Develop Reference

TypeError: serialport.parsers.readline is not a function

I am trying to run this program in Raspberry Pi 3.
I have installed nodejs and ws on my raspberry pi.
Then I installed serial port module.
I am trying to create this project:enter link description here
I have tried to find solutions everywhere but I could not find one.
If any one knows how to solve this problem please help me.
var webSocketUrl = "wss://api.artik.cloud/v1.1/websocket?ack=true";
var device_id = "5bb3ba9304674086bee67fa507a215cf"; //DEVICE ID
var device_token = "36b278345b6d4d11abf764ae213c5c70"; //DEVICE TOKEN
var WebSocket = require('ws');
var isWebSocketReady = false;
var data="";
var ws = null;
var serialport = require("serialport");
var SerialPort = serialport.SerialPort;
var sp = new SerialPort("/dev/ttyACM0", { //for serial communication with arduino
baudrate: 9600,
// The baud rate of uno is 9600
parser: serialport.parsers.readline("\n")
});
/**
* 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);
ws.on('open', function() {
console.log("WebSocket connection is open ....");
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
function handleRcvMsg(msg){
var msgObj = JSON.parse(msg);
if (msgObj.type != "action") return; //Early return;
var actions = msgObj.data.actions;
var actionName = actions[0].name; //assume that there is only one action in actions
console.log("The received action is " + actionName);
}
/**
* Send one message to ARTIK Cloud
*/
//This function is responsible for sending commands to cloud
//function sendStateToArtikCloud(parking,temperature,water){
function sendDataToArtikCloud(pantry){
var result=pantry.split(" ");//data gets split by " " to get the values
try{
ts = ', "ts": '+getTimeMillis();
var data = {
"Garlic": result[1],
"Potato":result[2],
"Temperature":result[3],
"Chilli":result[4],
"Humidity": result[5],
"Ginger":result[6],
"Onion": result[7]
};
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 second when data is received from arduino (5sec programmed delay from arduino)
sp.on("open", function () {
sp.on('data', function(data) {
console.log("Serial port received data:" + data);
//var result=data.split(" ");//data gets split by " " to get the values
//sendStateToArtikCloud(result[0],result[2],result[1]);//parking,temperature,waterlevel
sendDataToArtikCloud(data);
});
});
process.on('SIGINT', exitClosePins);
I am getting an error on my raspberry pi
enter image description here
Suggest me a solution.

The documentation will tell you that Readline is spelled with a capital R
https://www.npmjs.com/package/serialport#module_serialport--SerialPort.parsers
parser: serialport.parsers.Readline("\n")
~

[TypeError: serialport.parsers.readline is not a function.]
If it has not been resolved yet, try this method.
var serialport = require("serialport")
var SerialPort = serialport.SerialPort;
var sp = new serialport("/dev/ttyACM0"),{
BaudRate: 9600,
parser: new serialport.parsers.Readline("\r\n")
});
I hope your problem is solved.

OnMessage event never getting called - Websockets client (javascript)

I am having trouble writing a client to establish a web socket connection. The client successfully establishes a connection but when the server sends data the OnMessage event never gets triggered. I am using OWIN Websocket Extension for my server side portion.
Server
dynamic data = fillData(value);
string sendInfo = Newtonsoft.Json.JsonConvert.SerializeObject(data);
byte[] infoBytes = System.Text.Encoding.UTF8.GetBytes(sendInfo);
await sendAsync(new ArraySegment<byte>(infoBytes), 1, false, pair.Key.callCancelled);
Client
try {
url = "wss://localhost/piwebapi/elements/E0DqD5loBNH0erqeqJodtALA2U5w0WX-5BGAupiQlq51PAUkVTVFVOSVRcU1VHQVJNQU5cU0FNUExFIEVMRU1FTlQ/attributes";
socket = new WebSocket(url);
socket.onopen = function (openEvent) {
document.getElementById("serverStatus").innerHTML =
'WebSocket Status:: Socket Open';
document.getElementById("destination").innerHTML =
url;
};
socket.onmessage = function (messageEvent) {
if (messageEvent.data instanceof Blob) {
var destinationCanvas = document.getElementById('destination');
var destinationContext = destinationCanvas.getContext('2d');
var image = new Image();
image.onload = function () {
destinationContext.clearRect(0, 0,
destinationCanvas.width, destinationCanvas.height);
destinationContext.drawImage(image, 0, 0);
}
image.src = URL.createObjectURL(messageEvent.data);
} else {
document.getElementById("serverResponse").innerHTML =
'Server Reply:: ' + messageEvent.data;
}
};
socket.onerror = function (errorEvent) {
document.getElementById("serverStatus").innerHTML =
'WebSocket Status:: Error was reported';
};
socket.onclose = function (closeEvent) {
document.getElementById("serverStatus").innerHTML =
'WebSocket Status:: Socket Closed';
};
}
catch (exception) { if (window.console) console.log(exception); }
The OnOpen and OnClose work just fine but somehow the OnMessage never gets triggered, any ideas?
Edit - Sending data from client to server works as well.

WebSockets using Fleck. WSS

I try to create simple chat application using secure layer WSS. Without wss it works. Here is my code:
FleckLog.Level = LogLevel.Info;
var allsockets = new List<IWebSocketConnection>();
var server = new WebSocketServer("wss://localhost:8181");
server.Certificate = new X509Certificate2(#"C:\Users\user\Desktop\sharpchat-master\server\Sharpchat\Certificate.pfx", "123");
server.Start(socket =>
{
socket.OnOpen = () =>
{ //See socket.ConnectionInfo.* for additional informations
Console.WriteLine(String.Empty);
Console.WriteLine("[NEW CLIENT CONNECTION]======================");
Console.WriteLine("GUID: " + socket.ConnectionInfo.Id);
Console.WriteLine("IP: " + socket.ConnectionInfo.ClientIpAddress);
Console.WriteLine("Port: " + socket.ConnectionInfo.ClientPort);
Console.WriteLine("=============================================");
Console.WriteLine(String.Empty);
allsockets.Add(socket);
};
socket.OnClose = () =>
{
Console.WriteLine(String.Empty);
Console.WriteLine("[DISCONNECTED CLIENT]=======================");
Console.WriteLine("GUID: " + socket.ConnectionInfo.Id);
Console.WriteLine("IP: " + socket.ConnectionInfo.ClientIpAddress);
Console.WriteLine("Port: " + socket.ConnectionInfo.ClientPort);
Console.WriteLine("=============================================");
Console.WriteLine(String.Empty);
allsockets.Remove(socket);
};
socket.OnMessage = (message) =>
{
//TODO: Json.Net Deserialize
Console.WriteLine("[JSON MESSAGE] " + message);
allsockets.ToList().ForEach(s => s.Send(message));
};
});
var input = Console.ReadLine();
while (input != "exit")
{
foreach (var socket in allsockets.ToList())
{
socket.Send(input);
}
input = Console.ReadLine();
}
When client connects to server there is an exception:
[Warn] Failed to Authenticate System.AggregateEx
ception: One or more errors occurred. ---> System.IO.IOException: The handshake
failed due to an unexpected packet format.
at System.Net.Security.SslState.InternalEndProcessAuthentication(LazyAsyncRes
ult lazyResult)
at System.Net.Security.SslState.EndProcessAuthentication(IAsyncResult result)
at System.Net.Security.SslStream.EndAuthenticateAsServer(IAsyncResult asyncRe
sult)
at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar,
Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchron
ization)
--- End of inner exception stack trace ---
---> (Inner Exception #0) System.IO.IOException: The handshake failed due to an
unexpected packet format.
at System.Net.Security.SslState.InternalEndProcessAuthentication(LazyAsyncRes
ult lazyResult)
at System.Net.Security.SslState.EndProcessAuthentication(IAsyncResult result)
at System.Net.Security.SslStream.EndAuthenticateAsServer(IAsyncResult asyncRe
sult)
at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar,
Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchron
ization)<---
Here is client code in JavaScript:
// Websocket Endpoint url
var URL = 'wss://localhost:8181';
var chatClient = null;
function connect () {
chatClient = new WebSocket(URL);
chatClient.onmessage = function (event) {
var messagesArea = document.getElementById("messages");
var jsonObj = JSON.parse(event.data);
var message = "<"+ jsonObj.user + "> " + jsonObj.message + "\r\n";
messagesArea.value = messagesArea.value + message;
messagesArea.scrollTop = messagesArea.scrollHeight;
};
}
function disconnect () {
chatClient.close();
}
function sendMessage() {
var user = document.getElementById("userName").value.trim();
if (user === "")
alert ("Please enter your name!");
var inputElement = document.getElementById("messageInput");
var message = inputElement.value.trim();
if (message !== "") {
var jsonObj = {"user" : user, "message" : message};
chatClient.send(JSON.stringify(jsonObj));
inputElement.value = "";
}
inputElement.focus();
}
Can anyone help me fix this problem?
Thank you very much!

Use full domain name in URL i.e. var URL = 'wss://localhost.company.com:8181';

Allow invalid certificates for resources loaded from localhost # Enable.
More Details are here

Ping with javascript and read the errors

I'm basically following the accepted answer to this question (Is it possible to ping a server from Javascript?)
Update
It seems to work as expected when the domain is 15 characters long (actually, http:// + 15, but 16 or more causes it to bomb. More details at the bottom.
The issue I'm seeing is that if you're using something that seems like a valid domain, for example http://thisisdefinitelynotarealdomainname.com, it returns an error but the code mentioned considers errors okay (because most should be). Looking at the error event, I'm not sure I see where I could get the HTTP response code (i.e., if it's a 404, consider it invalid).
Here is a jsFiddle showing the problem -- they all display "responded". If you look in the console, the invalid domain returns a 404 error, and the two valid ones (if in chrome console, not sure about the others) show that they were interpreted as an image but transferred as text/html -- is there any way to read either the 404 error, or the mime type?
var pinger = function () {
var ping = function (ip, callback) {
if (!this.inUse) {
this.status = 'unchecked';
this.inUse = true;
this.callback = callback;
this.ip = ip;
var _that = this;
this.img = new Image();
this.img.onload = function () {
_that.inUse = false;
_that.callback('responded');
};
this.img.onerror = function (e) {
if (_that.inUse) {
_that.inUse = false;
_that.callback('responded', e);
}
console.log(e);
};
this.start = new Date().getTime();
this.img.src = "http://" + ip + "/?now=" + this.start; // add the current time to work around caching
this.time = setTimeout(function () {
if (_that.inUse) {
_that.inUse = false;
_that.callback('timeout');
}
}, 1500);
}
}
return {
ping: ping
};
}();
(function () {
var output = document.getElementById('output');
var servers = [
'localhost',
'google.com',
'okthisreallydoesntmakeanysense',
'okthisreallydoe',
'thisisashortone',
'thisisabitlonger'
];
servers.forEach(function (server) {
new pinger.ping(server, function (status, e) {
output.innerHTML += server + ': ' + status + '<br />';
});
});
})();
Update
What's even more weird is that it seems to be fine up until 15 characters. I've updated the jsFiddle. See below on ones that respond how I'd expect vs ones that don't. What might cause this?
'localhost',
'google.com',
'okthisreallydoesntmakeanysense', // doesn't work
'okthisreallydoe', // works (15 characters)
'thisisashortone', // works (15 characters)
'thisisabitlonger' // doesn't work (16 characters)

This might help.
function Pinger_ping(ip, callback) {
if(!this.inUse) {
this.inUse = true;
this.callback = callback
this.ip = ip;
var _that = this;
this.img = new Image();
this.img.onload = function() {_that.good();};
this.img.onerror = function() {_that.good();};
this.start = new Date().getTime();
this.img.src = "http://" + ip;
this.timer = setTimeout(function() { _that.bad();}, 1500);
}
}
Let me know if it works

Public methods in javascript OOP

I want to make a javascript class with methods which I can call within the class as well as outside of the class. I want to make a "public" method, if you will. I want getTextAreaElement and appendTextArea to be such methods.
I've shown a snippet of best code I could come up with so far. I've also tried defining the methods as prototypes as well as within the class (this.func = ...). But that only allowed me to call the method outside (new Socket().appendTextArea("osgjr89");) but NOT within the class itself! The code snippet below shows the exact opposite implementation where I can't call the method outside of the class but can call it within.
Error:
Uncaught TypeError: Object #Socket has no method 'appendTextArea'
socket.js:
function Socket() {
var socket;
var canvas = document.getElementById('c');
var context = canvas.getContext("2d");
if (window.WebSocket) {
socket = new WebSocket("ws://localhost:9012/websocket");
socket.binaryType = 'arraybuffer';
socket.onopen = onopen;
socket.onmessage = onmessage;
socket.onerror = onerror;
socket.onclose = onclose;
} else {
alert("Your browser does not support Web Socket.");
}
function getTextAreaElement() {
return document.getElementById('responseText');
}
function appendTextArea(newData) {
var el = getTextAreaElement();
el.value = el.value + '\n' + newData + " :)";
}
function onopen(event) {
getTextAreaElement().value = "Web Socket opened!";
}
/*[...]*/
}
main.js (loads after socket.js)
$(document).ready(function() {
var s = new Socket();
s.appendTextArea("osgjr89"); // ERROR!
});
UPDATED socket.js:
function Socket() {
[...]
if (window.WebSocket) {
socket = new WebSocket("ws://localhost:9012/websocket");
socket.binaryType = 'arraybuffer';
socket.onopen = this.onopen;
socket.onmessage = this.onmessage;
socket.onerror = this.onerror;
socket.onclose = this.onclose;
} else {
alert("Your browser does not support Web Socket.");
}
this.getTextAreaElement = function() {
return document.getElementById('responseText');
}
this.appendTextArea = function(newData) {
var el = this.getTextAreaElement();
el.value = el.value + '\n' + newData + " :)";
}
this.onopen = function(event) {
this.getTextAreaElement().value = "Web Socket opened!";
}
[...]
}

All public methods must be declared as properties, not variables/functions. So, you have to change stuff like this:
function getTextAreaElement() {
return document.getElementById('responseText');
}
into
this.getTextAreaElement = function() {
return document.getElementById('responseText');
}

If you do this.func = function() {}, you can call the function inside the Constructor (Socket in your case) using this.func() as well as outside using:
var s = new Socket();
s.func();