bale_counter.js

var bleno = require('bleno');

var SERVICE_UUID = 'b1a6752152eb4d36e13e357d7c225466';
var CHAR_UUID = '4b842c60ddd611e38b680800200c9a66';

bleno.on('stateChange', function(state) {
    console.log('on -> stateChange: ' + state);
    if (state === 'poweredOn') {
        bleno.startAdvertising('BaleCounter',[SERVICE_UUID]);
    } else {
        bleno.stopAdvertising();
    }
});

var value = 0;
var prev;

// Changing value here
setInterval(function() {
      //  test = value + " Bales";
        console.log(value);
        prev = value;
        value++;


}, 1000);

// changing value

bleno.on('advertisingStart', function(error) {
    console.log('on -> advertisingStart: ' + (error ? 'error ' + error : 'success'));
    if (!error) {
      console.log("set services");
        bleno.setServices([
            new bleno.PrimaryService({
                uuid : SERVICE_UUID,
                characteristics : [
                  new bleno.Characteristic({
                      uuid : CHAR_UUID,
                      properties : ['notify'],
                      onSubscribe : function(maxValueSize, updateValueCallback) {
                      // check on interval if the value changed
                        setInterval(function() {
                              if(value != prev){
                                console.log("doing it");
                                prev = value;
                                // Sending a buffer with the value and a string attached
                                // to anyone listening to broadcast
                                updateValueCallback(new Buffer(value + " bales"));
                              }
                        }, 900);
                      // close interval
                      }
                  })

                ]
            })
        ]);
    }
});