串口的设置
串口的时序和工作原理就不写了,主要写如何应用
串口的设置除了GPIO外,需要设置的参数有波特率、数据位、停止位,校验方式;
GPIO输出配置AF_PP复用推挽输出
GPIO出入配置IN_FLAOTING浮空输入
USART的配置为115200的波特率,8位数据长度,1位停止位,无校验,无硬件流控制
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
/* config USART1 clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);//打开GPIO和USART1时钟
/* USART1 GPIO config */
/* Configure USART1 Tx (PA.09) as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Configure USART1 Rx (PA.10) as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* USART1 mode config */
USART_InitStructure.USART_BaudRate = 115200;
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_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
/*使能串口1的接收中断 */
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
//使能串口1
USART_Cmd(USART1, ENABLE);
配置接收中断的中断等级
NVIC_InitTypeDef NVIC_InitStructure;
/* Configure the NVIC Preemption Priority Bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
/* Enable the USARTy Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
接收中断函数的实现
void USART1_IRQHandler(void)
{
uint8_t ch;
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
{
//ch = USART1-》DR;
ch = USART_ReceiveData(USART1);
printf( “%c”, ch ); //将受到的内容发送出去
}
}
发送数据的实现
/* 发送一个字节到串口 */
USART_SendData(USART1, (uint8_t) ch);
/*等待发送完成*/
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
实现调试的printf,scanf函数
实现printf和scanf函数必须要重写,并包含#include 《stdio.h》
/// 重定向c库中printf到USART1
int fputc(int ch, FILE *f)
{
USART_SendData(USART1, (uint8_t) ch);
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
return (ch);
}
/// 重定向c库中scanf到USART1
int fgetc(FILE *f)
{
while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);//等待串口函数
return (int)USART_ReceiveData(USART1);
}
串口的设置
串口的时序和工作原理就不写了,主要写如何应用
串口的设置除了GPIO外,需要设置的参数有波特率、数据位、停止位,校验方式;
GPIO输出配置AF_PP复用推挽输出
GPIO出入配置IN_FLAOTING浮空输入
USART的配置为115200的波特率,8位数据长度,1位停止位,无校验,无硬件流控制
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
/* config USART1 clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);//打开GPIO和USART1时钟
/* USART1 GPIO config */
/* Configure USART1 Tx (PA.09) as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Configure USART1 Rx (PA.10) as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* USART1 mode config */
USART_InitStructure.USART_BaudRate = 115200;
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_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
/*使能串口1的接收中断 */
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
//使能串口1
USART_Cmd(USART1, ENABLE);
配置接收中断的中断等级
NVIC_InitTypeDef NVIC_InitStructure;
/* Configure the NVIC Preemption Priority Bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
/* Enable the USARTy Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
接收中断函数的实现
void USART1_IRQHandler(void)
{
uint8_t ch;
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
{
//ch = USART1-》DR;
ch = USART_ReceiveData(USART1);
printf( “%c”, ch ); //将受到的内容发送出去
}
}
发送数据的实现
/* 发送一个字节到串口 */
USART_SendData(USART1, (uint8_t) ch);
/*等待发送完成*/
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
实现调试的printf,scanf函数
实现printf和scanf函数必须要重写,并包含#include 《stdio.h》
/// 重定向c库中printf到USART1
int fputc(int ch, FILE *f)
{
USART_SendData(USART1, (uint8_t) ch);
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
return (ch);
}
/// 重定向c库中scanf到USART1
int fgetc(FILE *f)
{
while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);//等待串口函数
return (int)USART_ReceiveData(USART1);
}
举报