Compiling Error Message

Hey Blynk Community!

I had to reinstall my old mac and unfortunately i lost my arduino project files.
Blynk was running fine over Ethernet and Local PiServer.

Now i want to compile some sample codes but after updating ArduinoOSX and Blynk Library i alway get the error message below.

My Hardware:
• Mega2560+W5100 over Ethernet.
• Local Blynk RaspPI Server, running and connectable via app.
• newest Blynk Library, newest Arduino Build

#include <SPI.h>
#include <Ethernet.h>
#include <BlynkSimpleEthernet.h>

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

#define W5100_CS  10
#define SDCARD_CS 4

void setup()
  // Debug console

  digitalWrite(SDCARD_CS, HIGH); // Deselect the SD card

  // You can also specify server:
  //Blynk.begin(auth, "", 80);
  Blynk.begin(auth, IPAddress(000,000,000,00), 1234);

void loop()
  // You can inject your own code or combine it with other sketches.
  // Check other examples on how to communicate with Blynk. Remember
  // to avoid delay() function!


void loop()

I get the error message:
In file included from /Applications/
/Applications/ In member function ‘uint16_t DNSClient::BuildRequest(const char*)’:
/Applications/ warning: result of ‘(256 << 8)’ requires 18 bits to represent, but ‘int’ only has 16 bits [-Wshift-overflow=]
#define htons(x) ( (((x)<<8)&0xFF00) | (((x)>>8)&0xFF) )
/Applications/ note: in expansion of macro ‘htons’
Sketch uses 21348 bytes (8%) of program storage space. Maximum is 253952 bytes.
Global variables use 666 bytes (8%) of dynamic memory, leaving 7526 bytes for local variables. Maximum is 8192 bytes.

Any help much appreciatet!

Try commenting out one of the Blynk.begin(); statements. You have two.

  // You can also specify server:
  //Blynk.begin(auth, "", 80);
  Blynk.begin(auth, IPAddress(000,000,000,00), 1234);

Thanks a lot, that did it for the Error!

But now after successfully compiling and Uploading, I open the serial monitor and see that it is trying over and over To connect to the pi server. With no success.

I suspect it is the BlynSimpleEthernet.h Library. It is grayed out. I am unable to find it in the archive.
I will try to find it from github and install it manually I guess.

If you mean that in the in the Arduino IDE the library name isn’t highlighted in a colour then this is irrelevant. The colour coding simply relates to how the keywords file is structured in the library.

What exactly does your serial monitor say?


[ng to
[0] Getting IP…
[5704] IP:
___ __ __
/ _ )/ /_ _____ / /__
/ _ / / // / _ / '/
//_, /////_
__/ v0.6.1 on Arduino Mega

[5825] Connecting to
[10867] Connecting to
[15872] Connecting to
[20877] Connecting to
[25881] Connecting to that is an Air Conditioner is the PiServer with port 9443 open
BlynkiOS App is able to communicate with server but unable to connect to the Mega.