STM32 环回模式CANTX引脚上没有波形

只看该作者 · 2011-7-21 09:36

1、环回模式，也就是LOOPBACK模式下能够实现收发，让其一直发送数据，STM32的CANTX引脚上没有波形，不知道是什么问题？
2、我设置的CAN波特率为250Kbits，请问一下，在这个波特率下一直不停地循环发送数据，示波器能不能看到CANTX引脚上的波形？我的意思是会不会频率太高示波器无法看到波形？
请各位大侠帮帮我啊！
3、STM32，我用的can收发器为SN65HVD232
4、都说实现收发需要两个节点，我想请问一下，我只用STM32一直不停地发数据，没有接收端，这样CANTX上会有信号么？

只看该作者 · 2011-7-21 10:13

哥啊，我也在搞这个东西啊调不通
1.我的也没有
4.我环回正常，但是调成正常模式就一直发不出去数据

只看该作者 · 2011-7-21 10:16

跟2楼握爪，一起加油啊

只看该作者 · 2011-7-21 11:33

本帖最后由 Itachi80 于 2011-7-21 11:37 编辑

前段时间调过一下，用泰克示波器能看到明显的波形，我用的是PCA82C250，环回模式没测过，用两个节点测得

  /* Configure CAN pin: RX */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure CAN pin: TX */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

void CAN_Configuration(void)
{
  CAN_InitTypeDef       CAN_InitStructure;
  CAN_FilterInitTypeDef  CAN_FilterInitStructure;

  /* CAN register init */
  CAN_DeInit();
  CAN_StructInit(&CAN_InitStructure);

  /* CAN cell init */
  CAN_InitStructure.CAN_TTCM=DISABLE;
  CAN_InitStructure.CAN_ABOM=DISABLE;
  CAN_InitStructure.CAN_AWUM=DISABLE;
  CAN_InitStructure.CAN_NART=DISABLE;
  CAN_InitStructure.CAN_RFLM=DISABLE;
  CAN_InitStructure.CAN_TXFP=DISABLE;
  CAN_InitStructure.CAN_Mode=CAN_Mode_Normal ;
  CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;
  CAN_InitStructure.CAN_BS1=CAN_BS1_8tq;
  CAN_InitStructure.CAN_BS2=CAN_BS2_7tq;
  CAN_InitStructure.CAN_Prescaler=1;
  CAN_Init(&CAN_InitStructure);

  /* CAN filter init */
  CAN_FilterInitStructure.CAN_FilterNumber=1;
  CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;
  CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
  CAN_FilterInitStructure.CAN_FilterIdHigh=0x0000;
  CAN_FilterInitStructure.CAN_FilterIdLow=0x000;
  CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000;
  CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO0;
  CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
  CAN_FilterInit(&CAN_FilterInitStructure);

  /* CAN FIFO0 message pending interrupt enable */
  CAN_ITConfig(CAN_IT_FMP0, ENABLE);
}

只看该作者 · 2011-7-21 15:03

4# Itachi80
你好，可以看看你的完整么？

只看该作者 · 2011-7-21 15:04

4# Itachi80
打错了，可以看看你的完整程序么？

只看该作者 · 2011-7-21 15:06

:P 把你的完整程序贴上去让我们看看

只看该作者 · 2011-7-21 15:09

4# Itachi80
另外，stm32工作电压3.3v，PCA82C250工作电压5v，这样PCA82C250可以用在stm32的CAN上面么？

只看该作者 · 2011-7-21 15:44

/*******************************************************************************
* File Name       : main.c
* Author          : Guofeng Chen
* Date First Issued  : 2010.10.14
* Description       : Main program of the commnication between the PC and stm32
********************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x_lib.h"

/* Local includes ------------------------------------------------------------*/
/* Private typedef -----------------------------------------------------------*/
typedef enum {FAILED = 0, PASSED = !FAILED} TestStatus;

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
vu32 ret; /* for return of the interrupt handling */
volatile TestStatus TestRx;
ErrorStatus HSEStartUpStatus;

/* Private functions ---------------------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
void CAN_Configuration(void);

  int text_1=5,text_2=5;
  extern vu16  CAN_ID ;

/*******************************************************************************
* Function Name  : main
* Description : Main program
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
int main(void)
{

#ifdef DEBUG
  debug();
#endif
  CanTxMsg TxMessage;
  u32 i;
  /* System Clocks Configuration */
  RCC_Configuration();

  /* NVIC Configuration */
  NVIC_Configuration();

  /* GPIO ports pins Configuration */
  GPIO_Configuration();

  CAN_Configuration();

  while(1)
  {
for(i=0;i<0xffff;i++)  ;

  /* transmit 1 message */
  TxMessage.StdId=0x0002;
// TxMessage.ExtId=0x34;
  TxMessage.IDE=CAN_ID_STD;
  TxMessage.RTR=CAN_RTR_DATA;
  TxMessage.DLC=2;
  TxMessage.Data[0]=0xaa;
  TxMessage.Data[1]=0xaa;
  CAN_Transmit(&TxMessage);

  }
}

/*******************************************************************************
* Function Name  : RCC_Configuration
* Description : Configures the different system clocks.
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void RCC_Configuration(void)
{
  /* RCC system reset(for debug purpose) */
  RCC_DeInit();

  /* Enable HSE */
  RCC_HSEConfig(RCC_HSE_ON);

  /* Wait till HSE is ready */
  HSEStartUpStatus = RCC_WaitForHSEStartUp();

  if(HSEStartUpStatus == SUCCESS)
  {
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);

/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);

/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);

/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

/* Select HSE as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_HSE);

/* Wait till HSE is used as system clock source */
while(RCC_GetSYSCLKSource() != 0x04)
{
}
  }

  /* GPIOA and GPIOC clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA  | RCC_APB2Periph_GPIOC, ENABLE);

  /* CAN Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN, ENABLE);
}

/*******************************************************************************
* Function Name  : GPIO_Configuration
* Description : Configures the different GPIO ports.
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* Configure PC.06, PC.07, PC.08 and PC.09 as Output push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOC, &GPIO_InitStructure);

  /* Configure CAN pin: RX */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure CAN pin: TX */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
}

/*******************************************************************************
* Function Name  : NVIC_Configuration
* Description : Configures the NVIC and Vector Table base address.
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;

#ifdef  VECT_TAB_RAM
  /* Set the Vector Table base location at 0x20000000 */
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif

  /* enabling interrupt */
  NVIC_InitStructure.NVIC_IRQChannel=USB_LP_CAN_RX0_IRQChannel;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

/*******************************************************************************
* Function Name  : CAN_Interrupt
* Description : Configures the CAN and transmit and receive by interruption
* Input       : None
* Output       : None
* Return       : PASSED if the reception is well done, FAILED in other case
*******************************************************************************/
void CAN_Configuration(void)
{
  CAN_InitTypeDef       CAN_InitStructure;
  CAN_FilterInitTypeDef  CAN_FilterInitStructure;

  /* CAN register init */
  CAN_DeInit();
  CAN_StructInit(&CAN_InitStructure);

  /* CAN cell init */
  CAN_InitStructure.CAN_TTCM=DISABLE;
  CAN_InitStructure.CAN_ABOM=DISABLE;
  CAN_InitStructure.CAN_AWUM=DISABLE;
  CAN_InitStructure.CAN_NART=DISABLE;
  CAN_InitStructure.CAN_RFLM=DISABLE;
  CAN_InitStructure.CAN_TXFP=DISABLE;
  CAN_InitStructure.CAN_Mode=CAN_Mode_Normal ;//LoopBack
  CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;
  CAN_InitStructure.CAN_BS1=CAN_BS1_8tq;
  CAN_InitStructure.CAN_BS2=CAN_BS2_7tq;
  CAN_InitStructure.CAN_Prescaler=1;
  CAN_Init(&CAN_InitStructure);

  /* CAN filter init */
  CAN_FilterInitStructure.CAN_FilterNumber=1;
  CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;
  CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
  CAN_FilterInitStructure.CAN_FilterIdHigh=0x0000;
  CAN_FilterInitStructure.CAN_FilterIdLow=0x000;
  CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000;
  CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO0;
  CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
  CAN_FilterInit(&CAN_FilterInitStructure);

  /* CAN FIFO0 message pending interrupt enable */
  CAN_ITConfig(CAN_IT_FMP0, ENABLE);

}

#ifdef  DEBUG
/*******************************************************************************
* Function Name  : assert_failed
* Description : Reports the name of the source file and the source line number
*                where the assert error has occurred.
* Input       : - file: pointer to the source file name
*                - line: assert error line source number
* Output       : None
* Return       : None
*******************************************************************************/
void assert_failed(u8* file, u32 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)
  {
  }
}
#endif
/******************* (C) COPYRIGHT 2007 STMicroelectronics *****END OF FILE****/