import time
from machine import Pin

drukknopPin = 18
ledPin = 20

Controledrukknop = Pin(drukknopPin, Pin.IN, Pin.PULL_DOWN)
rodeLed = Pin(ledPin, Pin.OUT)
rodeLed.off()

teller = 0
laatste_change_ms = 0
DEBOUNCE_MS = 40  # 30..80ms is typisch ok

def interruptroutine(pin):
    global teller, laatste_change_ms

    nu = time.ticks_ms()
    if time.ticks_diff(nu, laatste_change_ms) < DEBOUNCE_MS:
        return
    laatste_change_ms = nu

    toestand = pin.value()      # 0 = los, 1 = ingedrukt (pull-down)
    rodeLed.value(toestand)     # LED volgt toestand

    if toestand == 1:           # alleen tellen bij echte "indruk"
        teller += 1
        print("ingedrukt", teller)

Controledrukknop.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=interruptroutine)

try:
    while True:
        time.sleep_ms(10)
except KeyboardInterrupt:
    rodeLed.off()