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Watchdog Timer Module pulled HIGH or LOW ?

Posted: Fri Oct 20, 2017 11:16 am
by tfoutfou
Hi i have a question about watchdog timer module

On the QuickStart page you can read :
The input (IN) connection on the Watchdog Timer Module must be briefly pulled HIGH in order to reset the timer. You can add a simple function to your Arduino sketch which does this for you:
Ok , i understand that the INPUT pin need a pulse to reset the timer

But if for some reason the Arduino get stuck when the pin is HIGH , will the watchdog start the timer , or will it get stuck in a "RESET TIMER" state ?

Thank you

Re: Watchdog Timer Module pulled HIGH or LOW ?

Posted: Thu Mar 29, 2018 10:25 pm
by prabbit237
This has been a concern of mine as well and the only good solution I can think of is two watchdog circuits triggered by one pin. One would use an inverter before the timer so that when one sees a high pulse, the other sees a low one. No way for both to get stuck. However, then you have to figure out how to feed them both back into the one kill/reset output back to the MCU.