from machine import Pin, SPI
from time import sleep_ms, sleep_us, ticks_us

spi = SPI(1, baudrate=10_000_000, polarity=0, phase=0, bits=8, sck=10, mosi=11, miso=12)
LATCH = Pin(13, Pin.OUT)

def HC594(X):
    LATCH.value(0)
    Y = bytearray([X])
    spi.write(Y)
    LATCH.value(1)
    sleep_us(1)
    LATCH.value(0)

x = 0
while(1):
    x = (x + 1) & 0xFF
    t0 = ticks_us()
    HC594(x)
    t1 = ticks_us()
    print(t1 - t0)
    sleep_ms(10)