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STM32F0 USART1 not work

michelemancini2
Associate III
Posted on September 22, 2012 at 18:43

Hi, I have STM32F0 Discovery, I need send a char example 'A' in USART1 that use PA9 to TX.

The configuration are:

    /* Enable GPIO clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);   //PA9 ,PA10

  /* Enable USART clock */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

  /* Connect PXx to USARTx_Tx */

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_0);     //PA9 -> TX

  /* Connect PXx to USARTx_Rx */

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_0);    //PA10 -> RX  

  /* Configure USART Tx as alternate function push-pull */

  GPIO_InitStructure.GPIO_Pin = GPIO_PinSource9;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure USART Rx as alternate function push-pull */

  GPIO_InitStructure.GPIO_Pin = GPIO_PinSource10;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* USART configuration */

  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);    

  /* Enable USART */

  USART_Cmd(USART1, ENABLE);

And for trasmit:

      USART_SendData(USART1, (uint8_t) 'A');

      while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);

      while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);

But Not work, the arm run

correctly

but the output PA9 is null trasmit
2 REPLIES 2
Posted on September 23, 2012 at 00:30

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

..

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

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michelemancini2
Associate III
Posted on September 23, 2012 at 12:47

Yes!!! now work!! Thanks You!!!