Teensy WatchDogTimer

I plan on using Teensy 3.2 in an embedded project and will need a watchdog timer to reset the system if software stops behaving itself.

This misbehavior will be defined by the processor periodically writing to a hardware pin which will keep a timer from expiring which will keep the timer from pulling the reset pin low.

i want to know if I can achieve this by using a built in timer and having its output connected to the reset pin, so that the processor periodically resets the timer or nullifies the period count periodically to prevent it from driving the reset pin low. Can this be done?

Would like some advise on trying to do this.

Hi Clem,

That should be possible. However, the simplest and most reliable method for problems such as these is to use a separate watchdog timer such as that which I’ve linked below and incorporate it into the project. Please let me know if there’s anything else that I can do for you.

Bryce
Core Electronics | Support

Hi Bryce,

Thanks for your comment.

I favor the inbuilt timer because I do not easily have access to the reset pin on the Teesny 3.2 when I use it by populating the outside row of through hole connections as a pin plug in module to a circuit board.

Using only these outside row of pins there is no access to the reset pin.

Thanks

Hi Clem,

Ah excellent, I completely understand. I’ve found another forum discussing this same content that should be applicable to solving this issue, be careful however, as there’s been discussion online about potentially bricking the Teensy when implemented incorrectly. This is likely untrue, but it’s worth being conscious of the issue.

https://forum.pjrc.com/threads/25370-Teensy-3-0-Watchdog-Timer

Also, here’s a Wordpress I found about setting this watchdog timer up on the Teensy.

If you find any solutions to your problem make sure to let us know so that we can assist other makes with these issues in the future.

Regards,
Bryce
Core Electronics | Support