CAN通信是控制电机运动的重要通信方式之一，具体使用方法如下：

can.h文件与can.cpp的使用

can .h

#pragma once
#include "stm32f4xx_hal.h"
#include "stm32f4xx_hal_can.h"
#include <cstdlib>
#include <cstring>

class CAN
{
    public:
    void Init(CAN_TypeDef* instance);
    void InitFilter();
    HAL_StatusTypeDef Transmit(const uint32_t ID,
                               const uint8_t*const pData,
                               const uint8_t len = 8);
    CAN_HandleTypeDef hcan;
    uint8_t data[8][8];
    private:
    CanTxMsgTypeDef TxMessage;
    CanRxMsgTypeDef RxMessage;
};

extern CAN can1, can2;

can.cpp

#include "can.h"
#include "PID.h"

void CAN::Init(CAN_TypeDef* instance)
{
    hcan.Instance       = instance;
    hcan.Init.Prescaler = 6;
    hcan.Init.Mode      = CAN_MODE_NORMAL;
    hcan.Init.SJW       = CAN_SJW_1TQ;
    hcan.Init.BS1       = CAN_BS1_2TQ;
    hcan.Init.BS2       = CAN_BS2_4TQ;
    hcan.Init.TTCM      = DISABLE;
    hcan.Init.ABOM      = ENABLE;
    hcan.Init.AWUM      = ENABLE;
    hcan.Init.NART      = DISABLE;
    hcan.Init.RFLM      = DISABLE;
    hcan.Init.TXFP      = DISABLE;
    HAL_CAN_Init(&hcan);
    HAL_CAN_Transmit_IT(&hcan);
    HAL_CAN_Receive_IT(&hcan, CAN_FIFO0);
    InitFilter();
}
void CAN::InitFilter()
{
    //can1 &can2 use same filter config
    CAN_FilterConfTypeDef       CAN_FilterConfigStructure;

    CAN_FilterConfigStructure.FilterNumber         = 0;
    CAN_FilterConfigStructure.FilterMode           = CAN_FILTERMODE_IDMASK;
    CAN_FilterConfigStructure.FilterScale          = CAN_FILTERSCALE_32BIT;
    CAN_FilterConfigStructure.FilterIdHigh         = 0x0000;
    CAN_FilterConfigStructure.FilterIdLow          = 0x0000;
    CAN_FilterConfigStructure.FilterMaskIdHigh     = 0x0000;
    CAN_FilterConfigStructure.FilterMaskIdLow      = 0x0000;
    CAN_FilterConfigStructure.FilterFIFOAssignment = CAN_FilterFIFO0;
    //can1(0-13)和can2(14-27)分别得到一半的filter
    CAN_FilterConfigStructure.BankNumber = 0;
    CAN_FilterConfigStructure.FilterActivation = ENABLE;

    HAL_CAN_ConfigFilter(&hcan, &CAN_FilterConfigStructure);
    //filter config for can2 
    //can1(0-13)和can2(14-27)分别得到一半的filter
    CAN_FilterConfigStructure.FilterNumber = 14;
    HAL_CAN_ConfigFilter(&hcan, &CAN_FilterConfigStructure);

    hcan.pTxMsg = &TxMessage;
    hcan.pRxMsg = &RxMessage;
}

void HAL_CAN_MspInit(CAN_HandleTypeDef* hcan)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    if (hcan->Instance == CAN1)
    {
        /* Peripheral clock enable */
        __HAL_RCC_CAN1_CLK_ENABLE();
        __HAL_RCC_GPIOA_CLK_ENABLE();
        /**CAN1 GPIO Configuration
            PD0     ------> CAN1_RX
            PD1     ------> CAN1_TX*/
        GPIO_InitStruct.Pin = GPIO_PIN_11 | GPIO_PIN_12;
        GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
        GPIO_InitStruct.Pull = GPIO_NOPULL;
        GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
        GPIO_InitStruct.Alternate = GPIO_AF9_CAN1;
        HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
        /* Peripheral interrupt init */
        HAL_NVIC_SetPriority(CAN1_TX_IRQn, 1, 0);
        HAL_NVIC_EnableIRQ(CAN1_TX_IRQn);
        HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 0, 0);
        HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
    }
    else if (hcan->Instance == CAN2)
    {
        /* Peripheral clock enable */
        __HAL_RCC_CAN2_CLK_ENABLE();
        __HAL_RCC_GPIOB_CLK_ENABLE();
        /**CAN1 GPIO Configuration
            PB12     ------> CAN2_RX
            PB13     ------> CAN2_TX*/
        GPIO_InitStruct.Pin = GPIO_PIN_12 | GPIO_PIN_13;
        GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
        GPIO_InitStruct.Pull = GPIO_NOPULL;
        GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
        GPIO_InitStruct.Alternate = GPIO_AF9_CAN2;
        HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
        /* Peripheral interrupt init */
        HAL_NVIC_SetPriority(CAN2_TX_IRQn, 1, 0);
        HAL_NVIC_EnableIRQ(CAN2_TX_IRQn);
        HAL_NVIC_SetPriority(CAN2_RX0_IRQn, 0, 0);
        HAL_NVIC_EnableIRQ(CAN2_RX0_IRQn);
    }
}

extern "C" void CAN1_TX_IRQHandler()
{
    HAL_CAN_IRQHandler(&can1.hcan);
}
extern "C" void CAN1_RX0_IRQHandler()
{
    HAL_CAN_IRQHandler(&can1.hcan);
}
extern "C" void CAN2_TX_IRQHandler()
{
    HAL_CAN_IRQHandler(&can2.hcan);
}
extern "C" void CAN2_RX0_IRQHandler()
{
    HAL_CAN_IRQHandler(&can2.hcan);
}

HAL_StatusTypeDef CAN::Transmit(const uint32_t ID, const uint8_t*const pData, const uint8_t len)
{
    hcan.pTxMsg->StdId = ID;
    hcan.pTxMsg->IDE = CAN_ID_STD;
    hcan.pTxMsg->RTR = CAN_RTR_DATA;
    hcan.pTxMsg->DLC = len;
    memcpy(hcan.pTxMsg->Data, pData, len);
    return HAL_CAN_Transmit(&hcan, 10);
}

void HAL_CAN_RxCpltCallback(CAN_HandleTypeDef* hcan)
{
    if (hcan == &can1.hcan)memcpy(can1.data[hcan->pRxMsg->StdId - 0x201], hcan->pRxMsg->Data, sizeof(uint8_t) * 8);
    else memcpy(can2.data[hcan->pRxMsg->StdId - 0x201], hcan->pRxMsg->Data, sizeof(uint8_t) * 8);

    /*#### add enable can it again to solve can receive only one ID problem!!!####**/
    __HAL_CAN_ENABLE_IT(hcan, CAN_IT_FMP0);
}

​

将我们的项目文件添加如上两个文件，文件中包括CAN通信的收发方式，可以更方便我们使用CAN通信来进行电机代码的编写