Re: [avr-gcc-list] very simple program

[David Kelly]

On Oct 2, 2005, at 7:21 AM, Timothy Smith wrote:

> i'm learning the in's and out's of microcontroller programming, but  
> i've run into a really fundamental problem.  i get the following  
> error when i attempt to use _BV to shift a shit and set port b pin  
> 0 to output
>
> 4: undefined reference to `__stack'
>
> and here is my code
>
> #include <avr/io.h>
>
> int
> main(void){
>      while (1) {
>        DDRB = _BV(PB0);
>    };
> }

Yeah, well what else are you doing? What CPU? How are you specifying  
the CPU to the compiler? Who is complaining about __stack? My guess  
is that its the linker not the compiler and it has something to do  
with your CPU selection or failure to specify to both compiler and  
linker.

Also use of _BV(PB0) is discouraged as its nothing more than (1<<PB0)  
and for most the shift is actually easier to read and understand.

--
David Kelly N4HHE, address@hidden
========================================================================
Whom computers would destroy, they must first drive mad.