from machine import Pin
from utime import sleep

LCD1 = Pin(3,Pin.OUT)
LCD2 = Pin(4,Pin.OUT)
LCD3 = Pin(5,Pin.OUT)

while True:
    LCD1.on()
    LCD2.off()
    LCD3.off()
    sleep(1)
    LCD1.off()
    LCD2.on()
    LCD3.off()
    sleep(1)
    LCD1.off()
    LCD2.off()
    LCD3.on()
    sleep(1)