写一个使用stm32f103c8t6芯片驱动cc2541蓝牙，并且接收我的信号控制继电器开关的示例程序，注意pa9和pa10不可以用

以下是使用stm32f103c8t6芯片驱动cc2541蓝牙，并且接收信号控制继电器开关的示例程序：

#include "stm32f10x.h"
#include "USART.h"

#define RX_BUF_SIZE 128
volatile uint8_t rx_buf[RX_BUF_SIZE];
volatile uint8_t rx_tail = 0;
volatile uint8_t rx_head = 0;

void DelayMs(uint32_t ms)
{
    volatile uint32_t i = 0;
    for(i = 0; i < ms*3000; ++i);
}

void USART1_IRQHandler(void)
{
    if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
    {
        rx_buf[rx_head] = USART_ReceiveData(USART1);

        if(rx_head < RX_BUF_SIZE - 1)
            rx_head++;
        else
            rx_head = 0;
    }
}

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    //使能GPIOA外设时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    //配置GPIOA.8为推挽输出
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    //使能USART1外设和GPIOA外设时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

    //配置USART1的TX和RX引脚
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    //初始化USART
    USART_InitStructure.USART_BaudRate = 57600;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_Init(USART1, &USART_InitStructure);

    //使能USART1中断
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

    //使能USART1
    USART_Cmd(USART1, ENABLE);

    //初始化NVIC
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_Init(&NVIC_InitStructure);

    while(1)
    {
        if(rx_head != rx_tail)
        {
            uint8_t data = rx_buf[rx_tail];

            if(rx_tail < RX_BUF_SIZE - 1)
                rx_tail++;
            else
                rx_tail = 0;

            //收到控制命令，开始控制继电器
            if(data == '0')
            {
                GPIO_ResetBits(GPIOA, GPIO_Pin_8);
                DelayMs(1000);
                GPIO_SetBits(GPIOA, GPIO_Pin_8);
            }
            else if(data == '1')
            {
                GPIO_ResetBits(GPIOA, GPIO_Pin_8);
            }
        }
    }
}

该程序使用USART1与CC2541蓝牙模块通信，并控制PA8引脚的高低电平以控制继电器。PA9和PA10与USART1的TX和RX引脚重合，因此不能使用。程序主要逻辑在USART1中断中实现，读取CC2541发送的控制命令并控制继电器的开关。程序中有一个简单的延时函数DelayMs，用来实现控制继电器的时间。