USART communication avec un STM32f1xx

Je cherche à atteindre un USART de la communication. J'ai donc brancher le RX de mon STM32f1 avec son TX.
Aussi j'écris un programme pour cette communication. Ce code est composé des éléments suivants:

1. RCC configuration
2. GPIO configuration
3. USART configuration
4. D'envoyer et de recevoir d'une chaîne
5. Comparaison entre les envoyés de la chaîne et de la chaîne reçue
6. Test si la communication a réussi => LED4 tour sur le reste de la LED3 tour sur

Le problème est dans tous les cas, la LED3 s'allume. Cela signifie que la transmission de données a échoué.

Avec mon IDE (IAR Embedded Workbench) je compile ce code de programme:

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"
#include "stm32_eval.h"
/* Private typedef -----------------------------------------------------------*/
typedef enum { FAILED = 0, PASSED = !FAILED} TestStatus;
/* Private define ------------------------------------------------------------*/
#define USARTy                   USART1
#define USARTy_GPIO              GPIOA /* PORT name*/
#define USARTy_CLK               RCC_APB2Periph_USART1
#define USARTy_GPIO_CLK          RCC_APB2Periph_GPIOA
#define USARTy_RxPin             GPIO_Pin_10/* pin Rx name*/ 
#define USARTy_TxPin             GPIO_Pin_9 /* pin Tx name*/
#define USARTz                   USART2
#define USARTz_GPIO              GPIOA/* PORT name*/
#define USARTz_CLK               RCC_APB1Periph_USART2
#define USARTz_GPIO_CLK          RCC_APB2Periph_GPIOA
#define USARTz_RxPin             GPIO_Pin_3/* pin Rx name*/
#define USARTz_TxPin             GPIO_Pin_2/* pin Tx name*/
#define TxBufferSize   (countof(TxBuffer))
/* Private macro -------------------------------------------------------------*/
#define countof(a)   (sizeof(a) / sizeof(*(a)))
/* Private variables ---------------------------------------------------------*/
USART_InitTypeDef USART_InitStructure;
uint8_t TxBuffer[] = "Bufferrr";
uint8_t RxBuffer[8];
__IO uint8_t TxConteur = 0, RxConteur = 0;
volatile TestStatus TransferStatus = FAILED;  
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength);
__IO uint8_t index = 0;
GPIO_InitTypeDef GPIO_InitStructure;
int main(void)
{
STM_EVAL_LEDInit(LED1);
STM_EVAL_LEDInit(LED2);
STM_EVAL_LEDInit(LED3);
STM_EVAL_LEDInit(LED4);
/* System Clocks Configuration */
RCC_Configuration();
/* Configure the GPIO ports */
GPIO_Configuration();
USART_InitStructure.USART_BaudRate = 230400 /*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;
/* Configure USARTy */
USART_Init(USART1,&USART_InitStructure);
/* Enable the USARTy */
USART_Cmd(USART1,ENABLE);
while(TxConteur < TxBufferSize)
{  
/* Send one byte from USARTy to USARTz */
USART_SendData(USARTy, TxBuffer[TxConteur++]);
/* Loop until USARTy DR register is empty */ 
while(USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET)
{
}
/* Store the received byte in RxBuffer */
RxBuffer[RxConteur++] = USART_ReceiveData(USARTy) & 0xFF;
}  
/* Check the received data with the send ones */
TransferStatus = Buffercmp(TxBuffer, RxBuffer, TxBufferSize);
/* TransferStatus = FAILED, if the data transmitted from USARTy and 
received by USARTz are different */
if (TransferStatus == FAILED)
{
STM_EVAL_LEDOn(LED3);
}
else 
{
STM_EVAL_LEDOn(LED4);
}
while (1)
{
}
}
void RCC_Configuration(void)
{    
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC , ENABLE);
}
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure1,GPIO_InitStructure2;
/* Configure USARTy Rx as input floating */
GPIO_InitStructure1.GPIO_Pin =GPIO_Pin_10;
GPIO_InitStructure1.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure1.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure1);
/* Configure USARTy Tx as alternate function push-pull */
GPIO_InitStructure2.GPIO_Pin =GPIO_Pin_9;
GPIO_InitStructure2.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure2);
/* Configure USARTz Tx as alternate function push-pull */
}
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
while(BufferLength--)
{
if(*pBuffer1 != *pBuffer2)
{
return FAILED;
}
pBuffer1++;
pBuffer2++;
}
return PASSED;  
}

OriginalL'auteur Kallel Omar | 2012-12-28