from machine import Pin

zaehler = 0
flag = False

#------------------------
def isrUP(pin):
    global zaehler, flag
    zaehler += 1
    flag = True

#------------------------
# 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