I have a perfectly working script. Basically, I am polling an API every 5 seconds for myJson.Temperature and a MIDI note is played corresponding to the returned value. The values are between 0 and 16. Here is the script:

let easymidi = require("easymidi")
let output = new easymidi.Output("mindiPort", true)
let interval;
const fetch = require("node-fetch");

let sendNote = (noteValue, duration) => {
    output.send("noteon", noteValue)

    setTimeout(()=> {
        output.send("noteoff", noteValue)
    }, duration);
}

const api_url = 'https://www.placeholder_url.com?timeout=1000'
setInterval(() =>
fetch(api_url)
   .then((response) => {
      return response.json();
   })

.then((myJson) => {
      let note;
      if (myJson.temperature == 0) {
        note = 24;
      } else if (myJson.temperature == 2) {
        note = 25;
      } else if (myJson.temperature == 4) {
        note = 26;
      } else if (myJson.temperature == 6) {
        note = 27;
      } else if (myJson.temperature == 8) {
        note = 28;
      } else if (myJson.temperature == 10) {
        note = 29;
      } else if (myJson.temparature == 12) {
        note = 30;
      } else if (myJson.temperature == 14) {
        note = 31;
      } else {
        note = 32;
      }
      let noteValue = {
         note: note,
         velocity: 100,
         channel: 1
       }
       sendNote(noteValue, 500)
   
 }), 5000); // API call every 5 seconds **This will also play a (same) note every five seconds
//  if conditions are met**

How do can I get the note to only play once ie; - if a subsequent poll is done and returns the same value, that note can be ignored until a unique value is returned? I have looked at filter and onlyUnique but I am not sure how to incorporate them into the code. Thank You in advance.