c++ - STM32F103 微 Controller CAN 消息

Question

我想知道是否有人熟悉 STM32f10x 微 Controller ？

如果是这样，我在配置 CAN 驱动程序时遇到了一些问题。我可以运行设置为loop_Back模式的演示代码，但我无法让Normal_Mode工作。

我通读了所有数据表，除了 CAN_MSR 寄存器中的 INAK 永远不会重置为 0 之外，所有内容都配置正确。如果需要，我可以提供更多详细信息，但首先我需要知道是否有人曾经使用过STM32F103 微 Controller 和 CAN 消息。

Answer 1

您将 Tx 引脚设置为 Out_PP，但应将其配置为备用功能。下面是我在 STM32F107 上的 CAN 初始化代码。我将其从现有项目中复制粘贴并删除，因此不需要某些内容(例如并非所有 GPIO 都需要启用)。另请注意，我使用重映射功能将 CAN Rx 和 Tx 引脚放在端口 D 上。

使用 72 MHz 时钟时，此配置将总线速度设置为 500 kbit/s。

Int HardwareInit(void)
{
    Int retval = 0;

    GPIO_InitTypeDef GPIO_InitStructure;
    NVIC_InitTypeDef   NVIC_InitStructure;
    SPI_InitTypeDef SPI_InitStructure;
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    TIM_OCInitTypeDef  TIM_OCInitStructure;
    ADC_InitTypeDef ADC_InitStructure;
    DMA_InitTypeDef DMA_InitStructure;
    CAN_InitTypeDef        CAN_InitStructure;
    CAN_FilterInitTypeDef  CAN_FilterInitStructure;

    SystemInit();

    /* Enable GPIOs clocks */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC |
                           RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE| RCC_APB2Periph_AFIO, ENABLE);

    /* 2 bit for pre-emption priority, 2 bits for subpriority */
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);


    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOD, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);

    CAN_DeInit(CAN1);
    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 = ENABLE;
    CAN_InitStructure.CAN_RFLM = DISABLE;
    CAN_InitStructure.CAN_TXFP = ENABLE;
    CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
    CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;
    CAN_InitStructure.CAN_BS1 = CAN_BS1_3tq;
    CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;
    CAN_InitStructure.CAN_Prescaler = 8;
    CAN_Init(CAN1, &CAN_InitStructure);

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

    CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);

    NVIC_InitStructure.NVIC_IRQChannel = CAN1_RX0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0xFF;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0xFF;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    /* Configure CAN pin: RX */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    /* Configure CAN pin: TX */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    GPIO_PinRemapConfig(GPIO_Remap2_CAN1 , ENABLE);


    return retval;
}

发送消息可以这样完成:

CanTxMsg TxMessage;
Nat8 mailbox;

TxMessage.StdId = 0x7E5;
TxMessage.RTR=CAN_RTR_DATA;
TxMessage.IDE=CAN_ID_STD;

TxMessage.Data[0] = 0x04;
TxMessage.Data[1] = (state) ? 0x01 : 0x00;
TxMessage.Data[2] = 0x00;
TxMessage.Data[3] = 0x00;
TxMessage.Data[4] = 0x00;
TxMessage.Data[5] = 0x00;
TxMessage.Data[6] = 0x00;
TxMessage.Data[7] = 0x00;
TxMessage.DLC = 8;

do
{
    mailbox = CAN_Transmit(CAN1, &TxMessage);
}
while (mailbox == CAN_NO_MB);

通过 IRQ 完成接收:

CanRxMsg rx_message;
CAN_Receive(CAN1, CAN_FIFO0, &rx_message);