Re: [avr-gcc-list] sqrt problems

[Russell Shaw]

Jack Valmadre wrote:
> Hi,
>
> I'm going to write a program that uses the sqrt() function to work out the 
> hypotenuse of a right angled triangle.  I'm testing the function using this 
> program on a 2313, but all the pins on PORTB go low.
>
> #include <avr/io.h>
> #include <math.h>
>
> int main(void) {
>  DDRB = 0xFF;
>  PORTB = sqrt(9);
>  return 0;
> }
>
> How can I fix this?

You might see the answer on the pins for ~0.1us. Try:

#include <avr/io.h>
#include <math.h>

int main(void) {
 DDRB = 0xFF;
 PORTB = sqrt(9);
 while(1){};
}