(资料图片)

串口选择

示例给出的是串口的，因为今天回老家，带的杜绑线是公对母的，不能接串口1，所以选择串口2，即PA2--TX，PA3--RX。

初始化串口

初始化UART2的时钟：__RCC_UART2_CLK_ENABLE();初始化GPIOA外设时钟：RCC_AHBPeriphClk_Enable( RCC_AHB_PERIPH_GPIOA, ENABLE);复用PA2为UART2TX： PA02_AFx_UART2TXD();复用PA3为UART2RX：PA03_AFx_UART2RXD();初始化PA2为高速输出模式：

GPIO_InitStructure.Pins = GPIO_PIN_2; //PA2  GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;  GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;  GPIO_Init(CW_GPIOA, &GPIO_InitStructure);

初始化PA3为上拉输入：

GPIO_InitStructure.Pins = GPIO_PIN_3; //PA3  GPIO_InitStructure.Mode = GPIO_MODE_INPUT_PULLUP;  GPIO_Init(CW_GPIOA, &GPIO_InitStructure);

初始化UART2配置为9600波特率：

USART_InitStructure.USART_BaudRate= 9600;  USART_InitStructure.USART_Over = USART_Over_16;  USART_InitStructure.USART_Source = USART_Source_PCLK;  USART_InitStructure.USART_UclkFreq = 64000000;  USART_InitStructure.USART_StartBit = USART_StartBit_FE;  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(CW_UART2, &USART_InitStructure);

使能中断输入

//使能UARTx RC中断  USART_ITConfig(CW_UART2, USART_IT_RC, ENABLE);  //优先级，无优先级分组  NVIC_SetPriority(UART2_IRQn, 0);  //UARTx中断使能  NVIC_EnableIRQ(UART2_IRQn);

中断接收函数，主要功能为判断接收到的第一位是否为0，第二位是否为1，如果总接收长度为4位，测翻转LED4，具体代码如下：

void UART2_IRQHandler(void){  /* USER CODE BEGIN */  unsigned char TxRxBuffer;  if(USART_GetITStatus(CW_UART2, USART_IT_RC) != RESET)  { USART_ClearITPendingBit(CW_UART2, USART_IT_RC);     TxRxBuffer = USART_ReceiveData_8bit(CW_UART2);rec[re_count]=TxRxBuffer; if (re_count == 0&&rec[0]==0x00){          rev_start=1;re_count++;}else if(rev_start==1){if(re_count==1&&rec[1]!=0x01){re_count=0;rev_start=0;}else if(re_count==4)           //计算总个数，0-4       {check_flag=1;re_count=0;rev_start=0;}  //如果对，那么将标志位置1，并清除里面的值从新接收else   re_count++;}  }  /* USER CODE END */}

实现效果，下载后，串口接收到0x00 0x01 0x02 0x03 ,HEX发送00 01 02 03 可以实现LED4的翻转：

审核编辑：汤梓红