USART2 / BOOT problem

[pietro2]

Posted on September 28, 2012 at 14:13

Hi! I'm working with a STM32F0-Discovery board + IAR IDE

After loading this code

...

 void USART_Configuration(void)

{ 

  

  /* Abilita clock GPIOA e DMA  */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA , ENABLE);

  

  /* Abilita clock USART2 APB  */

  RCC_APB2PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

  

  /* configurazione pin USART2   **************************************************/

 // GPIO_DeInit(GPIOA);

  

  /* Connette i pin PA14 e PA15 alla periferica USATR */

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource14, GPIO_AF_1);    

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource15, GPIO_AF_1); 

  

  /* Configura i pin come AF pushpull */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14 | GPIO_Pin_15 ;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_2;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

  GPIO_Init(GPIOA, &GPIO_InitStructure); 

  

  /* Configurazione USART2:

  - BaudRate = 115200 baud  

  - Word Length = 8 Bits

  - Stop Bit = 1 Stop Bit

  - Parity = No Parity

  - Hardware flow control disabled (RTS and CTS signals)

  - Receive and transmit enabled

  */

  

  USART_DeInit(USART2);

  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);

  USART_Cmd(USART2, ENABLE); 

}

...

the board works wrong, because i can't program anymore the board.

when i try a programming/bebugging session, i receive the seguent message

''Fatal error: ST LINK, No MCU device found.''

It' possible to restore the board?

#usart2-/-boot-problem

[Tesla DeLorean]

Posted on September 28, 2012 at 20:09

Because  PA14 is SWCLK, part of the debug interface

Pull the BOOT0 pin high, and restart the device, it will go into the system loader instead of your code, then erase your code.

[pietro2]

Posted on October 01, 2012 at 09:39

The original post was too long to process during our migration. Please click on the provided URL to read the original post. https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I6lr&d=%2Fa%2F0X0000000buz%2Feoxhu2AUDOaAo6XO3BNFejLSprz1t7iOMJRANo3ZQQs&asPdf=false

[Tesla DeLorean]

Posted on October 01, 2012 at 13:33

RCC_APB2PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); //??

APB1 surely

[pietro2]

Posted on October 01, 2012 at 13:57

Great! Works, thank you clive1