Hi,

i wrote a blog post a while ago showing how to achive extra low framerates using a thread

http://www.local-guru.net/blog/2009/01/29/extra-low-framerates-in-processing

in the setup method set the sketch to noLoop()
and then call redraw from a thread every n seconds
(i use this method in a sketch whith one frame per
30 minutes)

void setup() {
 size(300,300);
 smooth();
 noLoop(); // <- turn off the processing loop

 start( 80 * 1000 ); // <- start the thread
}

void draw() {
 background( 255 );
 // draw some random circles
 for ( int i =0; i< 10; i++) {
   color c = color(random( 255 ));
   fill( c );
   stroke( c );
   int radius = int(random( 100 )+ 40);
   ellipse( random( width ), random( height ), radius, radius );    
 }  
}

void start( final int mil ) { //<- mil has to be final to be accessible in run()
  new Thread() {
  public void run() {
    while( true ) {    
       delay( mil );
       redraw();
     }
  }
}.start();
}

hmmmm, yes
but you could use something similar

remove the noloop from the setup()  method
and put your update code into the thread
instead of the redraw() method.

store the value you are looking for into a variable and access it
from the draw method

then the draw method can run at whatever framerate you like
and the update gets only triggert every 80 sec