How do I export this function without its value being undefined?

Question

I want to export the function manualStrobeTimeout with the values especified within the manualBPM_text.addEventListener("change")'s scope. Right now, the console logs the export as undefined, meaning that the value doesn't change from when the variable was declared. How would I export the function with the values declared within that scope? Keep in mind that I cannot declare the function's values outside of the event listener, as this would interfere with the set intervals.

Here's the relevant module's code:

import { strobeActive } from "./onBtn.js"; // variable to check if ON button is active/pressed

// manual bpm variables definition and event listener
var manualBPM = 0;
var manualBPM_interval = 0;

const body = document.querySelector("body");
var ranTimes = 0;

// strobe duration variable definition and event listener
var duration = 100;
const slider = document.getElementById("MM-duration-slider");
slider.addEventListener("input", function() {
    duration = slider.value;
}, false);

var manualBPM_text = document.getElementById("manual-value");
var manualStrobeTimeout;

if (strobeActive == true) {
    manualBPM_text.addEventListener("change", function() {
        clearInterval(manualStrobeTimeout); // so that old value doesn't interfere with new value

        manualBPM = manualBPM_text.value;
        manualBPM_interval = (60 / manualBPM) * 1000;

        manualStrobeTimeout = function() {
            // repeat once the interval expires
            setInterval(function() {
                // trigger strobe
                body.classList.remove("bg-black");
                body.classList.add("bg-white");

                // kill strobe once the strobe duration expires
                setTimeout(function() {
                    body.classList.remove("bg-white");
                    body.classList.add("bg-black");
                }, duration);
                
                ranTimes++;
                console.log("BPM: " + manualBPM + " (source: " + BPMvalueSource + ") | Strobe duration: " + duration + "ms | " + "Times ran: " + ranTimes);
            }, manualBPM_interval);
        }
    }, false);
}

export { manualBPM_text };
export { manualStrobeTimeout };

I want use the imported function in the following statement (on a seperate JS file):

if (BPMvalueSource == "manual") { 
            manualStrobeTimeout();
            console.log(manualStrobeTimeout()); // returns "undefined"
        } else if (BPMvalueSource == "tap") { 
            tapBPM_strobe();
        }

I have tried using window. to set the function as global, but to no avail. I have also made sure that I am importing and exporting correctly, and also tried using a dynamic import. This also did not work. Both JS files have the attribute type="module" especified.

Answer 1

1. The clearInterval was not clearing the interval.
2. The interval would not even be able to run since the wrapping function was never called
3. You cannot export non-constat values

let lastManualBPMValue;

if (strobeActive == true) {
    manualBPM_text.addEventListener("change", function() {
        lastManualBPMValue = manualBPM_text.value;
    }, false);
}

export { manualBPM_text };

let manualStrobeTimeout;
export function manualStrobe() {
    clearInterval(manualStrobeTimeout); // so that old value doesn't interfere with new value
    manualBPM_interval = (60 / lastManualBPMValue) * 1000;
    manualStrobeTimeout = setInterval(function() {
        ...
    }, manualBPM_interval);
}