The Constructor Meter(Meter, int,int) is undefined.
import meter.*;
Meter m;
void setup(){
size(500,400);
background(0,0,0);
//lets add a default meter
m = new Meter(this,25,10);// here 25,10 are x,y coords.
}
void draw(){
//give some random values to meter
int value = (int)random(0,10); //generates random values
//update the meters values
m.updateMeter(value);
//use delay to see the changes
delay(1000);
}