The ESP8266 has one of these,
HardwareTimer, which can be programmed to trigger
when a pre-programmed interval has elapsed. The callback handler is executed in an
interrupt context so is restricted on what it can do.
The timer is appropriate where accurate and short timing is required.
The API for hardware (and Software timer queues timers) is identical, implemented using a
CallbackTimer class template for best performance.
Hardware callback timer.
HardwareTimer1= CallbackTimer<Timer1Api<clkdiv, mode>>¶
Hardware Timer class template with selectable divider and interrupt mode.