STM32F4 - can bus Id filters configuration

[alessandro2]

Posted on January 26, 2016 at 12:04

Hello everyone, I'm working with STM32F415RGT6. I need to setup the can filtering so as to get all messages which source address (I need to work with extended IDs) is different from a given one, discarded (by hardware). I'm trying to do that using the CAN_FilterConfTypeDef structure. I've had a look at the documentation (API documentation and MCU user manual), but I don't understand how the incoming message filtering works. For instance, let's suppose I need to receive messages which source address is 0x33. How should I configure the FilterIdHigh, FilterIdLow, FilterMaskIdHigh, and FilterMaskIdLow fields of the CAN_FilterConfTypeDef structure? A broader explanation of how the filtering works would also be appreciated. Many thanks in advance.

#stm32f4 #id-filters #can

[Tesla DeLorean]

Posted on January 27, 2016 at 01:19

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[Tesla DeLorean]

Posted on January 27, 2016 at 01:48

/* CAN filter init */
CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;
CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;
CAN_FilterInitStructure.CAN_FilterIdHigh = (0x033 << 5); // ID 11-bit in top bits
CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0xFFE0;// ID 11-bit in top bits, mask for comparison
CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
// if ((bitstream & CAN_FilterMaskId) == CAN_FilterId)

[alessandro2]

Posted on February 01, 2016 at 15:36Many thanks for your clear example!! I managed to get things up and running!

[gkema]

Is HAL_CAN_ERROR_PARAM about this configuration?

[Tesla DeLorean]

Probably not, but you have the library source, and can breakpoint or step that to understand what it is objecting too.

[Tesla DeLorean]

https://community.st.com/s/question/0D50X00009XkhRbSAJ/stm32-can-acceptance-mask

https://community.st.com/s/question/0D50X00009XkfSlSAJ/can-filters

https://community.st.com/s/question/0D50X00009XkfTxSAJ/stm32-can-networking-demo-filter-to-accept-everything

People were hired and tasked with fixing this mess...