How to design a simple watchdog circuit that will send a 1 sec negative pulse every 5 mins ( approximately ) to a microcontroller to reset it.
Assuming we using a RC charging circuit with a comparator, we can feed the dog by periodically dumping the charge in the capacitor via by a pin of the microcontroller.
How to make the comparator output a 1 sec pulse and then discharge the capacitor once the threshold is reached?
As comparators are cheaper than the 555, I would prefer to use the comparator.
There is no such thing as bad news.