STM32F103C8T6串口2USART2程序

以下是 STM32F103C8T6串口2USART2程序的代码：

#include "stm32f10x.h"

void USART2_Init(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    USART_InitTypeDef USART_InitStructure;
    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx;
    USART_Init(USART2, &USART_InitStructure);

    USART_Cmd(USART2, ENABLE);
}

void USART2_SendChar(char ch)
{
    while (USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
    USART_SendData(USART2, ch);
}

void USART2_SendString(char* str)
{
    while (*str)
    {
        USART2_SendChar(*str++);
    }
}

int main(void)
{
    USART2_Init();
    USART2_SendString("Hello World!");

    while (1);

    return 0;
}

以上代码实现了 STM32F103C8T6 的串口2（USART2）初始化和发送字符串功能。其中，`USART2_Init()` 函数用于初始化串口，`USART2_SendChar()` 函数用于发送单个字符，`USART2_SendString()` 函数用于发送字符串。