CraneTank - node.js server

console.log('Loading HTTP module...'); var http = require('http');
console.log('Loading File System module...'); var fs = require('fs');
console.log('Loading NXT Bluetooth module...'); var Nxt = require('mindstorms_bluetooth').Nxt;
console.log('Loading WebSocket module...'); var WebSocketServer = require('ws').Server;
console.log('Loading Child Process module...'); var child_process = require('child_process');
console.log('All modules loaded');




var mainport = 8082;

var tank, crane;

console.log('Connecting to NXT devices...');



function closeProcess() {
    tank && tank.stop_program();
    crane && crane.stop_program();
    setTimeout(function () {
        //rfcomm.kill('SIGINT');
        process.exit(0);
    }, 100); // Wait for the NXT to stop the program
};
process.on('SIGINT', closeProcess);



tank = new Nxt('/dev/rfcomm0');
crane = new Nxt('/dev/rfcomm1');

setTimeout(function () {
    console.log("Starting programs...");
    tank.start_program("tank.rxe");
    crane.start_program("crane.rxe");
}, 8000);



tank.register_callback('messagewrite', function (data) {
    // Got a write callback
});
tank.register_callback('messageread', function (data) {
    var message = data.slice(5, 4+data[4]);
    //console.log("GOT MESSAGE", message.toString().split(","));
    broadcast(JSON.stringify({
        sensorvalues: message.toString().split(","),
        robotId: 0
    }));
});
tank.register_callback('getbatterylevel', function (data) {
    broadcast(JSON.stringify({
        batterylevel: data.readUInt16LE(3)/1000,
        robotId: 0
    }));
});

crane.register_callback('messagewrite', function (data) {
    // Got a write callback
});
crane.register_callback('messageread', function (data) {
    var message = data.slice(5, 4+data[4]);
    //console.log("GOT MESSAGE", message.toString().split(","));
    broadcast(JSON.stringify({
        sensorvalues: message.toString().split(",")
    }));
});
crane.register_callback('getbatterylevel', function (data) {
    broadcast(JSON.stringify({
        batterylevel: data.readUInt16LE(3)/1000,
        robotId: 1
    }));
});


setInterval(function () {

    tank.message_read(0);
    //crane.message_read(0);

}, 50);

setInterval(function () {
    tank.get_battery_level();
    crane.get_battery_level();
}, 2000);
tank.get_battery_level();
crane.get_battery_level();


var httpserv = http.createServer(function (req, res) {
    switch(req.url) {
        case '/':
            fs.readFile('remote.html', 'utf8', function (err, data) {
                res.writeHead(200, {'content-type': 'text/html'});
                res.end(data);
            });
            break;
        default:
            res.writeHead(404);
            res.end("Greetings programs.\n\n - C.L.U.");
            break;
    }
});
httpserv.listen(mainport, function () {
    console.log("Remote webserver is up on port "+mainport);
});




var wss = new WebSocketServer({
    server: httpserv
});

var sockets = [];
var lastSentAction = "";

var broadcast = function (text) {
    for(var i=0; i < sockets.length; i+=1) {
        if (sockets[i].readyState === 1) {
            sockets[i].send(text);
        }

    }
};

wss.on('connection', function (ws) {

    var remoteAddress = ws._socket.remoteAddress;
    console.log(remoteAddress+" joined");
    sockets.push(ws);

    ws.on('message', function (message) {
        var data = JSON.parse(message);

        var inbox = data[0];
        var action = data[1];
        var robotId = data[2];
        if (action !== lastSentAction) {
            lastSentAction = action;
            var robot = robotId === 0 ? tank : crane;
            robot.message_write(inbox, new Buffer(action));
            console.log(remoteAddress, action, robotId);
        }


    });

    ws.on('close', function (reasonCode, reasonText) {
        tank.message_write(0, new Buffer("TankStop"));
        crane.message_write(0, new Buffer("TurnStop"));
        crane.message_write(0, new Buffer("TiltStop"));
        crane.message_write(0, new Buffer("ClawStop"));

        console.log(remoteAddress+" left");
        var index = sockets.indexOf(ws);

        sockets.splice(index, 1);
    });

    ws.on('error', function () {
        console.log(remoteAddress+" got error");
        var index = sockets.indexOf(ws);

        sockets.splice(index, 1);
    });
});