from machine import Pin
from time import sleep_ms, sleep_us

CLK = Pin(10, Pin.OUT)
DOUT = Pin(11, Pin.OUT)
LATCH = Pin(13, Pin.OUT)

def HC594(X):
    LATCH.value(0)
    CLK.value(1)
    sleep_ms(1)
    for i in range(0,8):
        if(X & (0x80 >> i)):
            DOUT.value(1)
        else:
            DOUT.value(0)
        CLK.value(0)
        sleep_ms(1)
        CLK.value(1)
        sleep_ms(1)
    LATCH.value(1)
    DOUT.value(0)
    sleep_ms(1)
    LATCH.value(0)

x = 0
while(1):
    x = (x + 1) & 0xFF
    HC594(x)
    sleep_ms(100)