from machine import Pin, Timer #import the timer function

led1 = Pin(13, Pin.OUT)
led2 = Pin(16, Pin.OUT)
timer = Timer() #set timer variable

led1.toggle()

def blink(timer): #define the blink(timer) function
  led1.toggle()
  led2.toggle()


timer.init(freq=2.5, mode=Timer.PERIODIC, callback=blink) #