MicroPython driver for 74HC595 Shift Register IC work with Raspberry Pi Pico

main.py

import utime
from sr74hc595 import SR74hc595

dataPIN=8 # 74HC595 > 14 SER
latchPIN=6 # 74HC595 > 12 RCLK
clockPIN=7 # 74HC595 > 11 SRCLK
sr = SR74hc595(dataPIN, clockPIN, latchPIN, sr_size)

sr_size = 8 # 8, 16, 24...
bit = [0,0,0,0,0,0,0,0]

def fill(val: int):
    for i in range(sr_size):
        bit[i] = val

# ----------------------------------------------------------------

while True:
    for i in range(sr_size):
        fill(0)
        bit[i] = 1
        sr.shiftOut(bit) # LSBFIRST
        utime.sleep(0.5)
    utime.sleep(1)
    
    fill(0)
    for i in range(sr_size):
        bit[i] = 1
        sr.shiftOut(bit) # LSBFIRST
        utime.sleep(0.5)
    utime.sleep(1)

    for i in range(sr_size):
        fill(0)
        bit[i] = 1
        sr.shiftOut(bit, SR74hc595.MSBFIRST)
        utime.sleep(0.5)
    utime.sleep(1)
    
    fill(0)
    for i in range(sr_size):
        bit[i] = 1
        sr.shiftOut(bit, SR74hc595.MSBFIRST)
        utime.sleep(0.5)
    utime.sleep(1)

sr74hc595.py

from micropython import const
from machine import Pin

"""
MicroPython driver for 74HC595 Shift Register IC using GPIOs.
"""
class SR74hc595:
    LSBFIRST = const(0)
    MSBFIRST = const(1)

    def __init__(self, dataPin:int, clockPin:int, latchPin:int, size:int):
        self.data = Pin(dataPin, Pin.OUT) # 74HC595 > 14 SER
        self.latch = Pin(latchPin, Pin.OUT) # 74HC595 > 12 RCLK
        self.clock = Pin(clockPin, Pin.OUT) # 74HC595 > 11 SRCLK
        self.size = size

    def shiftOut(self, val:list[int], order = LSBFIRST):
        #put latch down to start data sending
        self.clock.low()
        self.latch.low()
        self.clock.high()
    
        if order == SR74hc595.LSBFIRST:
            #load data in reverse order
            for i in range(self.size-1, -1, -1):
                self.clock.low()
                self.data.value(val[i])
                self.clock.high()
        else: # MSBFIRST
            for i in range(self.size):
                self.clock.low()
                self.data.value(val[i])
                self.clock.high()


        #put latch up to store data on register
        self.clock.low()
        self.latch.high()
        self.clock.high()

example https://twitter.com/uzuki_aoba/status/1735280994490749387