Blue Pill - CAN register descriptions

[Rrr.1]

stm32f103C8 - (The blue pill board)

Hi, Just confirming that there is no mention of the SPECIFIC registers, (and the EXACT bits), needed in order to set up interrupts for the CAN bus on the blue pill board.

(I am hard coding in C, not using CUBEMX)

[Tesla DeLorean]

The Reference Manual RM0008 should detail the NVIC, and CAN registers. The Data Sheet options specific to the part you're using

[Rrr.1]

Thank you for the reply, however:

Maybe, the easy way to ask this is,

To Enable interrupt for CAN Bus Receive, I need to use NVIC_ISERx register.

BUT..

All bits in the NVIC_ISERx register are labelled 'rs'. (Ref Manual + Programming manual)

(Datasheet does not look at register structure - its more general than the Ref Manual + Prog manual)

I dont know which of the register bits relates to the CAN RECEIVE INTERRUPT as they are all called 'rs'

[Tesla DeLorean]

There are two RX interrupts, one for each FIFO, NVIC bit 20 and 21

As I recall this F1 part the RX0 overlaps with USB_LP_IRQ (you can either use CAN or USB, as they share a FIFO RAM)

[Rrr.1]

Yes the blue pill board is old. I think that you can use CAN or USB, bot not both at the same time.

Ah, so if I set bit 20 of the NVIC_ISERx register. this will ENABLE the CAN1_RX0 interrupt for FIFO_0?

[Rrr.1]

Hi,

Can anyone confirm that below contains the correct code for ENABLING the FIFO/ CAN receive INTERRUPTs for:

(1)- CAN peripheral

(2)- NVIC - the CAN_RX0/ FIFO 0 interupt

(3)- Is the code in (3) equivalent to the code in (2)

(1) -

CAN1->IER |= CAN_IER_FMPIE1;

CAN1->IER |= CAN_IER_FMPIE0; // CAN_RX0

(2) -

NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);

NVIC_EnableIRQ(CAN1_RX1_IRQn);

NVIC_EnableIRQ(CAN1_SCE_IRQn);

(3) - Do the lines below do the same as the NVIC_EnableIRQ lines

NVIC->ICER[0] |= (NVIC_ICER_CLRENA_20 | NVIC_ICER_CLRENA_21); 

NVIC->ISER[0] |= (NVIC_ISER_SETENA_20 | NVIC_ISER_SETENA_21);

I would appreciate your help with this

Regards,

[Peter BENSCH · Accepted solution]

This thread relates to a so-called Blue Pill, which uses illegally cloned STM32F103. ST resources are only dedicated to supporting genuine ST products. We are not committed to ensuring that clones/fakes products work properly with the firmware we provide.

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