CAN programming - program freezes after restart

Projects Programming
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I have a sketch which was written to allow a reverse camera to function correctly in a different year of car. It works by reading data from the HS-CAN bus via interrupt and then every 150ms sends a recalculate CAN message out on the MS-CAN bus.

This all seems to work great - except if the car has been stopped and restarted again (but not every time). at this point the code appears to freeze and requires a reset to start working again.

The problem appears to be in the interrupt of sending out the MS-CAN message - after a car restart it stops sending it out.

I can't see anything obviously wrong - but it seems to be to do with the sleep functions, because if i remove the set_sleep_mode(SLEEP_MODE_IDLE) from the receiving loop, the problem doesn't happen.

Anyone give me any ideas why and a better way of doing this?

rear camera.txt (2.51 KB)

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Why do you need sleep mode?

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Because the device is permanently connected to the vehicle, it needs to consume as little power as possible when not used.

I have another unit which does not use sleep and it has caused a flat battery when the car has been left for a couple of days.

Also I didn't write the code so I can't give a definitive answer why it was done in this way - other than my thoughts above :slight_smile:

Finally, it appears the above change doesn't stop it freezing - the only way to stop it is to remove wdt_disable() from the send routine