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STM32 CAN acceptance mask

Question asked by Lukasz Przenioslo on Jul 27, 2015
Latest reply on Jul 28, 2015 by Lukasz Przenioslo
Hello there,
I am trying to configure the acceptance mask of the CAN peripheral but I just cant seem to understand how does it work...

    CAN_FilterConfTypeDef sFilterConfig;
    sFilterConfig.FilterNumber = 0;
    sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
    sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
    sFilterConfig.FilterIdHigh = 0x0000;
    sFilterConfig.FilterIdLow = 0x0000;
    sFilterConfig.FilterMaskIdHigh = 0x0000;
    sFilterConfig.FilterMaskIdLow = 0x0000;
    sFilterConfig.FilterFIFOAssignment = 0;
    sFilterConfig.FilterActivation = ENABLE;
    sFilterConfig.BankNumber = 14;

I need a 32 bit mask. I was trying to  start filtering with not complicated filters like 0x01 or 0xFF that I have typed in FilterMaskIdLow but the filter doesnt work. When 0x01 is written, it accepts everything and when 0xFF is written it doesnt accept can messages with ID 0xFF. Could someone please explain me how to use this filter? I though its like this:

32 bit filter = (FilterMaskIdHigh << 16) | FilterMaskIdLow

But its not.