Neuroscience experiment: how to increase a variable by x on a function that is called every 30 seconds?

I am in need of programming help for a neuroscience experiment.

So I am going to be using a device that uses javascript coding. The device has EEG sensors and every 30 seconds (one epoch) it calls for NewEpochReceived function. If the condition is satisfied (isREM == true) it then runs a set of commands, including presenting lights at a specific pattern. In the example below it presents 10 x light flashes (1s on, 1 s off) at 50% light intensity.

What I would like to change is that everytime the function is called (every 30s) and condition isREM == true, the light_intensity increases by 5 (after it presents light at 50% intensity initially), until it reaches 100. I also want it to initiate some form of wait function so that after light pattern is presented there is a 60 second stop to presenting any lights. But trick is I still want the ZMax_Toast code bit to run and the loop to keep working every 30 seconds.

Really appreciate your input on this, my programmign skills are severely lacking.

    //ZMax_FlashLEDS("white", 100, 1, 5, 5, 1, 0); 
        //Parameters are color, intensity [0..100], ontime [0..255] * 100ms, offtime [0..255] * 100ms,
        //reps [0..255], vibrate [0 or 1], alternateEyes [0 or 1]


// ***********************************************************
// NewEpochReceived
// ----------------------------------------------------------
// called every epoch (30 seconds)
// ***********************************************************
    function NewEpochReceived(nEpoch, dxyz, isREM)
    {
        if (isREM == true) //enable_rem_detection must be true
        {
            ZMax_Toast("Epoch " + nEpoch + " is REM!", "#009900");
            var vibration = 0;
            var alternate_eyes = 0;
            var light_intensity = 50;
            var ontime = 10;
            var offtime = 10;
            var reps = 10;
            ZMax_FlashLEDS ("white", light_intensity, ontime, offtime, reps, vibration, alternate_eyes) 
        } 
    }