[经验]

【CW32饭盒派开发板试用体验】串口试验

华仔stm32

2023-5-28 10:53:28

335 CW32

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 */
}