Fw: [avr-gcc-list] Question about gcc preprocessing and port/pinassignments

[Royce & Sharal Pereira]

Hi,
----- Original Message -----
From: "James Washer" <address@hidden>
To: <address@hidden>
Sent: Monday, December 06, 2004 11:49 AM
Subject: [avr-gcc-list] Question about gcc preprocessing and
port/pinassignments


>
>
> I'd like to be able to say something like
>
> #define switch PB7
> setpin(PB7)
>
> and have the following code generated
>
> PORTB |= 1<<7
> What I'm hoping for is the ability to change the definition of "switch" at
any time, and have everything work
>
> For example
>
> if I change switch to PD2, the preprocessor would (auto)magically arrange
for the following code
>
> PORTD |= 1<<2
> Any ideas?
----------------------------------------------
You could do this.

#define setpin(prt,pos)    prt |= 1<<pos;

#define SWITCH      portd, 2  /*only this would be needed to be modified*/

...and in your body:-

setpin(SWITCH);
//---------------------

This would work, but there may be a more elegant way. I'll leave that to the
other list members!

Regards,
--Royce.