buttonGpio

@get:JvmName(name = "getButtonGpio")
@set:JvmName(name = "setButtonGpio")
var buttonGpio: Int
For boards without a hard wired button, this is the pin number that will be used
Boards that have more than one button can swap the function with this one. defaults to BUTTON_PIN if defined.

uint32 button_gpio = 4;