On my Leaf the bus seems to stop quite often, so the reset would have to operate quite often too. Perhaps increment a metric when the reset fires so we can monitor how often it is happening?

Sorry, forgot to mention: another option is to poll the bus manually if an interrupt hasn’t been received in N seconds. Check the status registers and if everything is not perfect then reset the controller.

On 15 Aug 2018, at 9:45 PM, Mark Webb-Johnson <mark@webb-johnson.net> wrote:

This was my worry for both esp32 can and mcp2515. We get an interrupt, but for some reason the status is not showing anything to do, so we return from the interrupt. Then, the status changes. Or, for a particular status we had to do something that we didn’t. The bus is locked up, and the interrupt never fires again, so we never get called. I wonder if we just fired the interrupt handler again manually, would it recover?

When this happens, do we need to power off then on the can bus, or is a ‘can canX stop’ ‘can canX start …’ sufficient?

Perhaps a general solution would be a watchdog. If the CAN bus does not receive anything for N seconds (perhaps 60), then restart the controller? We could simply protect it from restarting twice (a simple check of the counters), so worse case this would restart once 60 seconds after a bus normally went idle. Or is that too kludgy?

Regards, Mark.