import time
from machine import Pin

b1=Pin(1,Pin.IN,Pin.PULL_UP)
led=Pin(0,Pin.OUT)
on=0
while True:
    if b1.value()==0:
        if on==1:
            led.off()
            time.sleep_ms(200)
            on=0
        else:
            led.on()
            on=1
            time.sleep_ms(200)