總結一些最近做項目對CAN通信的過濾器配置的理解；

這里我使用STM32F105系列的芯片，有2路CAN，我使用的是CAN2，過濾器可以設置從15開始，當然，從1開始也是沒有問題的；

當設置了CAN過濾器，表示只能接收指定ID的數據，其他ID發送過來的數據，不再觸發CAN中斷，可以進一步提高系統的穩定性。當CAN總線上數據比較多的時候，是很有必要的。

具體配置如下：

CAN_SlaveStartBank(15); // can2篩選器組從15開始 

CAN_FilterInitStructure.CAN_FilterNumber=15; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

//表示只能接收接收方ID為0x11，發送方ID為0x14的數據，具體看通信協議

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1114; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

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如果要設置多個過濾器，繼續配置如下：

CAN_FilterInitStructure.CAN_FilterNumber=16; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1113; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

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以此類推。

3. 單獨使用CAN2的時候必須開啟先CAN1的時鐘，否則收不到數據；

CAN完整的初始化代碼（注意F105系列的CAN2時鐘使能部分）：

//CAN模式初始化

//參數 tsjw ：重新同步跳躍時間單元.范圍:CAN_SJW_1tq~ CAN_SJW_4tq

//參數 tbs2 ：時間段2的時間單元.   范圍:CAN_BS2_1tq~CAN_BS2_8tq;

//參數 tbs1 ：時間段1的時間單元.   范圍:CAN_BS1_1tq ~CAN_BS1_16tq

//參數 brp ;波特率分頻器.范圍:1~1024;  tq=(brp)*tpclk1

//波特率=Fpclk1/((tbs1+1+tbs2+1+1)*brp);

//示例：Fpclk1的時鐘在初始化的時候設置為36M,如果設置 CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,4,CAN_Mode_LoopBack);

//則波特率為:(pclk1/((tsjw+tbs2+tbs1)*brp)) = 36Mhz/18/4 = 500Kbits

//參數 mode ：模式設置： mode:CAN_Mode_Normal,普通模式;CAN_Mode_LoopBack,回環模式; 

//CAN普通模式初始化, 波特率500Kbps 

//返回值：0,初始化OK;

//    其他,初始化失敗;

//這里我使用正常模式；CAN_Mode_Init(CAN_SJW_1tq,CAN_BS1_4tq,CAN_BS2_7tq,6,CAN_Mode_Normal);//正常模式

u8 CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode)

{

GPIO_InitTypeDef GPIO_InitStructure; //聲明結構體

CAN_InitTypeDef        CAN_InitStructure;

CAN_FilterInitTypeDef  CAN_FilterInitStructure;

NVIC_InitTypeDef  NVIC_InitStructure;//CAN接收RX0中斷使能

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);//使能PORTB時鐘                      

RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE); //新增 注意

RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN2, ENABLE);//使能CAN2時鐘  

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //復用推挽輸出

GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化IO

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;

//  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉輸入  

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; 

  GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化IO

//CAN單元設置

  CAN_InitStructure.CAN_TTCM = DISABLE;//禁止時間觸發通信模式

CAN_InitStructure.CAN_ABOM = ENABLE; /* 自動離線禁止，自動離線：一旦硬件監控到128次11個隱性位，就自動退出離線狀態。在這里要軟件設定后才能退出 */

//  CAN_InitStructure.CAN_ABOM = DISABLE;//軟件對CAN_MCR寄存器的INRQ位進行置1后清0后，一旦硬件檢測到128次11位連續的隱形位，就退出離線狀態(軟件自動離線管理)

  CAN_InitStructure.CAN_AWUM = DISABLE;//睡眠模式通過軟件喚醒(清除CAN->MCR的SLEEP位)???

  CAN_InitStructure.CAN_NART = DISABLE; /* 報文重傳, 如果錯誤一直傳到成功止，否則只傳一次 */

// CAN_InitStructure.CAN_NART = ENABLE;//禁止報文自動傳送 

  CAN_InitStructure.CAN_RFLM = DISABLE;//報文不鎖定,新的覆蓋舊的  

CAN_InitStructure.CAN_TXFP = ENABLE;  /* 發送優先級  0---由標識符決定  1---由發送請求順序決定 */

// CAN_InitStructure.CAN_TXFP = DISABLE;//發生FIFO的優先級由報文的標識符決定

  CAN_InitStructure.CAN_Mode = mode;//模式設置： mode:CAN_Mode_Normal,普通模式;CAN_Mode_LoopBack,回環模式; 

  //設置波特率

  CAN_InitStructure.CAN_SJW = tsjw;//重新同步跳躍寬度(Tsjw)為tsjw+1個時間單位  CAN_SJW_1tq  CAN_SJW_2tq CAN_SJW_3tq CAN_SJW_4tq

  CAN_InitStructure.CAN_BS1 = tbs1;//Tbs1=tbs1+1個時間單位CAN_BS1_1tq ~CAN_BS1_16tq

  CAN_InitStructure.CAN_BS2 = tbs2;//Tbs2=tbs2+1個時間單位CAN_BS2_1tq ~ CAN_BS2_8tq

//(pclk1/((1+8+9)*4)) = 36Mhz/18/4 = 500Kbits

//(pclk1/((1+4+7)*6)) = 36Mhz/18/4 = 500Kbits

  CAN_InitStructure.CAN_Prescaler = brp; 

  CAN_Init(CAN2, &CAN_InitStructure);

#if 1

//待優化

CAN_SlaveStartBank(15); // can2篩選器組從15開始 

CAN_FilterInitStructure.CAN_FilterNumber=15; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1114; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

CAN_FilterInitStructure.CAN_FilterNumber=16; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1113; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

CAN_FilterInitStructure.CAN_FilterNumber=17; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1115; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

CAN_FilterInitStructure.CAN_FilterNumber=18; 

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; 

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; 

CAN_FilterInitStructure.CAN_FilterIdHigh=0x1116; 

CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff; 

CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; 

CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0; 

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; 

CAN_FilterInit(&CAN_FilterInitStructure);

#endif

CAN_ITConfig(CAN2,CAN_IT_FMP0,ENABLE); //FIFO0消息掛號中斷允許.     

NVIC_InitStructure.NVIC_IRQChannel = CAN2_RX0_IRQn;    //優先級配置，比較特殊 USB_LP_CAN1_RX0_IRQn

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 5;     // 主優先級為1

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;            // 次優先級為0

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;/* 掛號中斷, 進入中斷后讀fifo的報文函數釋放報文清中斷標志 */

NVIC_Init(&NVIC_InitStructure);

}