import time


def timeit(function, n):
    start = time.ticks_us()
    for _ in range(n):
        function()

    return time.ticks_diff(time.ticks_us(), start)


class PPS:
    __slots__ = ("rtc", "pin")
    
    def __init__(self, rtc, pin, ntp=False):
        self.rtc = rtc
        self.pin = pin
        if ntp:
            self.ntp()
            
        self.pin.init(Pin.IN, pull=Pin.PULL_DOWN)
        self.pin.irq(self.pulse, Pin.IRQ_RISING)

    def ntp(self):
        try:
            import ntptime
            ntptime.settime()

        except ImportError:
            print("ntptime is not installed")

        except OSError:
            print("No internet connection")

    def pulse(self):
        dt = list(self.rtc.datetime())
        dt[-1] = 0
        dt[-2] += 1
        self.rtc.datetime(dt)


if __name__ == "__main__":
    from machine import Pin
    from machine import RTC
    
    pps_pin = Pin(17)
    rtc = RTC()
    pps = PPS(rtc, pps_pin, ntp=True)

    repeat = 1_000
    delay_us = timeit(pps.pulse, repeat) / repeat
    print(f"Delay of pps.pulse call: {delay_us:.0f} us.")