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STM32F4 why I cant comunicate with USART1 ?

Question asked by karakaya.mehmet on Feb 23, 2013
Latest reply on Jun 24, 2013 by Clive One
hello forum ,

please have a look at my STM32F4 code - the USART1 interrupt never gets called
when a character arrives at the serial port
I am sure about my PC side program becouse it is tested with F103 before

void init_serp_1( void ) {
    RCC_APB1PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
  
  USART_InitStructure.USART_BaudRate = 9600;
  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(USART1, &USART_InitStructure);
    Tx_len = 0;
    Tx_ptr = 0;
    Rx_ptr = 0;
  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
  //*******************************************************
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
  
    GPIO_PinAFConfig(GPIOB,GPIO_PinSource6,GPIO_AF_USART1);
    GPIO_PinAFConfig(GPIOB,GPIO_PinSource7,GPIO_AF_USART1);
  //*******************************************************
  USART_Cmd(USART1,ENABLE);
  USART1->SR &= ~USART_FLAG_TC;           // clear interrupt
    }
  
//**************************
void USART1_IRQHandler(void)
{
  volatile unsigned int IIR;
    IIR = USART1->SR;
    if (IIR & USART_FLAG_RXNE) {                  // read interrupt
      USART1->SR &= ~USART_FLAG_RXNE;
        Rx_buffer[Rx_ptr] = USART_ReceiveData(USART1);
        Rx_ptr++ ; if (Rx_ptr > 511) {Rx_ptr=0;com0err=1;}
    if (ending_char()) do_instruction();
  }
    if (IIR & USART_FLAG_TC) {
        USART1->SR &= ~USART_FLAG_TC;             // clear interrupt
        if (Tx_ptr < Tx_len) {
        Tx_ptr++; send_char (Tx_buffer[Tx_ptr]);}
        else USART_ITConfig(USART1, USART_IT_TC, DISABLE);
}
}
//**********************************
void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
  
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
  /* Enable the USARTx Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

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