STM32F4 problem with USART1 INTERRUPT

[Gigli.Dario]

Posted on February 19, 2013 at 21:52

Hi guys,

I have a problem with my new schede STM32F407VG. Until now I have been used the STM32F100B so now I'm adapting the code that I wrote. Part of my code is USART with interrupt, so I have wrote a code that read from USART1 (pin rx P10 and pin tx P9) and when the buffer is full the tx interrupt is ENABLE. I think that the configuration GPIO is wrong because I have modified only this part. If I send a string by Terminal I receive different data for example if I send sasdas  I receive {\xfe}{\xfe}{\xfe}{\xf0}{\xfe}, I checked the baudrate on the Terminal and it is the same of the USART.I prefix that the code works on the STM32F100B, where the GPIO configuration is:   

 GPIO_InitTypeDef GPIO_InitStructure;

  /* Configure USART Tx as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(GPIOA, &GPIO_InitStructure);   /* Configure USART Rx as input floating */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; // PA.10 USART1.RX  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  GPIO_Init(GPIOA, &GPIO_InitStructure);How is the GPIO configuration for the STM32F4?? I'm very confused.The code write for the STM32F4 is this, where do I err???

/* Includes ------------------------------------------------------------------*/

#include ''stm32f4xx.h''#include ''stm324xg_eval.h''char StringLoop[6];/**************************************************************************************/ void RCC_Configuration(void){  /* Enable GPIO clock */  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);   /* Enable UART clock */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);} /**************************************************************************************/ void GPIO_Configuration(void){    GPIO_InitTypeDef GPIO_InitStructure; // Pin 10 Rx GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_USART1); // Pin 9 Tx GPIO_PinAFConfig( GPIOA, GPIO_PinSource9, GPIO_AF_USART1);  /* Configure USART Tx as alternate function  */  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  //GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

// 

Is it right??

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(GPIOA, &GPIO_InitStructure);  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//// 

Is it right??  Should it be IN FLOATING????

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;  GPIO_Init(GPIOA, &GPIO_InitStructure);  } /**************************************************************************************/ void USART_Configuration(void){  USART_InitTypeDef USART_InitStructure;  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 configuration */  USART_Init(USART1, &USART_InitStructure);  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);  /* Enable the USART1 */  USART_Cmd(USART1, ENABLE);    } /**************************************************************************************/ void NVIC_Configuration(void){  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);     NVIC_InitTypeDef NVIC_InitStructure; // Configure the NVIC Preemption Priority Bits NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);  /* Enable the USART1 Interrupt */  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  NVIC_Init(&NVIC_InitStructure);} /**************************************************************************************/int main(void){  RCC_Configuration();   GPIO_Configuration();   NVIC_Configuration();   USART_Configuration();  while(1){  }  }/**************************************************************************************/void USART1_IRQHandler(void){  static int tx_index = 0;  static int rx_index = 0;  // Interrupt rx if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)   {    StringLoop[rx_index++] = USART_ReceiveData(USART1);    if (rx_index >= (sizeof(StringLoop) - 1))    { rx_index = 0;      USART_ITConfig(USART1, USART_IT_TXE, ENABLE);    }  } // Interrupt tx  if (USART_GetITStatus(USART1, USART_IT_TXE) != RESET)   {    USART_SendData(USART1, StringLoop[tx_index++]);     if (tx_index >= (sizeof(StringLoop) - 1))    {tx_index = 0;          USART_ITConfig(USART1, USART_IT_TXE, DISABLE);}  }}   /**************************************************************************************/#ifdef  USE_FULL_ASSERT/**  * @brief  Reports the name of the source file and the source line number  *         where the assert_param error has occurred.  * @param  file: pointer to the source file name  * @param  line: assert_param error line source number  * @retval None  */void assert_failed(uint8_t* file, uint32_t line){  /* User can add his own implementation to report the file name and line number,     ex: printf(''Wrong parameters value: file %s on line %d\r\n'', file, line) */   /* Infinite loop */  while (1)  {  }}#endifTHANK!!

[Tesla DeLorean]

Posted on February 20, 2013 at 01:10

USART1 PA9/PA10 is problematic on the STM32F4-Discovery due to a large bulk capacitor.

This should demonstrate the basic pin setup (GPIO and AF pin source mux)

// STM32 USART IRQ TX/RX Loop (USART3 Tx PD.8, Rx PD.9) STM32F4 Discovery - sourcer32@gmail.com
#include ''stm32f4_discovery.h''
volatile char StringLoop[] = ''The quick brown fox jumps over the lazy dog

'';
/**************************************************************************************/
void RCC_Configuration(void)
{
/* --------------------------- System Clocks Configuration -----------------*/
/* USART3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
/* GPIOD clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
}
/**************************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*-------------------------- GPIO Configuration ----------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Connect USART pins to AF */
GPIO_PinAFConfig(GPIOD, GPIO_PinSource8, GPIO_AF_USART3);
GPIO_PinAFConfig(GPIOD, GPIO_PinSource9, GPIO_AF_USART3);
}
/**************************************************************************************/
void USART3_Configuration(void)
{
USART_InitTypeDef USART_InitStructure;
/* USARTx configuration ------------------------------------------------------*/
/* USARTx configured as follow:
- BaudRate = 9600 baud
- Word Length = 8 Bits
- One Stop Bit
- No parity
- Hardware flow control disabled (RTS and CTS signals)
- Receive and transmit enabled
*/
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(USART3, &USART_InitStructure);
USART_Cmd(USART3, ENABLE);
 USART_ITConfig(USART3, USART_IT_RXNE | USART_IT_TXE, ENABLE);

 }
/**************************************************************************************/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Configure the NVIC Preemption Priority Bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
/* Enable the USART3 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************************/
void USART3_IRQHandler(void)
{
static int tx_index = 0;
static int rx_index = 0;
if (USART_GetITStatus(USART3, USART_IT_TXE) != RESET) // Transmit the string in a loop
{
USART_SendData(USART3, StringLoop[tx_index++]);
if (tx_index >= (sizeof(StringLoop) - 1))
tx_index = 0;
}
if (USART_GetITStatus(USART3, USART_IT_RXNE) != RESET) // Received characters modify string
{
StringLoop[rx_index++] = USART_ReceiveData(USART3);
if (rx_index >= (sizeof(StringLoop) - 1))
rx_index = 0;
}
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
NVIC_Configuration();
USART3_Configuration();
while(1); // Don't want to exit
}
/**************************************************************************************/

[Gigli.Dario]

Posted on February 20, 2013 at 11:03

Thank you, I have just solved the problem. It isn't only due to ''

USART1 PA9/PA10 is problematic on the STM32F4-Discovery due to a large bulk capacitor

'' , in fact I tryed to use another USART but I had the same problem. It was due to HSE_VALUE that in my old schede STM32F100B is 8MHz but in the new STM32F4 is 25MHz , so I changed it in 8 MHz and now the USART1 PA6/PA7 finally works.THANK AGAIN

[Tesla DeLorean]

Posted on February 20, 2013 at 13:22

The STM32F4-Discovery uses an 8 MHz crystal, HSE_VALUE always needs to reflect the hardware on your board. For other boards posting to the ''STM32 Discovery'' forum seems a bit odd, in the future posting to the ''STM32'' generic forum would be helpful, along with specific details about the board being used. Thanks.