HAL库实现CAN通讯

HAL库可以便捷地实现CAN通讯。下面是一个简单的示例代码，展示如何使用HAL库发送CAN消息。

首先需要在CubeMX中启用CAN外设，并将其配置为所需的波特率、模式等。然后在代码中使用HAL_CAN_Init()函数初始化CAN外设。

/* CAN外设句柄 */
CAN_HandleTypeDef hcan1;

/* CAN消息发送缓冲区 */
uint8_t can_tx_buffer[8];

/* CAN消息数据 */
uint8_t can_data[8];

/* CAN消息标识符 */
uint32_t can_id;

/* CAN消息发送函数 */
void CAN_SendMessage(uint32_t id, uint8_t* data, uint8_t len) {
    /* 将数据复制到发送缓冲区 */
    memcpy(can_tx_buffer, data, len);

    /* 填充CAN消息结构体 */
    CAN_TxHeaderTypeDef tx_header;
    tx_header.StdId = id;
    tx_header.IDE = CAN_ID_STD;
    tx_header.RTR = CAN_RTR_DATA;
    tx_header.DLC = len;

    /* 发送CAN消息 */
    HAL_CAN_AddTxMessage(&hcan1, &tx_header, can_tx_buffer, NULL);
}

int main() {
    /* 初始化CAN外设 */
    HAL_CAN_Init(&hcan1);

    /* 设置CAN过滤器 */
    CAN_FilterTypeDef can_filter;
    can_filter.FilterBank = 0;
    can_filter.FilterMode = CAN_FILTERMODE_IDMASK;
    can_filter.FilterScale = CAN_FILTERSCALE_32BIT;
    can_filter.FilterIdHigh = 0x0000;
    can_filter.FilterIdLow = 0x0000;
    can_filter.FilterMaskIdHigh = 0x0000;
    can_filter.FilterMaskIdLow = 0x0000;
    can_filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
    can_filter.FilterActivation = ENABLE;
    HAL_CAN_ConfigFilter(&hcan1, &can_filter);

    /* 发送CAN消息 */
    can_id = 0x123;
    can_data[0] = 0x01;
    can_data[1] = 0x02;
    can_data[2] = 0x03;
    can_data[3] = 0x04;
    can_data[4] = 0x05;
    can_data[5] = 0x06;
    can_data[6] = 0x07;
    can_data[7] = 0x08;
    CAN_SendMessage(can_id, can_data, 8);

    while (1) {
        /* 等待CAN中断 */
        HAL_CAN_IRQHandler(&hcan1);
    }
}

在上面的代码中，CAN_SendMessage()函数用于发送CAN消息。首先将数据复制到发送缓冲区，然后填充CAN消息结构体，并使用HAL_CAN_AddTxMessage()函数发送CAN消息。

注意，为了接收CAN消息，需要在中断处理函数中使用HAL_CAN_GetRxMessage()函数读取CAN消息。具体细节请参考HAL库的文档和示例代码。