CH32V305 使用 UART3 的例子

根据 Ch32V307 的 “USART_Printf：串口打印调试例程” 修改而来。对于Ch32V305来说，UART3 在电路图如下位置：

Arduino 代码如下：

void zUSART_Printf_Init(uint32_t baudrate)
{
    GPIO_InitTypeDef  GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    USART_InitStructure.USART_BaudRate = baudrate;
    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_Tx;

    USART_Init(USART3, &USART_InitStructure);
    USART_Cmd(USART3, ENABLE);

}

 void OutUart(char *buf, int size)
{
    for(int i = 0; i < size; i++)
    {
        while(USART_GetFlagStatus(USART3, USART_FLAG_TC) == RESET);
        USART_SendData(USART3, *buf++);
    }
}

void setup() {
  zUSART_Printf_Init(115200);
}

void loop() {
  char sMsg[]="www.lab-z.com";
  OutUart(sMsg,sizeof(sMsg));
  delay(1000);
}

// USART3 缓冲区最大长度
#define RXBUFFER3SIZE    100
// USART3 缓冲区
u8 RxBuffer3[RXBUFFER3SIZE];
// USART3 缓冲区内数据长度
volatile u8 RxCnt3 = 0;

#ifdef __cplusplus
extern "C" {
#endif // __cplusplus
void USART2_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
void USART3_IRQHandler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
#ifdef __cplusplus
} // extern "C"
#endif // __cplusplus

/*********************************************************************
   @fn      USARTx_CFG

   @brief   Initializes the USART2 & USART3 peripheral.

   @return  none
*/
void USARTx_CFG(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure = {0};
  USART_InitTypeDef USART_InitStructure = {0};
  NVIC_InitTypeDef  NVIC_InitStructure = {0};

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  /* USART3 TX-->B.10  RX-->B.11 */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  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_Tx | USART_Mode_Rx;

  USART_Init(USART3, &USART_InitStructure);
  USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

  NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  
  USART_Cmd(USART3, ENABLE);
}

void setup() {
  // 这次的测试是从 USART3 接收，然后将收到的数据从 USART1 送出
  Serial.begin(115200);
  Serial.println("Start");
  USARTx_CFG(); 
  Serial.println("Init Done");
}

void loop() {
  if (RxCnt3!=0) {
      for (int i=0;i<RxCnt3;i++) {
          Serial.write(RxBuffer3[i]);
        }
      RxCnt3=0;
    }
   
   delay(1000);
}

/*********************************************************************
 * @fn      USART3_IRQHandler
 *
 * @brief   This function handles USART3 global interrupt request.
 *
 * @return  none
 */
void USART3_IRQHandler(void)
{
    if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
    {
        RxBuffer3[RxCnt3++] = USART_ReceiveData(USART3);
    }
}