A c class for de-bouncing a mechanical switch.

The parameters are the GPIO pin #, a flag that's true if using an internal pullup resistor, a pair of callback functions that get called when the pin goes either high or low, and a debounce delay in ms.

The initPin() command must be called first. It configures the input pin, and returns the inital state of the switch.

The readPin(int debounceDelay) command returns the current state (de-bounced), and calls the corresponding callback function whenever the state changes.

Source: https://www.mischianti.org/2021/04/26/wemos-d1-mini-high-resolution-pinout-and-specs/

Source: https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/

Source: https://forum.fritzing.org/t/esp32s-hiletgo-dev-boad-with-pinout-template/5357