"Latching" variables in function
Grawburg
grawburg at myglnc.com
Tue Apr 8 16:09:28 EDT 2014
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. I have this function that gets called periodically in
a 'while True' statement:
def button():
pushbutton = 0
button_value = 0
pushbutton=bus.read_byte_data(address,GPIOB)
if pushbutton > 0:
button_value = 1
return 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
--
The truth will set you free . . .but first it will infuriate you.
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