Measuring time

[coderatchance]

Hello all!

I would like to measure the time:

//other stuff omitted
//TIMER
unsigned long currentTime;
unsigned long startTime;

setup(){
// printing, etc omitted.

// start time
  startTime = millis();

}

loop(){

currentTime = millis();
Serial.print( myPWM() );
Serial.println();

}

byte myPWM() {

  static byte m;

  for (byte i = 0; i < 20; i++) {
    if ( (Data2 > myHT_L[i])   ) {
      m = myPWMval[i];
    }
  }
  return m;
}

Data2 is a number that may at some point go above or below the numbers that are stored in the myHT_L[].
The above code works well, however, I am not sure how to add the measurement of time?
For example, I would like only to return the number after the Data2 is above the myHT_L[i] e.g. 100ms.
I have started to put the code together, something like this,

byte myPWM() {

  static byte m;

  for (byte i = 0; i < 20; i++) {

    if ( (Data2 > myHT_L[i])  && (currentTime - startTime > 100) ) {

     m = myPWMval[i];
     startTime = currentTime;

    }
  }
  return m;
}

but it does not do the job. Wondering where I am getting it wrong?
Is the problem in the for loop, however, without time works just fine... hmm

Any ideas, help much appreciated.

Best.

[coderatchance]

Updating the code, did correct the problem, it works now, however, it does not cold the values,
I guess this could as well be sorted with another timer?
But where :)

byte myPWM_L() {

  static byte m;

  for (byte i = 0; i < 40; i++) {

    if ( (Data3 > myHT_L[i]) && (currentTimeL - startTimeL > 100)  ) {
      m = myPWMval[i];
    }
    if ( (Data3 < myHT_L[i]) ) {  
      startTimeL = currentTimeL;
    }

  }
  return m;
}