Implementing the Watchdog Timer

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7479

robinaspey,

We are afraid because your issue is out of our support.

To use watchdog on your way you should take a look into microcontroller Atmega 1281 which is used by Waspmote, to see which registers are involved and how can they be managed. You can find lots of documentation if you google a bit.

Sorry for this inconvenience.

Regards.

yoshi_jd · **Joined:** Mon Jul 11, 2011 3:15 am **Posts:** 78

Hi Robin,

How did you manage? I'm sorry, I've moved on to new projects since so I haven't checked back here in a while.

Sambo · **Joined:** Sat Jun 30, 2012 5:41 pm **Posts:** 2

Hi yoshi_jd,

I am also interested in how you implemented the hardware WDT.

Would you email me the information, please?

Thanks in advance.

Sam
email: sb at envirosir.com

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7479

Dear Sambo,

as we said on other post, implementing a watchdog like the one you or robinaspey are trying to do is risky and you could damage Waspmote:
viewtopic.php?f=17&t=9440

Please do NOT operate in such low level, you could damage your Waspmotes.

We are concerned that other users could copy and paste your codes and damage their Waspmotes too. Please be careful with this.

Best regards

stekes · **Joined:** Thu Sep 20, 2012 5:14 pm **Posts:** 30

I would also be interested in the Watchdog implementation that is mentioned

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7479

Hi stekes,

if you take a look at this thread we don't advise the use of a watchdog to reset the mote owing to incompatibilities with the sleep modes, be very careful if you decide to implement it.

Regards.

robinaspey · **Joined:** Mon Oct 03, 2011 5:17 pm **Posts:** 83

Hi,
to use an external watchdog I used the ADM706P, this is connected to the reset
pin of the programmer header (just below the CPU). The WDI feed to this is taken from
the left hand side 0.1" connector block via Digital IO line 8.

Works perfectly. The hardware is mounted on a small daughter board that also
serves as a serial input via a MAX3232CPE which connects to our GPS.

So long as there is a pulse to this within 1.6 seconds the watchdog stays inactive,
however if the software locks up or there is degradation in performance due to
a stack overflow then all is recovered quickly.

I should add that this is only necessary using the waspmote with an XBee radio in
router mode where high throughput can cause a stack overflow. In end device mode
it is not good as it prevents the waspmote from hibernbating.

In our case we needed to use routers due to the 1.2s packet buffering delay for
end devices.

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7479

Thanks for sharing your application Robin.

Regards