Arduino USB Project is offline in App

Hello Everyone, I am testing Blynk for my students so they can use it in a project. I have followed the instructions but the app is not connecting to the Arduino via USB I have entered the details via the Terminal on the Mac and seems to be connecting to the correct port.

Also checked logs from mobile device and found this error log:
2019/05/12 14:03:44:618 App sent net op 7101 with error: Error Domain=kACNetworkManagerErrorDomain Code=7 "Hardware is offline" UserInfo={NSLocalizedDescription=Hardware is offline, NSLocalizedFailureReason=Error}

Here is what the board is doing:
Arduino UNO without Shield
• Smartphone OS (iOS ) 12.2
• Blynk server or local server? ( How can I tell?)
• Blynk Library version VO 6.1
• Add your sketch code. :point_up:Code should be formatted as example below.

Simply paste your code between ``` If you don’t format your code, your topic can be deleted by moderators.

  Download latest Blynk library here:

  Blynk is a platform with iOS and Android apps to control
  Arduino, Raspberry Pi and the likes over the Internet.
  You can easily build graphic interfaces for all your
  projects by simply dragging and dropping widgets.

    Downloads, docs, tutorials:
    Sketch generator: 
    Blynk community:  
    Follow us:        

  Blynk library is licensed under MIT license
  This example code is in public domain.

  =>          USB HOWTO:

  You can send/receive any data using WidgetTerminal object.

  App project setup:
    Terminal widget attached to Virtual Pin V1

/* 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[] = "75f4d24ceee84765ab01df9d771994c6";

// Attach virtual serial terminal to Virtual Pin V1
WidgetTerminal terminal(V1);

// You can send commands from Terminal to your hardware. Just use
// the same Virtual Pin as your Terminal Widget

  // if you type "Marco" into Terminal Widget - it will respond: "Polo:"
  if (String("Marco") == param.asStr()) {
    terminal.println("You said: 'Marco'") ;
    terminal.println("I said: 'Polo'") ;
  } else {

    // Send it back
    terminal.print("You said:");
    terminal.write(param.getBuffer(), param.getLength());

  // Ensure everything is sent

void setup()
  // Debug console

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

  // This will print Blynk Software version to the Terminal Widget when
  // your hardware gets connected to Blynk Server
  terminal.println(F("Blynk v" BLYNK_VERSION ": Device started"));
  terminal.println(F("Type 'Marco' and get a reply, or type"));
  terminal.println(F("anything else and get it printed back."));

void loop()

If you’re trying to do this from a school/college network then it’s possible that some of the Blynk communication protocols are being blocked by a firewall.
Have you tried it from your home network?

Trying it with a PC rather than Mac may also be worth a try.

What does the SoftwareSerial debug print output show?


Thanks for your help, I checked the log via the iPhone and found this:[ quote=“sdhesketh, post:1, topic:37043”]
2019/05/12 14:03:44:618 App sent net op 7101 with error: Error Domain=kACNetworkManagerErrorDomain Code=7 “Hardware is offline” UserInfo={NSLocalizedDescription=Hardware is offline, NSLocalizedFailureReason=Error}

I am at home, we are a 1-1 Macbook school so need it to work on the Mac!

Yes, I say that error message in your first post. What you need to be seeing is what is happening at the hardware end, hence my question about the SoftwareSerial debug output.

Using a PC instead of a Mac was a suggestion to get you over your first hurdle. Once you get to the bottom of the issue then you could revert back to a Mac.


Hi Peter,

Thanks for your help,

So my next question is how do I run a software bug report?

If you mean ‘how do I view the SoftwareSerial debug output’ then the answer is to connect a TTL to USB (FTDI) adapter to the SoftwareSerial Tx/Rx pins (remembering to connect Tx on the Arduino to Rx on the FTDI) and open a serial monitor on your computer to view the results.