16 bit serial to parallel GPIO interface

shift.py

#!/usr/bin/env python3
#
# Code accompanying https://www.youtube.com/watch?v=SnPh4zwQkVI
import atexit
from time import sleep
from gpiozero import DigitalOutputDevice


def _pulse(pin):
    pin.value = 1
    sleep(.001)
    pin.value = 0


class ShiftRegister(object):
    def __init__(self, width=8, ser=2, oe=3, rclk=4, sclk=17, clr=27):
        self.width = width
        self.data = DigitalOutputDevice(ser)
        self.oe = DigitalOutputDevice(oe)
        self.rclk = DigitalOutputDevice(rclk)
        self.sclk = DigitalOutputDevice(sclk)
        self.clr = DigitalOutputDevice(clr)
        self.oe.value = 0
        self.clr.value = 1

    def close(self):
        self.clear()
        self.data.close()
        self.rclk.close()
        self.sclk.close()
        self.clr.close()

    def clear(self):
        self.clr.value = 0
        sleep(.001)
        _pulse(self.rclk)
        self.clr.value = 1

    def load(self, val):
        for i in range(self.width - 1, -1, -1):
            self.data.value = (val >> i) & 1
            sleep(.005)
            _pulse(self.sclk)
        _pulse(self.rclk)


if __name__ == '__main__':
    shift = ShiftRegister(width=16)
    atexit.register(shift.close)
    print('Type any number (use 0xf and 0o7 for hexadecimal and octal input)')
    while True:
        try:
            val = input('> ')
            if val.lower() in ('quit', 'q'):
                break
            val = int(val,
                      16 if val.startswith('0x') else
                      8 if val.startswith('0o') else
                      10)
            shift.clear()
            shift.load(val)
        except EOFError:
            break
        except ValueError as e:
            print(e)