Example sketch can't compile

I recently downloaded Blynk and am simply trying to establish a connection between my board (Arduino UNO) and the app. I’m trying the Arduino_Serial_USB example sketch but can’t for the life of me get it to compile. I’ve tried reinstalling the libraries and my Arduino IDE. I’m including the code and error message, any help is appreciated.

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  Blynk is a platform with iOS and Android apps to control
  Arduino, Raspberry Pi and the likes over the Internet.
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  Blynk library is licensed under MIT license
  This example code is in public domain.

  =>          USB HOWTO:

  Feel free to apply it to any other example. It's simple!

/* Comment this out to disable prints and save space */
#define BLYNK_PRINT DebugSerial

/* Fill-in your Template ID (only if using Blynk.Cloud) */
//#define BLYNK_TEMPLATE_ID   "YourTemplateID"

// You could use a spare Hardware Serial on boards that have it (like Mega)
#include <SoftwareSerial.h>
SoftwareSerial DebugSerial(2, 3); // RX, TX

#include <BlynkSimpleStream.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "YourAuthToken";

void setup()
  // Debug console

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

void loop()
Arduino: 1.8.15 Hourly Build 2021/05/31 10:33 (Windows 10), Board: "Arduino Uno"

In file included from C:\Users\Alexander\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkApi.h:38:0,

                 from C:\Users\Alexander\Documents\Arduino\libraries\Blynk\src/BlynkApiArduino.h:14,

                 from C:\Users\Alexander\Documents\Arduino\libraries\Blynk\src/Adapters/BlynkSerial.h:18,

                 from C:\Users\Alexander\Documents\Arduino\libraries\Blynk\src/BlynkSimpleStream.h:18,

                 from C:\Users\Alexander\Documents\Arduino\libraries\Blynk\examples\Boards_USB_Serial\Arduino_Serial_USB\Arduino_Serial_USB.ino:38:

C:\Users\Alexander\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkConsole.h:20:10: fatal error: functional: No such file or directory

 #include <functional>


compilation terminated.

exit status 1

Error compiling for board Arduino Uno.

You’ve omitted some vital information from your post:

Add details :
• Hardware model + communication type. For example: Arduino UNO with Ethernet Shield
• Smartphone OS (iOS or Android) + version
• Blynk server or local server
• Blynk Library version

You also need to make it clear if you are using the original version of Blynk, or the new Blynk.360 and Blynk.Edgent version.


Hardware model is Arduino UNO with USB connection.
App is android version 2.27.29
Blynk library is the release version 1.0.0
Blynk server.

This information was originally omitted as i don’t believe it relates to the problem of the example sketch not compiling.

Downgrade to version 0.6.1 and try again.


1 Like

This worked, thank you.

1 Like

A classic case of “you don’t know what you don’t know”.
Always best to provide ALL of the information requested, as a bare minimum.


A post was split to a new topic: Need help migrating project to Blynk.Edgent