简介
本文记录一下stm32标准库实现串口发送功能和接收功能的接口函数。
轮询方式发送串口数据
1、标准库实现
void USART_Send_Byte(USART_TypeDef* USARTx, uint16_t Data)
{
USART_SendData(USARTx, Data);
while(USART_GetFlagStatus(USARTx, USART_FLAG_TXE)==RESET);
}
void USART_Send_String(USART_TypeDef* USARTx, char *str)
{
uint16_t i=0;
do
{
USART_Send_Byte(USARTx, *(str+i));
i++;
}
while(*(str + i) != '\0');
while(USART_GetFlagStatus(USARTx, USART_FLAG_TC)==RESET);
}
2、寄存器实现
void USART_Send_Byte(USART_TypeDef* USARTx, uint16_t Data)
{
while((USARTx->SR & USART_FLAG_TC) == RESET);
USARTx->DR = (uint8_t)Data;
return Data;
}
轮询方式接收串口数据
1、寄存器实现
void USART_Receive_Byte(USART_TypeDef* USARTx, uint16_t *Data)
{
while((USARTx->SR & USART_FLAG_RXNE) == RESET);
*Data = (uint16_t)USARTx->DR;
}
2、标准库实现
void USART_Receive_Byte(USART_TypeDef* USARTx, uint16_t *Data)
{
while(USART_GetFlagStatus(USARTx, USART_FLAG_RXNE)==RESET);
*Data = USART_ReceiveData(USARTx);
}
中断方式接收串口数据
#define Max_BUFF_Len 18
unsigned char Uart2_Buffer[Max_BUFF_Len];
unsigned int Uart2_Rx=0;
void USART2_IRQHandler()
{
if(USART_GetITStatus(USART2,USART_IT_RXNE) != RESET)
{
USART_ClearITPendingBit(USART2,USART_IT_RXNE);
Uart2_Buffer[Uart2_Rx] = USART_ReceiveData(USART2);
Uart2_Rx++;
if(Uart2_Buffer[Uart2_Rx-1] == 0x0a || Uart2_Rx == Max_BUFF_Len)
{
if(Uart2_Buffer[0] == '+')
{
printf("%s\r\n",Uart2_Buffer);
Uart2_Rx=0;
}
else
{
Uart2_Rx=0;
}
}
}
}
上述示例程序中一帧数据的头标志是字符+,尾标志是字符\n。
DMA方式接收串口数据
串口的IDLE(空闲中断)配合DMA实现串口接收数据(接收一帧后中断一次)
#define DMA_USART1_RECEIVE_LEN 18
void USART1_IRQHandler(void)
{
u32 temp = 0;
uint16_t i = 0;
if(USART_GetITStatus(USART1, USART_IT_IDLE) != RESET)
{
temp = USART1->SR;
temp = USART1->DR;
DMA_Cmd(DMA1_Channel5,DISABLE);
temp = DMA_USART1_RECEIVE_LEN - DMA_GetCurrDataCounter(DMA1_Channel5);
for (i = 0;i < temp;i++)
{
Uart2_Buffer[i] = USART1_RECEIVE_DMABuffer[i];
}
DMA_SetCurrDataCounter(DMA1_Channel5,DMA_USART1_RECEIVE_LEN);
DMA_Cmd(DMA1_Channel5,ENABLE);
}
}
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