can通信滤波器.c .h文件

以下是一个简单的CAN通信滤波器的C代码和头文件示例：

can_filter.h

#ifndef CAN_FILTER_H
#define CAN_FILTER_H

#include <stdint.h>

#define CAN_FILTER_NUM  4

typedef struct
{
    uint32_t id;    // CAN ID
    uint32_t mask;  // Mask for filtering
} can_filter_t;

void can_filter_init(void);
void can_filter_add(can_filter_t filter);
void can_filter_remove(uint8_t filter_idx);

#endif /* CAN_FILTER_H */

can_filter.c

#include "can_filter.h"
#include "stm32f4xx_hal.h"

static CAN_HandleTypeDef hcan;
static uint8_t filter_count = 0;
static uint32_t filter_id[CAN_FILTER_NUM];
static uint32_t filter_mask[CAN_FILTER_NUM];

void can_filter_init(void)
{
    hcan.Instance = CAN1;
    hcan.Init.Prescaler = 6;
    hcan.Init.Mode = CAN_MODE_NORMAL;
    hcan.Init.SyncJumpWidth = CAN_SJW_1TQ;
    hcan.Init.TimeSeg1 = CAN_BS1_7TQ;
    hcan.Init.TimeSeg2 = CAN_BS2_2TQ;
    hcan.Init.TimeTriggeredMode = DISABLE;
    hcan.Init.AutoBusOff = DISABLE;
    hcan.Init.AutoWakeUp = DISABLE;
    hcan.Init.AutoRetransmission = ENABLE;
    hcan.Init.ReceiveFifoLocked = DISABLE;
    hcan.Init.TransmitFifoPriority = DISABLE;

    if (HAL_CAN_Init(&hcan) != HAL_OK)
    {
        Error_Handler();
    }

    CAN_FilterTypeDef filter_config;

    filter_config.FilterIdHigh = 0x0000;
    filter_config.FilterIdLow = 0x0000;
    filter_config.FilterMaskIdHigh = 0x0000;
    filter_config.FilterMaskIdLow = 0x0000;
    filter_config.FilterFIFOAssignment = CAN_RX_FIFO0;
    filter_config.FilterBank = 0;
    filter_config.FilterMode = CAN_FILTERMODE_IDMASK;
    filter_config.FilterScale = CAN_FILTERSCALE_32BIT;
    filter_config.FilterActivation = ENABLE;

    if (HAL_CAN_ConfigFilter(&hcan, &filter_config) != HAL_OK)
    {
        Error_Handler();
    }
}

void can_filter_add(can_filter_t filter)
{
    if (filter_count >= CAN_FILTER_NUM)
    {
        return;
    }

    filter_id[filter_count] = filter.id;
    filter_mask[filter_count] = filter.mask;

    CAN_FilterTypeDef filter_config;

    filter_config.FilterIdHigh = (filter.id >> 16) & 0xFFFF;
    filter_config.FilterIdLow = filter.id & 0xFFFF;
    filter_config.FilterMaskIdHigh = (filter.mask >> 16) & 0xFFFF;
    filter_config.FilterMaskIdLow = filter.mask & 0xFFFF;
    filter_config.FilterFIFOAssignment = CAN_RX_FIFO0;
    filter_config.FilterBank = filter_count + 1;
    filter_config.FilterMode = CAN_FILTERMODE_IDMASK;
    filter_config.FilterScale = CAN_FILTERSCALE_32BIT;
    filter_config.FilterActivation = ENABLE;

    if (HAL_CAN_ConfigFilter(&hcan, &filter_config) != HAL_OK)
    {
        Error_Handler();
    }

    filter_count++;
}

void can_filter_remove(uint8_t filter_idx)
{
    if (filter_idx >= filter_count)
    {
        return;
    }

    filter_id[filter_idx] = 0;
    filter_mask[filter_idx] = 0;

    CAN_FilterTypeDef filter_config;

    filter_config.FilterIdHigh = 0x0000;
    filter_config.FilterIdLow = 0x0000;
    filter_config.FilterMaskIdHigh = 0x0000;
    filter_config.FilterMaskIdLow = 0x0000;
    filter_config.FilterFIFOAssignment = CAN_RX_FIFO0;
    filter_config.FilterBank = filter_idx + 1;
    filter_config.FilterMode = CAN_FILTERMODE_IDMASK;
    filter_config.FilterScale = CAN_FILTERSCALE_32BIT;
    filter_config.FilterActivation = DISABLE;

    if (HAL_CAN_ConfigFilter(&hcan, &filter_config) != HAL_OK)
    {
        Error_Handler();
    }

    for (uint8_t i = filter_idx; i < filter_count - 1; i++)
    {
        filter_id[i] = filter_id[i + 1];
        filter_mask[i] = filter_mask[i + 1];
    }

    filter_count--;
}