AT32F407VGT7的CAN2是不是有问题啊？不发送也有波形

发表于 2021-7-9 08:25

CAN2初始化后发送一次数据，用示波器测量始终有波行输出，频率有规则40K，驱动是按官方CAN1的改的，调试多次未解决，怀疑是否芯片问题。

发表于 2021-7-9 08:33

示波器测量图片

发表于 2021-7-9 08:34

GPIO_InitType GPIO_InitStructure;

GPIO_InitStructure.GPIO_Pins = GPIO_Pins_13;
GPIO_InitStructure.GPIO_MaxSpeed = GPIO_MaxSpeed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pins = GPIO_Pins_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_PU;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//
RCC_APB1PeriphClockCmd(RCC_APB1PERIPH_CAN2, ENABLE);
引脚配置

发表于 2021-7-9 08:35

CAN_InitType  CAN_InitStructure;
CAN_FilterInitType    CAN_FilterInitStructure = {0};

CAN_InitStructure.CAN_TTC = DISABLE;
CAN_InitStructure.CAN_ABO = ENABLE;
CAN_InitStructure.CAN_AWU = ENABLE;
CAN_InitStructure.CAN_NART = DISABLE;
CAN_InitStructure.CAN_RFL = DISABLE;
CAN_InitStructure.CAN_TFP = DISABLE;
CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;

switch (bulv)
  {
    case 1000:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_8tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;
CAN_InitStructure.CAN_Prescaler = 10;
}
    break;
case 800:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_10tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_2tq;
CAN_InitStructure.CAN_Prescaler = 10;
}
    break;
    case 500:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_2tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_1tq;
CAN_InitStructure.CAN_Prescaler = 60;
}
    break;
    case 250:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_8tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;
CAN_InitStructure.CAN_Prescaler = 40;
}
    break;
case 100:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;
CAN_InitStructure.CAN_Prescaler = 60;
}
    break;
case 50:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;
CAN_InitStructure.CAN_Prescaler = 120;
}
    break;
case 20:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_14tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;
CAN_InitStructure.CAN_Prescaler = 300;
}
    break;
    default:
{
CAN_InitStructure.CAN_BS1 = CAN_BS1_8tq;
CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;
CAN_InitStructure.CAN_Prescaler =10;
}
    break;
  }

CAN_Init(CAN2, &CAN_InitStructure);    ///<SYSCLK=240M,  APB1CLK=120M, CAN Baudrate=（240/2）*1000K）/（（1+9）*（3+7+2）） = 1000K

  CAN_FilterInitStructure.CAN_FilterNumber=0;
CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;
CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
CAN_FilterInitStructure.CAN_FilterIdHigh=0x0;
CAN_FilterInitStructure.CAN_FilterIdLow=0x0;
CAN_FilterInitStructure.CAN_FilterMskIdHigh=0x0;
CAN_FilterInitStructure.CAN_FilterMskIdLow=0x0;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO0;
CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
CAN_FilterInit(CAN2, &CAN_FilterInitStructure);

  CAN_INTConfig(CAN2,CAN_INT_RFP0,ENABLE);
CAN配置

发表于 2021-7-9 08:35

NVIC_InitType NVIC_InitStructure = {0};

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel = CAN2_RX0_IRQn ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x10;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
CAN2中断配置

发表于 2021-7-9 09:30

fuquan19801117 发表于 2021-7-9 08:33
示波器测量图片

CAN没输出但是pin有输出的话，首先排除一下这个pin上其他功能有没有开起来。你这边PB12/PB13的话可能是TMR1或SPI2。你可以看看数据手册的引脚定义这一节，看看有没有别的功能开启。

发表于 2021-7-9 09:59

问题找到了，借鉴了STM32的，查到的

发表于 2021-7-10 13:58

是什么原因呢？

发表于 2021-7-10 14:18

没接负载的话自动重传开着没ACK，就会一直重发

发表于 2022-9-7 21:39

楼主，是因为什么原因啊？

发表于 2022-10-5 21:04

楼主原因是啥啊？

[AT32F407] AT32F407VGT7的CAN2是不是有问题啊？不发送也有波形

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