# Up Counter using interrupts
from machine import Pin

interrupt_flag=0
N = 0

pin = Pin(15,Pin.IN,Pin.PULL_UP)
def IntServe(pin):
    global interrupt_flag
    global N
    interrupt_flag=1
    N = N + 1

pin.irq(trigger=Pin.IRQ_FALLING, handler=IntServe)

while(1):
    if(interrupt_flag):
        print("N = ", N)
        interrupt_flag=0