STM32 using CAN-BUS.

aaah yess the well documented stm32 canbus filters :D

this helped me:

//usage of can filters
 
//https://schulz-m.github.io/2017/03/23/stm32-can-id-filter/
 
//https://www.diller-technologies.de/stm32.html <-----this guy knows better

this is how i setup with no filter

void CanSETUPnoFilter(CAN_HandleTypeDef *hcan_object_reference,){
 
	canfilter.FilterActivation = CAN_FILTER_ENABLE; //CAN_FILTER_ENABLE;//CAN_FILTER_DISABLE
	canfilter.FilterBank = 0;
	canfilter.FilterFIFOAssignment = CAN_FILTER_FIFO0; //CAN_FILTER_FIFO1
	canfilter.FilterIdHigh = 0;
	canfilter.FilterIdLow = 0;
	canfilter.FilterMaskIdHigh = 0;
	canfilter.FilterMaskIdLow = 0;
	canfilter.FilterMode = CAN_FILTERMODE_IDMASK; //CAN_FILTERMODE_IDMASK;//CAN_FILTERMODE_IDLIST
	canfilter.FilterScale = CAN_FILTERSCALE_32BIT; //CAN_FILTERSCALE_32BIT
	canfilter.SlaveStartFilterBank = 0;
 
	HAL_CAN_ConfigFilter(_hcan, &canfilter);
	HAL_CAN_ActivateNotification(_hcan, CAN_IT_RX_FIFO0_MSG_PENDING); //activate interrupt for received canbus
	//enable pins of the can transceivers
	HAL_GPIO_WritePin(CAN_INH_GPIO_Port, CAN_INH_Pin, GPIO_PIN_RESET);
	HAL_GPIO_WritePin(CAN_INH_2_GPIO_Port, CAN_INH_2_Pin, GPIO_PIN_RESET);
 
	HAL_CAN_Start(_hcan); //CRANK UP THE MOTORS!! BRRREM BRRREM starts can
 
}

 this is how i setup a mask filter

void CanSETUPmaskFilter(CAN_HandleTypeDef *hcan_object_reference) {
 
	canfilter.FilterActivation = CAN_FILTER_ENABLE; //CAN_FILTER_ENABLE;//CAN_FILTER_DISABLE
	canfilter.FilterBank = 0;
	canfilter.FilterFIFOAssignment = CAN_FILTER_FIFO0; //CAN_FILTER_FIFO1
	canfilter.FilterIdHigh = ( 0x100 << 3 ) >> 16 ;
	canfilter.FilterIdLow = 0x100 << 3 | 4 ;
	canfilter.FilterMaskIdHigh = 0xFE0 << 5 ;
	canfilter.FilterMaskIdLow = 0xFFF << 5| 0x10;
	canfilter.FilterMode = CAN_FILTERMODE_IDMASK; //CAN_FILTERMODE_IDMASK;//CAN_FILTERMODE_IDLIST
	canfilter.FilterScale = CAN_FILTERSCALE_16BIT; //CAN_FILTERSCALE_32BIT
	canfilter.SlaveStartFilterBank = 0;
 
	HAL_CAN_ConfigFilter(_hcan, &canfilter);
	HAL_CAN_ActivateNotification(_hcan, CAN_IT_RX_FIFO0_MSG_PENDING); //activate interrupt for received canbus
	HAL_CAN_Start(_hcan); //CRANK UP THE MOTORS!! BRRREM BRRREM starts can
 
}