from machine import Pin
from time import sleep_ms

led01 = Pin(18, Pin.OUT)
led02 = Pin(19, Pin.OUT)
led03 = Pin(21, Pin.OUT)
led04 = Pin(22, Pin.OUT)
led01.off()
led02.off()
led03.off()
led04.off()
while True:
  sleep(0.5)
  led01.value(not led01.value())
  led02.value(not led02.value())
  led03.value(not led03.value())
  led04.value(not led04.value())
from machine import Pin
from time import sleep_ms

led = []
t_ms = 100

for i in range(0, 4):
 led.append(Pin(16+i, Pin.OUT))

while True:
 for i in range(0, 4):
  led[i].on()
  sleep_ms(t_ms)
  led[i].off()
  sleep_ms(t_ms)

 for i in range(2, 0, -1):
   led[i].on()
  sleep_ms(t_ms)
  led[i].off()
  sleep_ms(t_ms)