CAN Bus Error Management

Posted on April 17, 2015 at 13:06

Hey guys, using the STM32F4 + cube, I setup a CAN device which works good until I play around with disconnecting the CAN bus lines and reconnecting them. Doing so produces bus errors and I am not sure how to handle these errors in a recoverable way?

What I currently do (which is not working)

When the CAN Error callback occurs:

1) Disable CAN SCE 

(NVIC_DisbleIRQ(CAN2_SCE_IRQn))

2) Set CAN into silent mode

(BTR |= CAN_MODE_SILENT)

3) Disable the error flag

(IER &= ~CAN_IER_ERRIE)

4) Set a 5-second timer that is used by the RTOS to try to recover. During this 5-second timer I disable all CAN Rx/Tx handling (bypass my CAN manager task)

When the 5-second timer expires, I do this:

1) Reset silent mode

(BTR &= ~CAN_MODE_SILENT)

2) Re-enable the SCE interrupt

(NVIC_EnableIRQ(CAN2_SCE_IRQn))

3) Re-enable error flag

IER |= CAN_IER_ERRIE

The CAN bus does not recover however...Anyone have any ideas as to what else I should be doing?

Many thanks!

#can-bus