Dealing with error and overload CAN frames using HAL_CAN drivers.

Eugenia Suarez · ‎2017-03-16

Posted on March 16, 2017 at 11:04

Ithink this could be a silly question, but I would like to clarify with any doubt type.

I'm working with HAL_CAN for the stm32L4. I'm developing a fw in a sw layer where I can configure CAN controller, filter banks, reset, send and receive, etc.. I'm configuring can data and remote frames format and I would like to know

if error frames and overhead frames must be also generated from user code or if it's a job for the STM32 under layers level (low level drivers)?
It's said, if my node has recived and error frame or if it has detected an error, the answer error frames from my node are they generated automatically, or must I do some code a part in order to generate an error frame?
How must my code deal with can error frames?
are these error frames keeping under HAL_CAN drivers? Does this layer some treatment of error/overload frames?

Thanks in advance.

#hal_can #stm32l4 #can #error-frames #overload #error-interrupts

Richard Lowe · ‎2017-03-21

Posted on March 21, 2017 at 11:00

Error frames are generated by the hardware. Once an error has been detected then, if your error interrupts are enabled the callback will be executed:

void HAL_CAN_ErrorCallback(CAN_HandleTypeDef *hcan)
{
 if( hcan->Instance == CAN1 )
 {
 osSemaphoreRelease(can_tx_semHandle);
 // Or do whatever you need, report, led, terminal.....
 }
}�?�?�?�?�?�?�?�?

Eugenia Suarez · ‎2017-03-22

Posted on March 22, 2017 at 15:41

Thank you Richard, this was the same way I was thinking to follow. But I also need I was understanding it correctly.

Regards.

Eugenia Suarez · ‎2017-03-23

Posted on March 23, 2017 at 09:55

Hi, Richard;

two doubts regarding the propper way of doing it, I don't know if you or someone could suggest something useful about the following questions, I hope it can be:

I was thinking about how and when to enable error and overrun interrupts.I think I should enable IT flags at first part of my code (i e at my init upper level function in user code) and keep it. But I can see how transmit_it and receive_it first enables these flags and disables them at the end of both operations (after interrupt detection), at HAL_CAN level (with hal_can macros). If I want to take control of can net errors during the rest of execution, m
ust I enable them, once again after transmit/receive_It interruptions being detected?
So, would be there, another moment in which I also must disable this error interruption flags?
UM mentions the 'overload flag' in 'silent mode', but it doesn't say anything more. I don't know (I don't see it) if has any register or flag bit regarding to the overload frame treatment. Must I don't care about detecting or sending overload frames?

Thanks in advance.