from machine import Pin
from time import sleep
EXTERNAL_LED_PIN1 = 8
EXTERNAL_LED_PIN2 = 9
EXTERNAL_LED_PIN3 = 10
EXTERNAL_LED_PIN4 = 11
EXTERNAL_LED_PIN5 = 12

led1 = machine.Pin(EXTERNAL_LED_PIN1, machine.Pin.OUT)
led2 = machine.Pin(EXTERNAL_LED_PIN2, machine.Pin.OUT)
led3 = machine.Pin(EXTERNAL_LED_PIN3, machine.Pin.OUT)
led4 = machine.Pin(EXTERNAL_LED_PIN4, machine.Pin.OUT)
led5 = machine.Pin(EXTERNAL_LED_PIN5, machine.Pin.OUT)

while True:
    # blink the first LED
    led1.high()
    sleep(.5)
    led1.low()

    # blink the 2nd LED
    led2.high()
    sleep(.5)
    led2.low()


    # blink the 3rd LED
    led3.high()
    sleep(.5)
    led3.low()


    # blink the 4th LED
    led4.high()
    sleep(.5)
    led4.low()