pi74HC595 1.0.0

Use the 74HC595 Shift Register with a Raspberry Pi

pi74HC595

Allows for easy use of the 74HC595 Shift Register with a Raspberry Pi

Install

$ pip install stockfish

Usage

Initialize pi74HC595 class

You should install the stockfish engine in your operating system globally or specify path to binary file in class constructor

import pi74HC595

shift_register = pi74HC595()

There are some default settings:

def __init__(
        self,
        DS: int = 11,
        ST: int = 13,
        SH: int = 15,
        daisy_chain: int = 1,
        remember: bool = True,
    )

Pin Numbering

You will likely need to change the Raspberry Pi pins during initialization. This package uses gpio.BOARD (pin numbering as opposed to GPIO numbering):

shift_register = pi74HC595(7, 37, 22)

These can also be set after initialization with

shift_register.set_ds(7)
shift_register.set_sh(37)
shift_register.set_st(22)

Daisy Chaining

If you are daisy chaining multiple 74HC595s then you will can set daisy_chain during initialization.

shift_register = pi74HC595(7, 37, 22, daisy_chain = 2)

shift_register = pi74HC595(daisy_chain = 13)

# etc

This can also be done after initialization with

shift_register.set_daisy_chain(3) # Any positive int

Remembering Previous State

The default behaviour of a 74HC595 is that if a single new value is passed and the storage register is clocked, the old valuesa are "forgotten"

ie if current state is "10101010" and "1" is sent, the new state is "10000000" I built this package to fix this for my purposes, so if "1" is sent it will update to "11010101"

You can remove this functionality and keep the 74HC595 from "remembering" the past state during initialization.

shift_register = pi74HC595(7, 37, 22, daisy_chain = 2, remember = False)

shift_register = pi74HC595(remember = False)

# etc

This can also be done after initialization with

shift_register.set_remember(False) # True or False

Set Values with a List:

Will accept both Integers (1 and 0 only) as well as Boolean values (True and False)

shift_register.set_by_list([0, 1, 0, 1, 1, 1, 0, 0])
shift_register.set_by_list([False, True, False,...])

Set Values with an Integer:

This was created with the intent to send a single 1 or 0 for on or off, but can also function with a larger int by converting to binary

shift_register.set_by_int(0)
shift_register.set_by_int(1)

shift_register.set_by_int(12) #1100
shift_register.set_by_int(9999) #1111100111

Set Values with a Boolean:

Can send a single True or False for on or off.

shift_register.set_by_bool(True)
shift_register.set_by_bool(False)

Clear All Current Values:

Sets each value that is remembered to off (0)

shift_register.clear()

Get All Current Values:

Returns the current values, only when remember is set True

shift_register.get_values()

[0, 0, 0, 0, 0, 0, 0, 0]

Testing

$ python setup.py test

Credits

• Ilya Zhelyabuzhsky

License

MIT License. Please see License File for more information.