Electrical – How to use both usart1 and usart2 together in stm32f103

cmicrocontrollerstm32stm32f10xuart

How can I use both usart1 (PA.09, PA.10) and usart2 (PA.02,PA.03) in a same time?

I can send and receive data via Usart1 but when I enable usart2 , no data could not be sent by usart1 and usart2!

I use stm32f103c8t6.

Code:

int main(void)
{
    GPIO_CONFIG();

    /* Configure the USART1 */          
    USART_Configuration();      
    printf("\r\nWELCOME usart1\r\n");// data received by terminal 1

    /* Configure the USART2 */              
    USART2_Configuration();
    USART2_Send("Hello usart2",9);// data not received by terminal 2

    printf("\r\nWELCOME usart1\r\n");// data not received by terminal 1

    while(1){}

}

usart1 and usart2 configurations are the same, and I use 2 terminal for each usart separately.

Edit:
Both usart1 and 2 configuration are the same,
usart2 configs in 'usart2.c' :

void USART2_IRQHandler(void)
{
  uint8_t receivedChar;  
   if ((USART2->SR & USART_FLAG_RXNE) != (u16)RESET)           
   {          
        receivedChar = USART_ReceiveData(USART2);
        if(USART2_Rx_BufferIndex == Max_Rx_Buffer_Size ||    USART2_Rx_BufferIndex==USART2_Desired_Buffer_Size ||  receivedChar=='\n')
        {
            USART2_RxBuffer[USART2_Rx_BufferIndex] = receivedChar;
                          USART2_flag = 1;
        }
        else
        {
            USART2_RxBuffer[USART2_Rx_BufferIndex++] = receivedChar;
        }
        USART2_RxBuffer[USART2_Rx_BufferIndex] = '\0';
    }           
}


 void USART2_Recieve(uint16_t size)
{       


 if(size < Max_Rx_Buffer_Size)
 {
    USART2_Desired_Buffer_Size = size;
 }
 else
 {
    USART2_Desired_Buffer_Size = Max_Rx_Buffer_Size;
 }
 USART2_flag = 0;
 while(USART2_flag == 0);           
 USART2_recievedData = USART2_RxBuffer;
 USART2_recievedData[USART2_Rx_BufferIndex+1] ='\0';
 USART2_Rx_BufferIndex=0;
}

void USART2_RecieveFix(uint16_t size)
{
    if(size < Max_Rx_Buffer_Size)
    {
        USART2_Desired_Buffer_Size = size;
    }
    else
    {
        USART2_Desired_Buffer_Size = Max_Rx_Buffer_Size;
    }
  USART2_Rx_BufferIndex = 0;
    while(USART2_Rx_BufferIndex < size)
    {
        USART2_flag = 0;
        while(USART2_flag ==0);
        USART2_Rx_BufferIndex++;
    }


  USART2_recievedData = USART2_RxBuffer;
    USART2_recievedData[USART2_Rx_BufferIndex+1] ='\0';
    USART2_Rx_BufferIndex=0;            
}
char *USART2_GetReceivedData(void)
{
    return USART2_recievedData;
}



    void USART2_NVIC_Configuration(void){
      NVIC_InitTypeDef NVIC_InitStructure;

  /* Enable the USARTx Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}



void USART2_Configuration(void){

    USART_InitTypeDef USART_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_Rx | USART_Mode_Tx;   
  USART_Init(USART2, &USART_InitStructure);
  /* Enable USART2 */
  USART_Cmd(USART2, ENABLE);



    USART2_NVIC_Configuration();

    /* Enable the USART2 Receive interrupt: this interrupt is generated when the
  USART2 receive data register is not empty */
  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
}


void USART2_Send(unsigned char *pucBuffer, unsigned long ulCount)
{
    //
    // Loop while there are more characters to send.
    //

    while(ulCount--)
    {
        USART_SendData(USART2, *pucBuffer++);// Last Version     USART_SendData(USART2,(uint16_t) *pucBuffer++);
        /* Loop until the end of transmission */
        while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET)
        {
        }
    }

}

and in 'main.c'

void GPIO_CONFIG(void)
   {
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);
      /* Configure USART1 Tx (PA.09) and UARTT2 Tx (PA.02) as alternate   function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure USART1 Rx (PA.10) and USART2 Rx (PA.03) as input floating */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
 }

Best Answer

The problem was in the GPIO_CONFIG(void) function, I have to use RCC_APB2PeriphClockCmd function for usart1 and RCC_APB1PeriphClockCmd for usart2. Since usart1 belongs to APB2PeriphClock and usart2 belongs to RCC_APB1PeriphClock.So the final solution is :

void GPIO_CONFIG(void)
 {
   GPIO_InitTypeDef GPIO_InitStructure;    
   // enable uart 1 preph clock mode
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA ,     ENABLE);

    // enable uart 2 preph clock mode
   RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);

 /* Configure USART1 Tx (PA.09) and UARTT2 Tx (PA.02) as alternate        function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure USART1 Rx (PA.10) and USART2 Rx (PA.03) as input floating */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
}