetooth_init();
    dac_init();

    while (1)
    {
        if (usart_rx_head != usart_rx_tail)
        {
            buffer_size = (usart_rx_head - usart_rx_tail + USART_RX_BUFFER_SIZE) % USART_RX_BUFFER_SIZE;
            if (buffer_size > sizeof(buffer)) buffer_size = sizeof(buffer);
            memcpy(buffer, &usart_rx_buffer[usart_rx_tail], buffer_size);
            usart_rx_tail = (usart_rx_tail + buffer_size) % USART_RX_BUFFER_SIZE;

            play_music(buffer, buffer_size);
        }
    }
}

这个代码实现了一个简单的蓝牙音乐播放器。它从蓝牙模块接收数据，然后使用DAC输出音频信号。当数据量较大时，可能会有一些延迟，但是对于简单的应用场景来说，这个代码已经足够了。