Assign a variable to a pin or not?
Moderators: adafruit_support_bill, adafruit

Assign a variable to a pin or not?

by petespaco on Fri Feb 08, 2013 4:16 pm

How does the Arduino IDE know whether you want to simply assign a value to a variable vs assigning a name to an Arduino pin?

I want to do two things.
-Assign digital pin 5 to redLed
-Assign the value 5 to (global) myVariable1

I write:
int redLed = 5;
int myVariable1 = 5;

What happens?
Or, to put it another way, how do I differentiate between the two requirements?

Is it because the system only looks for pin assignments in the sketch area before that comes before "Void Setup()"

I have spent several hours reading tutorials and watching videos, trying to get to the bottom of this.
The people just stuff up at the top and it seems to work.

Sorry that I coulldn't figure this out on my own. I never did come up with a search string that would get me to what I am trying to ask.

Pete Stamaitis
Posts: 43
Joined: Thu Apr 19, 2012 7:53 pm
Location: west central wisconsin

Re: Assign a variable to a pin or not?

by adafruit_support_bill on Fri Feb 08, 2013 4:52 pm

"int redLed = 5" is just assigning the value 5 to a variable called redLed. It has nothing to do with an Arduino pin until you do something like:

digitalWrite(redLed, HIGH);

which is equivalent to:

digitalWrite(5, HIGH);

(only easier to understand!)

Posts: 37583
Joined: Sat Feb 07, 2009 10:11 am