STM32 CAN滤波器设置 Identifier filter

只看该作者 · 2021-7-23 23:33

stm32的屏蔽滤波功能对ID是有要求的,mpc2515你可以直接写ID,但在STM32 这里ID必须进行移位处理.

只看该作者 · 2021-7-23 23:34

对照下表：

只看该作者 · 2021-7-23 23:34

Extended Id滤波器设置(已验证，只接受Receive_ID节点的数据)：

/* CAN filter init */ //设置成只能接受主节点 Extended Id：01 的数据 reference manual p557
CAN_FilterInitStructure.CAN_FilterNumber=0;
CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;
//CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdList;//###########################################
CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
CAN_FilterInitStructure.CAN_FilterIdHigh=(((u32)Receive_ID<<3)&0xFFFF0000)>>16;
CAN_FilterInitStructure.CAN_FilterIdLow=(((u32)Receive_ID<<3)|CAN_ID_EXT|CAN_RTR_DATA)&0xFFFF;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xFFFF;
CAN_FilterInitStructure.CAN_FilterMaskIdLow=0xFFFF; // 1 :must match” or 0: as “don’t care
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=0;
CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);

只看该作者 · 2021-7-23 23:35

Standard Id滤波器设置：

只看该作者 · 2021-7-23 23:36

CAN_FilterMaskId 位的含义是

Mask
Each bit of the register specifies whether the bit of the associated identifier register must
match with the corresponding bit of the expected identifier or not.
0: Don’t care, the bit is not used for the comparison
1: Must match, the bit of the incoming identifier must have the same level has specified in
the corresponding identifier register of the filter.

我们这里全部设置成1 ，也就是只接受CAN_Filter中设置的节点的数据