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I've probably used the wrong term - I'm thinking of what I do when writing =
PLC code - so I can't find how to do this in my reference books.
This is part of a project I'm working on with a Raspberry Pi and an =
MCP23017 port expander.
I have a N/O pushbutton that I want to "latch" a value to a variable when =
it's been pressed. =C2=A0I have this function that gets called =
periodically in
a 'while True' statement:


def button():
=C2=A0 =C2=A0pushbutton =3D 0
=C2=A0 button_value =3D 0
=C2=A0 =C2=A0pushbutton=3Dbus.read_byte_data(address,GPIOB)
=C2=A0 =C2=A0if pushbutton > 0:
=C2=A0 =C2=A0 =C2=A0 =C2=A0 button_value =3D 1
=C2=A0 =C2=A0return button_value




I need button_value to become '1' when the button is pressed and to remain =
'1' until the entire program (only about 25 lines) ends with a sys.exit()


What do I use to 'latch' button_value?




Brian Grawburg
North Carolina

--=20
The truth will set you free . . .but first it will infuriate you.