underscore_debounce_api.js

//the buffer to store measures
var buffer = [];

//this is the function that calls the endpont
var saveToAPI = function(data){
   //here the logic fo calling the endpoint
};

//this is the function that handles data receiving
// it passes data from the buffer to the api, then clean the buffer
// note the _.debounce() function: it postpones the execution of 3000ms. 
// In that period, no more then one execution is allowed, that is every other call is ignored
var save = _.debounce(function(){
  saveToAPI(buffer);
  buffer = [];
}, 3000);

//this is the event from the sensor
sensor.addEvenListener('measure', save);