1.使能对应USART模块时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USARTx, ENABLE) for USART1 and USART6
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USARTx, ENABLE) for USART2, USART3, UART4 or UART5.
2.使能对应GPIO的时钟
RCC_AHB1PeriphClockCmd() function. (The I/O can be TX, RX, CTS, or/and SCLK).
3.配置对应引脚的复用功能
GPIO_PinAFConfig(GPIOx, GPIO_PinSourcex, GPIO_AF_USARTx); //引脚映射
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; // 设置为推挽输出
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用模式
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_x | GPIO_Pin_x; //引脚选择
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_xxMHz; //速度选择
GPIO_Init(GPIOx, &GPIO_InitStructure); //写入配置信息
4.配置USART信息
USART_https://www.doczj.com/doc/b218293237.html,ART_BaudRate = xxx; //波特率
USART_https://www.doczj.com/doc/b218293237.html,ART_WordLength = USART_WordLength_xb;//字长
USART_https://www.doczj.com/doc/b218293237.html,ART_StopBits = USART_StopBits_x; //停止位
USART_https://www.doczj.com/doc/b218293237.html,ART_Parity = USART_Parity_No; //校验位,USART_Parity_Even,USART_Parity_Odd
USART_https://www.doczj.com/doc/b218293237.html,ART_HardwareFlowControl = USART_HardwareFlowControl_None;//硬件流控
USART_https://www.doczj.com/doc/b218293237.html,ART_Mode = USART_Mode_Rx | USART_Mode_Tx; //工作模式
USART_Init(USARTx, &USART_InitStructure); //写入配置信息
USART_Cmd(USARTx, ENABLE); //使能串口模块
5.发送
USART_SendData(USARTx, char xx); //发送字符
while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);//等待发送完成
6.接收
if(USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == SET) //查询是否接收到数据xxx=USART_ReceiveData(USARTx) //读
取接收到的数据
程序举例：
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_USART1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_USART1);
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
USART_https://www.doczj.com/doc/b218293237.html,ART_BaudRate = 115200;
USART_https://www.doczj.com/doc/b218293237.html,ART_WordLength = USART_WordLength_8b;
USART_https://www.doczj.com/doc/b218293237.html,ART_StopBits = USART_StopBits_1;
USART_https://www.doczj.com/doc/b218293237.html,ART_Parity = USART_Parity_No;
USART_https://www.doczj.com/doc/b218293237.html,ART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_https://www.doczj.com/doc/b218293237.html,ART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
USART_Cmd(USART1, ENABLE);
while (1)
{
if(USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == SET)
{
USART_SendData(USART1, USART_ReceiveData(USART1));
while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
}
}
}