I think that confused me more I tried something like this but i am pretty sure its wrong.
#include <math.h>
unsigned long previousMillis = 0; // last time update
long interval = 2000; // interval at which to do something (milliseconds)
int led1 = 11;
int led2 = 10;
void setup()
{
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(9, OUTPUT);
pinMode(6, OUTPUT);
}
void loop(){
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval){
previousMillis = previousMillis + interval;
led1 = led1+1;
if (led1== 3){led1 = 3;} // reset pointer, say max = 3 for this example
float val = (exp(sin(millis()/2000.0*PI)) - 0.36787944)*108.0;
switch(led1){
case 0:
analogWrite(led1, val);
break;
case 1:
analogWrite(led2, val);
} // end switch
} // end time check
} // end loop