"Wasn't online yet" message when pushing play to start the App

I have what appears to be a classic problem with Blynke – seeing a “Wasn’t online yet” message when I push play using an on/off LED switch I created using my Android phone. I searched and followed threads regarding this same problem in the Blynk.Community but I cannot seem to resolve the problem. A 5 minute job to get the App working has stretched into 5 hours we no luck.
I am trying to get digital pin 13 of my Arduino Uno to turn on an LED with the Blynke smartphone app. I set the app up as follows: Button Name: Light Up LED, Output: D13, Mode: Switch. ,LED starter/Arduino UNO/USB. I placed the token in the sketch I generated using the Blynk example browser. This code was generated as follows (Board: Arduino Uno, Connection: Serial or USB, Auth Token: the token I was sent, Example: LED Blink). I also installed the Blynke library and modified the batch file as follows:

set COMM_PORT=COM4 //<-- added this to match the com port I am using for the arduino uno
set COMM_BAUD=9600
set SERV_ADDR=blynk-cloud.com
set SERV_PORT=80

After I run the sketch the Serial Monitor repeatedly displays the token placed in the sketch.

Here is my sketch:

#include <Blynk.h>
/* Comment this out to disable prints and save space */
#define BLYNK_PRINT SwSerial

#include <SoftwareSerial.h>
SoftwareSerial SwSerial(10, 11); // RX, TX
#include <BlynkSimpleStream.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "I put my token info here.  Removed it for posting";

WidgetLED led1(V1);

BlynkTimer timer;

// V1 LED Widget is blinking
void blinkLedWidget()
  if (led1.getValue()) {
    SwSerial.println("LED on V1: off");
  } else {
    SwSerial.println("LED on V1: on");

void setup()
  // Debug console

  // Blynk will work through Serial
  // Do not read or write this serial manually in your sketch
  Blynk.begin(Serial, auth);

  timer.setInterval(1000L, blinkLedWidget);

void loop()

Any advice on trouble-shooting this issue would be very much appreciated.
Thank you!

How are you connecting your Uno to your PC?
You’ve defined two separate serial ports - the hardware serial for the USB to Blynk connection and a software serial port on pins 10 and 11 for debug. To see this debug output you’ll need a TTL to USB adapter (an FTDI Adapter) connected to Pins 10 & 11 (don’t forget to cross Tx & Rx). This will give you an additional serial port that can be selected in your Arduino IDE and will show you the debug output.

Is this what you’re doing, and if so, what does the debug output say?

Also, you don’t make any mention of the USB script that needs to be running in an open terminal session on your PC (closing the session will kill the connection). Are you running this script?

Unfortunately, you’ve chosen one of the most difficult boards to work with, as it has no built-in internet connectivity (essential for an IoT system) and it only has one built-in serial port, which makes connection to a device that will give you internet connectivity more difficult.

Maybe you should read this and re-consider your choice of board:


Hi Pete,

Thank you for your reply. It is most appreciated.

I watched may YouTube videos describing how to interface the Blynke App on my smartphone with the Arduino. All of these videos, including ones created by Blynke, seem to suggest it is an easy process using an Arduino Uno. So, I am surprised to learn from you that use of an Arduino has additional complications.

I am currently using what I think is the simplest approach to connect my Uno to my pc – via USB. I was planning, after this works, to connect with WiFi and finally using an ESP 8266.
While I am not new to building Arduino projects, this is my first go at using Blynk. So, there are things you mention that I do not quite understand. So, if we can take things one step at a time it would be most appreciated.

  1. You said I have defined two separate serial ports – a hardware serial port and a software serial port.
    I see in the code (written by Blynke) the statement: SoftwareSerial SwSerial(10, 11); // RX, TX .
    I assume this is what you mean by the software serial port. If I understand you, I need to be able to monitor the debug output from this port using something called a TTL to USB adaptor (An FTDI Adapter). If this is the case, I will order one on Amazon.

  2. Can you please tell me more about the hardware serial and where I have defined it?

  3. You also mention the USB script that needs to be running in an open terminal session on my PC. This is something, as I recall, that was not discussed in the YouTube videos I watched. Would you mind providing me a little more information about this?

Thank you and best regards,


  1. Yes, if you want to see the serial debug messages then you’ll need an FTDI adapter. However, I’d buy a NodeMCU or Wemos D1 Mini instead.

  2. The hardware serial port is how you’re connecting the Arduino to the PC to program it. You initialise the port with the Serial.begin(baudrate) command.

  3. Read this:

I think the reason why Arduino are discussed is because there are so many of them around. But as I said, it’s difficult to use them as IoT devices when they lack the internet connectivity out of the box.
As you’ll see from the topic I linked to, Arduino aren’t my favourite devices and although I have a few that I use for testing, I don’t use them for practical projects.


Hi Pete,
I want to make sure I am purchasing the correct item (NodeMCU). I found this on Amazon: HiLetgo 2pcs ESP8266 NodeMCU LUA CP2102 ESP-12E Internet WiFi Development Board Open Source Serial Wireless Module Works Great with Arduino IDE/Micropython (Pack of 2PCS). Is this what I need?
Thank you,

Yes, that’s the correct item.


Hello Pete,
I very much appreciate your willingness to give me a hand getting started with IoT. Our local community college will be offering an IoT class in September and this will give me a good opportunity to get a head start.

Mayby the Blynke community forum is not the best place to ask the following question and I certainly do not wish to offend anyone. But, since you have a lot of experience, I would like to know if you think I am doing the right thing by using Blynke to start down the IoT path? Would there be some better platform out there that I should spend my time learning to begin with?

Thank you in advance for your reply.

I’d say that Blynk is probably the best IoT tool that I’ve ever come across, because it allows you to create your own app layouts that have fantastic functionality without any skills in the Android/iOS area. Blynk also has plans to launch a web-based control panel that will mimic the app, which will add another level of functionality.

Rather than taking an IoT course, you would probably be better-off learning about C++ programming, as that’s the key to unlocking the power of ESP8266 based devices like the Arduino and NodeMCU.

It depends on your preferred learning style, but I’d suggest finding a series of YouTube C++ tutorials from someone whose style you like, and working your way through those.

What sort of things do you think you’ll use IoT for?
My personal focus is home automation, and for that I tend to use Blynk as my user interface, along with Amazon Alexa and a Touch-screen controller.


Hi Pete,
Thank you for the information.
I am a retired Civil Engineer and have done programming using FORTRAN in the old days and more recently with Visual Basic for Applications. I did the coding in C++ for my first two arduino projects and it got the job done but I certainly have a lot to learn. So I will take your advice and find a good source of study for C++.
My first Arduino project was a device that turns a portable heater in my office on and off at certain times to maintain a designated temperature. It works great.
My second Arduino project was to automatically turn on a hot water circulating system in the attic of hour home at designated times, detect leaks in our hot water heaters if they occur, monitor the external temperature, attic temperate and internal home temperature and write all this data to and SD card for future analysis. The purpose for collecting the temperature data is for a future home automation project related to climate control.
Both of these projects require wires. I would like to go wireless for future projects which lead me to Blynk.
My next project has to do with controlling the text on a bulletin board remotely using my smart phone.
So, these are the sorts of things I have in mind for the future that will use IoT.
Again Pete, thanks for the help.
Best regards,

Hi Scott,
I dabbled with FORTRAN, COBOL, BASIC and and Pascal many years ago, then did quite a bit with VB and VBA later.
I found it quite difficult getting to grips with the C++ ‘punctuation’. All those semicolons, curly brackets and exclamation marks seemed very odd to me, but after persevering with it I finally feel reasonably comfortable.

I’m not sure if you’ve seen my ongoing Home Automation thread (more of a blog really). I use Blynk with Node-Red, which runs on a Pi and data is transferred between devices using MQTT messages. A slightly different approach to most people, but you’ll find that MQTT messaging is frequently used in HA systems.


Hi Pete,
Thank you for your Home Automation thread. I will look at it soon.
Have a nice weekend.

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