alstublieft_notif.js

var upmBuzzer = require("jsupm_buzzer");
var mBuzzer = new upmBuzzer.Buzzer(3); //Buzzer for sound notification

var app = require('express')(); //Express Library
var server = require('http').Server(app); //Create HTTP instance
var io = require('socket.io')(server); //Socket.IO Library


var mraa = require('mraa');
var LCD  = require ('jsupm_i2clcd'); //LCD to display price & color notification
console.log('Current version of MRAA is', mraa.getVersion());

var touch = new mraa.Aio(0); //touch sensor for input testing
var touchValue;
var lcdMessage=" ";
var myLCD = new LCD.Jhd1313m1(6, 0x3E, 0x62);

var myLED = new mraa.Gpio(2);
myLED.dir(mraa.DIR_OUT);

var price = "20.000"; //sample price
myLCD.setColor(0,0,255);

var success = true;

loop();

function loop(){
    lcdMessage = price;
    showDisplay(myLCD, "TOTAL",price);
    
    var readTouch = touch.read();
    readTouch = Math.round(readTouch*.1);
    mBuzzer.stopSound();
    if(touchValue != readTouch){
        touchValue = readTouch;

        console.log(lcdMessage); 

        if(touchValue > 50){
            success = !success; //alternate between success and fail
            if(success){
                successNotif(mBuzzer,myLED, myLCD);
            }else{
                failNotif(mBuzzer,myLED, myLCD);
            }
            
        }
        
    }
    setTimeout(loop,100);
}

function showDisplay(LCD,msg1, msg2){
    //update text display on LCD
    LCD.clear();
    LCD.setCursor(0,1);
    LCD.write(msg1);
    LCD.setCursor(1,15 - msg2.length);
    LCD.write(msg2);
    
}

function successNotif(Buzzer, LED, LCD){
    //give notification when transaction is success
    LED.write(1);
    LCD.setColor(0,255,0);
    
    showDisplay(LCD,"SUCCESS!!", "Thank You :)");
    Buzzer.playSound(1000, 100000);
    Buzzer.playSound(2000, 200000);
    Buzzer.stopSound();
    
    LCD.setColor(0,0,255);
    LED.write(0);
}

function failNotif(Buzzer, LED, LCD){
    //give notification when transaction is failed
    LCD.setColor(255,0,0);
    showDisplay(LCD,"Transaction","ERROR :(");
    
    Buzzer.playSound(20000, 600000);
    Buzzer.stopSound();
    
    LCD.setColor(0,0,255);
    LED.write(0);
}

//listener for price input
io.on('connection', function(socket){
    console.log("come here");
    socket.on('changePrice', function(data){ //on incoming websocket message...
        price = data; //update blink interval
    });
});                   

server.listen(3000);