hypnolights.js

var noble = require('noble');
var serviceUuids = ['6e400001b5a3f393e0a9e50e24dcca9e']
var characteristicUuids = ['6e400002b5a3f393e0a9e50e24dcca9e']

noble.on('stateChange', function(state) {
  if (state === 'poweredOn') {
    noble.startScanning(serviceUuids, false);
  } else {
    noble.stopScanning();
  }
});

noble.on('discover', function(peripheral) {
    console.log('peripheral with ID ' + peripheral.id + ' found');
    peripheral.once('connect', function() {
    	console.log("Connected");
    	peripheral.on('servicesDiscover', function(services) {
    		var service = services[0];
    		console.log('Found service ' + service)
    		service.on('characteristicsDiscover', function(characteristics) {
    			var characteristic = characteristics[0];
    			console.log("characteristi found " + characteristics);
    			var i = 0;
    			setInterval(function() {
		            const buf = Buffer([i, 0xFF, 0xFF]);
	    			characteristic.write(buf, true);
	    			i = (i + 1) % 255
		        }, 100);
    		});
    		console.log('Discovering characteristics');
			service.discoverCharacteristics(characteristicUuids)
		});

    	peripheral.discoverServices(serviceUuids);
    });

    peripheral.connect();
    console.log();
});