server.js

var http = require('http');
var url = require('url');
var rpi433    = require('rpi-433-tristate');
// setting up the mitter
rfEmitter = rpi433.emitterTriState({
    pin: 0,                     //Send through GPIO 0 (or Physical PIN 11)
    pulseLength: 300            //Send the code with a 300 pulse length
});
//Array for State of Switches
var switchStateDict= {};

http.createServer(function (req, res) {
    var q = url.parse(req.url, true).query;
    var stat = mainController(q.sys,q.family, q.switchCode,q.onOff);
    //asked for status give success + status as plain text
    if(stat == 0 || stat == 1){
        res.writeHead(200, {'Content-Type': 'text/html'});
        var txt = stat;
    //asked for switching, give if switch exists or nor
    }else if (stat == 200) {
        res.writeHead(stat,{'Content-Type': 'text/html'});
        var txt = "switched: "+q.sys+" "+q.family+" "+q.switchCode;
    //any other gives an internal error
    }else if (stat == 404) {
        res.writeHead(stat,{'Content-Type': 'text/html'});
        var txt = "Couldn't find this Switch: "+q.sys+" "+q.family+" "+q.switchCode;
    }else {
        console.log("Error!\n received: "+q.sys+" "+q.family+" "+q.switchCode+" status: "+stat);
        res.writeHead(502, {'Content-Type': 'text/html'});
        var txt ="502 Internal Server Error!";
    }
    res.end(txt);
}).listen(8080);

//main controller
function mainController(sys, familyCode, switchCode, onOff){
    var code = "";
    var returnCode = 502;
    if(onOff == 2){
        var state = getState(familyCode,switchCode);
        // in case the node just started and doesnt know the current state of a switch
        // the default is off.
        if (state == 0 || state == 1){
            return state;
        }else {
            return 0;
        }
    }else if(onOff == 0 || onOff == 1){
        switch (sys){
            case "inter":
                code = generateIntertechnoCode(familyCode,switchCode,onOff);
                changeState(familyCode,switchCode,onOff);
                returnCode = 200;
                break;
            case "elro":
                code = generateElroCode(familyCode,switchCode,onOff);
                changeState(familyCode,switchCode,onOff);
                returnCode = 200;
                break;
            default:
            returnCode = 404;
        }
        console.log(new Date().toString() + " Sending Code " + code +" now...");
        sleep(300, function(){rfEmitter.sendCode(code);});
        return returnCode;

    }else {
        return 404;
    }
}

// receive the current state of a switch
function getState(familyCode, switchCode){
    var code = familyCode.toString()+switchCode.toString();
    var state = switchStateDict[code];
    //what if switch doesnt exist
    if(state == 1 || state == 0){
        return state;
    }else {
        return -1;
    }
}
// update the current state of a switch
function changeState(familyCode,switchCode,onOff){
    var code = familyCode.toString()+switchCode.toString();
    switchStateDict[code] = onOff;
    console.log(code+": "+switchStateDict[code]);
}

// Generate Code for Intertechno Switches for sending it via sendTriState()
function generateIntertechnoCode(familyCode, switchCode, onOff){
    var codes = ["0000", "F000", "0F00", "FF00", "00F0", "F0F0", "0FF0", "FFF0",
                 "000F", "F00F", "0F0F", "FF0F", "00FF", "F0FF", "0FFF", "FFFF"];
    var finalCode = "";
    finalCode += codes[familyCode-1];
    finalCode += codes[switchCode-1];
    finalCode += "0F";
    if (onOff == 1){
        finalCode += "FF";
    }else{
        finalCode += "F0";
    }
    //console.log("generated inter Code: "+finalCode);
    return finalCode;
}

// Generate Code for ELRO Switches for sending it via sendTriState()
function generateElroCode(familyCode, switchCode, onOff){
    var finalCode = "";
    var familyCodeArray = familyCode.toString().split("");
    //from 10101 to F0F0F
    finalCode += replaceOnes(familyCodeArray, true);
    var sn = Number(switchCode);
    var switchBinaryCode = sn.toString(2);
    switchBinaryCode = replaceOnes(switchBinaryCode,true);
    //fill up to 5 bits
    while(switchBinaryCode.length < 5){
        switchBinaryCode = "F" + switchBinaryCode;
    }
    finalCode += switchBinaryCode;
    //add bits for on/off
    if (onOff == 1){
        finalCode += "0F";
    }else{
        finalCode += "F0";
    }
    return finalCode;
}

// inverted == true 0->F, inverted == false 1
function replaceOnes(string,inverted){
    var result = "";
    for (x in string){
        if(inverted){
            if(string[x] == 1){
                result += "0";
            }else{
                result += "F";
            }
        }else{
            if(string[x] == 1){
                result += "F";
            }else{
                result += "0";
            }
        }
    }
    return result;
}

// sleep for multiple Calls by a e.g. a scene
function sleep(time, callback) {
    var stop = new Date().getTime();
    while(new Date().getTime() < stop + time) {
        ;
    }
    callback();
}