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Microcontroller Programming » #define BUT_UP PORTB5

June 16, 2010
by n3ueaEMTP
n3ueaEMTP's Avatar

Quick Question & I think I know the answer but I want to make sure. Does #define BUT_UP PORTB5 mean that I can use BUT_UP in place of PB5 in if statements? For Example, when using the #define statement is:

if (PINB & ((1<<BUT_UP) == 0)

the same as

if (PINB & ((1<<PB5) == 0)

Thanks in advance for an help.

Chris B. n3ueaEMTP

June 16, 2010
by hevans
(NerdKits Staff)

hevans's Avatar

Hi Chris,

I think the answer to your question is yes. The #define is a preprocessor directive. Which means that if I do

#define FOO bar

It will take your C code and replace all occurrences of FOO in your code with bar, literally without interpreting either FOO or bar. Your example is not quite right because you said #define BUT_UP PORTB5, but I think you meant #define BUT_UP PB5, which would be correct.


June 16, 2010
by n3ueaEMTP
n3ueaEMTP's Avatar

Humberto, thanks for the information. I "borrowed" that code from the internet for a project. I decided to repalce the BUT_UP with PC5. That's what is in the NK guidebook so I just stuck with what I know.

Thanks for the response!

Chris B

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