from machine import Pin
import machine
import micropython

zaehler = 0
flag = False

#------------------------
def callbackUP(arg):
    # sicher außerhalb der ISR
    global zaehler, flag
    zaehler += arg
    flag = True

#------------------------
def isrUP(pin):
    micropython.schedule(callbackUP, 1)

#------------------------
# Taste UP
tasteUP = Pin(17, Pin.IN)

# IRQ Trigger bei steigender Flanke (0 -> 1)
tasteUP.irq(trigger=Pin.IRQ_RISING, handler=isrUP)

#------------------------
# Hauptprogramm:
while True:
    if flag:
        print("Zähler:", zaehler)
        flag = False