from time import sleep
from machine import Pin
from rp2 import bootsel_button

if __name-- == '__main__' :
    
    print( "Hello ...." )

    led = Pin( 25, Pin.OUT)

    while not bootsel_button() :
      led.toggle()
      sleep( 0.1 )
    pass

    print( "Bootsel button is pressed!" )
    print( "Goodbye!" )

pass