const express = require('express'); const app = express(); const SerialPort = require('serialport'); const server = app.listen(3000, function () { console.log('Example app listening on port 3000!'); }) const io = require('socket.io').listen(server); const port = new SerialPort('/dev/rfcomm0'); port.on('error', function(err) { console.log('Error: ', err.message); port.close(); }) port.on('close', function(err) { setTimeout(function() { port.open(); }, 2000); }); const update = data => { console.log('recieved ' + data); port.write(data, function(err) { if (err) { return console.log('Error on write: ', err.message); } console.log('message written'); }); } app.use('/', express.static('dist')) io.on('connection', socket => { socket.on('update', data => { update(data); }); });