The Pulse class is derived from the OneShot class (https://github.com/twrackers/OneShot-library), which is itself derived from the StateMachine class (https://github.com/twrackers/StateMachine-library). A Pulse object will create a rising or falling pulse of a fixed duration on one of the GPIO pins when it is triggered. Like the OneShot class, a Pulse object is retriggerable, which means if it is triggered again before a pulse completes, the pulse timing will restart, extending the pulse.
Because a Pulse object is derived from OneShot, it can act as a watchdog timer with a GPIO pin in output mode connected to it. The Pulse library includes a WatchdogSim sketch in the examples directory. This sketch shows how the Pulse class can be used as a watchdog timer driving the Arduino's built-in LED as its output. The sketch requires the OneShot class and the StateMachine class, in addition to the Pulse class.
The Pulse library also includes a Pulse_test example sketch, which uses a Pulse object to briefly flash the built-in LED, triggered once per second by a StateMachine object. This sketch also requires the OneShot and StateMachine classes, in addition to the Pulse class.
The Pulse library requires installation of the OneShot and StateMachine libraries.
Instructions for installing the Pulse library can be found in file INSTALL.md in this repository at https://github.com/twrackers/Pulse-library/blob/main/INSTALL.md.