Smart Parking System

Hardware components:
	Raspberry Pi 3 Model B	×	1
	Arduino Mega 2560 & Genuino Mega 2560	×	1
	HC-SR04	×	3
Software apps and online services:
	Samsung IoT ARTIK Cloud for IoT
	Google Maps
	Arduino IDE

STORY

H) Take a look to Device Fields and again click to NEXT:ACTIVE MANIFEST.

I) Congratulation! you successfully created your first device. Now you have to connect the device to Artik cloud. So, let’s do it.

J) Go to MY ARTIK CLOUD from right top corner.

K) Click on MY ARTIK CLOUD and select DEVICES.

L) Click to +Add another device.

M) Type the name of the device you just created and click on it.

N) Click on CONNECT DEVICE… button.

O) Your device is connected to the CLOUD.

P) Click on it. Generate Token, Note down your DEVICE ID and DEVICE TOKEN. These will be required latter every time you want to connect to your device from physical devices, web apps or android apps.

Step 2: Making rule in Artik Cloud

In this step we will make a rule where we set some conditions according to which Artik cloud will generate an action when the condition meets and the devices and applications subscribed to the action receive a message instantly.

A) Select RULES from the MY ARTIK CLOUD menu and Click on NEW RULE

B) From IF selection box select a data field for a device and set a value and condition. Then select an action for a specific device from THEN field. You can set a constant parameter value or can select a value from another device data. To define a data field from another device click on download icon shown in red box.

C) Select a device from the drop-down and then select data field.

D) Then click on SAVE RULE.

Step 3. Preparing Arduino

The main work of the Arduino in my project is to collect data from sensors connected to parking stations and to send the data to Raspberry pi using serial port. Here i used Arduino Mega is implemented for one parking stations. we can connect more Arduino boards for different Parking Stations. Here I used ultrasonic sensors and can be used in any location.

For ultrasonic sensors Arduino digital pins were used. Arduino sketch Ultra sonic sensors are attached. Upload appropriate sketch to your Arduino board .

Details about ultrasonic sensor can be found here.

Step 4: Connecting the Sensors

For connecting all the sensors to Arduino please see the schematic section.

Step 5: Preparing Raspberry Pi

I am assuming that, you have some previous experience in working with Raspberry pi. Lots of beginners tutorials are available in the Internet.

Let’s start our work with raspberry pi. Raspberry pi is working as a WebSocket client and communicates with Artik cloud using WebSocket protocol. I used Node.js for programming. Unlike Python Node is not preinstalled on Raspberry Pi.

A). Install Node and npm on Raspberry pi using following commands in terminal.

sudo apt-get update
sudo apt-get install nodejs npm

B). Install WebSocket client ws to raspberry pi

npm install --save ws

C). Install serialport to raspberry pi

npm install serialport

If you successfully completed all three steps then your pi is ready to communicate with Arduino using serial port and Artik cloud using websocket. As I said earlier two raspberry pis are required for two parking station. So, download the source code for the this from the Github . You can use ftp client like FileZilla to upload the code on raspberry pi. Don’t forget to change DEVICE ID & DEVICE TOKEN in the source code.

D) After uploading the code on raspberry pi run the code by typing the following command into terminal window.

sudo node staff-parking.js

Step 6. Developing Web Application

For developing web application HTML and JavaScript was used. For communicating with Artik cloud here I again used WebSocket protocol. For integrating Map in my application I used Google Map API.

Download the web-app folder from my Github and modify the DEVICE ID and DEVICE TOKEN with your own device id and token. Use ID of the device which generate the action on new data received (edison in my case). Open the websocket.html using a web browser and enjoy. See the demo video..

Schematics

Code

//staff parking data transfer
var webSocketUrl = "wss://api.artik.cloud/v1.1/websocket?ack=true";
var device_id = "Your Device id"; // staff  parking DEVICE ID
var device_token = "Your Device Token"; //staff parking DEVICE TOKEN
// require websocket module to connect 
// execute following two commands to your pi's terminal
// sudo apt-get update
// npm install websocket
var WebSocket = require('ws');
var isWebSocketReady = false;
var data="";
var ws = null;
// require serialport module to raspberry pi 
// execute following command to terminal
// npm install serialport
var serialport = require("serialport");
var SerialPort = serialport.SerialPort;
var sp = new SerialPort("/dev/ttyACM0", { //for serial communication with arduino 
    baudrate: 9600,  
// we are using UNO so baudrate is 9600, you might need to change according to your model
    parser: serialport.parsers.readline("\n")
});

var parking_state=0;// variable to check for parking state_gate

/**
 * Gets the current time in millis
 */
function getTimeMillis(){
    return parseInt(Date.now().toString());
}

/**
 * Create a /websocket connection and setup GPIO pin
 */
function start() {
    //Create the WebSocket connection
    isWebSocketReady = false;
    ws = new WebSocket(webSocketUrl);
	// this function invoked on successful connection
    ws.on('open', function() {
        console.log("WebSocket connection is open ....");
		// you must register for successful data transmission
		// registration is for authentication or secure data transfer
        register();
    });
    ws.on('message', function(data) {
      //this loop is called whenever the client sends some message
         handleRcvMsg(data); //data is send to the function handleRcvMsg()
    });
    ws.on('close', function() {
        console.log("WebSocket connection is closed ....");

    });      
    
}

/**
 * Sends a register message to /websocket endpoint
 */
//Client will only work when device gets registered from here
function register(){
    console.log("Registering device on the WebSocket connection");
    try{
        var registerMessage = '{"type":"register", "sdid":"'+device_id+'", "Authorization":"bearer '+device_token+'", "cid":"'+getTimeMillis()+'"}';
        console.log('Sending register message ' + registerMessage + '\n');
        ws.send(registerMessage, {mask: true});
        isWebSocketReady = true;
    }
    catch (e) {
        console.error('Failed to register messages. Error in registering message: ' + e.toString());
    }    
}


//data after receiving is sent here for processing
// in our case this function will not be used as we will not receive any action
// in raspberry pi. This is for future modification.
function handleRcvMsg(msg){
	// you have to parse the received string
    var msgObj = JSON.parse(msg);
    if (msgObj.type != "action") return; //Early return;

    var actions = msgObj.data.actions;
    var actionName = actions[0].name; 
    console.log("The received action is " + actionName);
  
    //you must know your registered actions in order to perform accordinlgy
    if (actionName.toLowerCase() == "settext") 
    { 
        // do something here after receiving 'parking_state'
		console.log('receving recognized action' + actionName);
    }
    else {
         //this loop executes if some unregistered action is received
         //so you must register every action in cloud
        console.log('Do nothing since receiving unrecognized action ' + actionName);
        return;
    }
   
}



/**
 * Send one message to ARTIK Cloud
 */
//This function is responsible for sending commands to cloud
//function sendStateToArtikCloud(parking) sends number of free parking slot to artik cloud
function sendStateToArtikCloud(parking_slot){
    try{
        ts = ', "ts": '+getTimeMillis();
        var data = {
            "parking_slot": parking_slot
            //setting the parking value from argument to our cloud variable "parking_value"

            };
        var payload = '{"sdid":"'+device_id+'"'+ts+', "data": '+JSON.stringify(data)+', "cid":"'+getTimeMillis()+'"}';
        console.log('Sending payload ' + payload + '\n');
        ws.send(payload, {mask: true});
    } catch (e) {
        console.error('Error in sending a message: ' + e.toString() +'\n');
    }    
}



function exitClosePins() {
    
        console.log('Exit and destroy all pins!');
        process.exit();
    
}


start();
//exectes every time when data is received from arduino (30 sec programmed delay from arduino)
sp.on("open", function () {
    sp.on('data', function(data) {
            console.log("Serial port received data:" + data);
            //sendStateToArtikCloud(data);//free parking slot
			var parking_slot = parseInt(data);
            sendStateToArtikCloud(parking_slot);
           
    });
});

process.on('SIGINT', exitClosePins);