from machine import Pin
import utime
import random

dataPIN  = Pin(13, Pin.OUT)
latchPIN = Pin(15, Pin.OUT)
clockPIN = Pin(14, Pin.OUT)

def shift_update(input,data,clock,latch):
  #put latch down to start data sending
  clock.value(0)
  latch.value(0)
  clock.value(1)
  
  #load data in reverse order
  for i in range(7, -1, -1):
    clock.value(0)
    data.value(int(input[i]))
    clock.value(1)

  #put latch up to store data on register
  clock.value(0)
  latch.value(1)
  clock.value(1)

# shift_update("10000100",dataPIN,clockPIN,latchPIN)

bit_string="00011000"

while True:
    shift_update(bit_string,dataPIN,clockPIN,latchPIN)
    # bit_string = str(random.randint(0, 1))+bit_string[:-1]
    utime.sleep(0.3)