ChipKit CMOD watchdog & lockup

[shivensys]

Hello,

I am using a chipKIT CMOD design and can successfully run the watchdog timer code provided my Majenko.  My problem is that I occasionally get a nasty burst of electrical noise from a motor that completely freezes up the board.  The 8MHz oscillator continues to run, and it resets correctly with a power cycle.  Is there a mode that would prevent the watchdog from resetting the system?

Thanks in advance

Patrick

[D@n]

Isn't that the purpose of the watchdog?  To reset the system if it ever freezes?  Your system froze, and it reset.  This sounds like things worked.

What do you want to happen instead?

Dan

[shivensys]

Hi Dan,

My system froze but it didn't reset, which is exactly the problem.  I know the watchdog is working normally because it will reset in a while(1); loop. 

Patrick

 

[Larry Standage]

If the part is not in sleep, then the watchdog will reset the part.

That leaves the question of whether you could put the part to sleep during that time.

[shivensys]

Yes, I am able to put the part to sleep, and in this case the WDT does reboot the system when it times out.  When I take the watchdog timer code out of the system the sleep command stays asleep forever.  This is interesting because I read elsewhere that you need a special build of the bootloader to have the WDT take you out of sleep but I am using the stock CMOD bootloader.

I read elsewhere that if the bootloader was built in debug mode that there are exception traps that can cause it to hang like this, could that be the problem?  I am not sure how to determine that.

[jpeyron]

Hi Patrick,

I am not familiar with any mode that would affect the watchdog library but I would contact @majenko about the library. Your setup might require you to make a new bootloader as you mentioned earlier. 

cheers,

Jon

[shivensys]

Thanks everyone for the replies.  Hopefully I will understand this lockup better and can update the forum with the results.  From what I can tell the watchdog library is working perfectly and there is something else happening.  

Can anyone point me to the CMOD boot loader source so that I can make modifications?

Patrick

 

[jpeyron]

Hi Patrick,

Here is a link to the source code for the chipkit cmod's bootloader. Here is our resource page as well which includes the bootloader(hex file).

cheers,

Jon