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Error when separating code into tabs (Arduino IDE)

I’m having a strange error with my code when I put it into separate tabs. It compiles and works fine when all on one tab in Arduino IDE (1.8.12) and esp8266 v2.6.3.

Here is the basic code:

//MAIN CODE
//Libraries
#include <BlynkSimpleEsp8266.h> //Blynk support
#include <ESP8266WiFi.h>   // connection to WiFi 
//
//Login credentials
//Blynk
char auth[] = ""; 
//WiFi credentials
char ssid[] = "";      
char pass[] = "";  


//BLYNK TAB
BLYNK_WRITE(V2)    
{
  if (param.asInt())
  {
    Blynk.virtualWrite(V1, "clr");  // Clear the terminal on V1
  }
}


//LOOP TAB
void loop ()
{
  Blynk.run();
}


//SETUP TAB
void setup()
{
  Serial.begin(74880);  
  
  setup_wifi(); //connect to wifi 

  Blynk.config(auth);  
  Blynk.connect(); 
}


//WIFI TAB
void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

I am separating it into the following tabs as per the functions:
MAIN
BLYNK
LOOP
SETUP
WIFI

The Blynk code does not seem to like this and throws the below error.

If I put either LOOP or SETUP code back into the MAIN tab it’s ok again.

Error message - BLYNK_WRITE(V2) line highlighted :

blynk:2:59: error: variable or field 'BlynkWidgetWrite2' declared void

 BLYNK_WRITE(V2)    

                                                           ^

blynk:2:24: error: 'BlynkReq' was not declared in this scope

 BLYNK_WRITE(V2)    

                        ^

blynk:2:71: error: expected primary-expression before 'const'

 BLYNK_WRITE(V2)    

                                                                       ^

Multiple libraries were found for "ESP8266WiFi.h"
 Used: E:\Dropbox\Arduino Wemos\sketches\libraries\ESP8266WiFi
 Not used: C:\Users\877\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.6.3\libraries\ESP8266WiFi
exit status 1
variable or field 'BlynkWidgetWrite2' declared void

Any ideas Blynkers?

I’m not an expert in using tabs in the IDE, but when I have done it I tend to keep the library includes, void setup and void loop in the @main@ tab (although it’s not called Main, it has the filename of the sketch).

If I’m declaring global variables in a different tab, or want to move my library includes into a different tab, then those tabs has to have #include entries in the main tab, like this:

// Include the tabs that contain includes and variable definitions in this order, to prevent compilation errors... 
#include "b_libraries_used.h"
#include "c_variables_1.h"
#include "d_variables_2.h"

The “b_” , “c_” and “d_” suffixes are so that I can control the sequence of the tabs, because the IDE wants to display them alphabetically.

Pete.

1 Like

Hi Pete,

Thanks for that it all makes sense. However in this case I’m not sure that is the issue, as I believe Arduino IDE just compiles the tabs in order, and each tab is a separate function. So essentially it should be the same.

I’m sure I have other projects without Blynk where it compiles fine. Unless I’m making a mistake somewhere.

If you post your 5 chunks of code I’ll try compiling them and see what I get.

Pete.

1 Like

Thanks Pete, I’m on my phone so bear with me:


//MAIN CODE
//Libraries
#include <BlynkSimpleEsp8266.h> //Blynk support
#include <ESP8266WiFi.h>   // connection to WiFi 
//
//Login credentials
//Blynk
char auth[] = ""; 
//WiFi credentials
char ssid[] = "";      
char pass[] = "";  


//BLYNK TAB
BLYNK_WRITE(V2)    
{
  if (param.asInt())
  {
    Blynk.virtualWrite(V1, "clr");  // Clear the terminal on V1
  }
}


//LOOP TAB
void loop ()
{
  Blynk.run();
}


//SETUP TAB
void setup()
{
  Serial.begin(74880);  
  
  setup_wifi(); //connect to wifi 

  Blynk.config(auth);  
  Blynk.connect(); 
}


//WIFI TAB
void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

I suspect that the errors you were getting are because you didn’t add .h on to the end of the tab names. I had the same errors when I did the same thing.
Renaming the tabs solved that issue, but then I had the issue that I thought I would, at the end of the compilation it says:

undefined reference to `setup'

Which means that it can’t find the void setup in the main code.
Adding the setup tab as an include solves this, but then when setup calls setup_wifi() it cant find that tab.

In the end, the solution is to do this:

//MAIN CODE
//Libraries
#include <BlynkSimpleEsp8266.h> //Blynk support
#include <ESP8266WiFi.h>   // connection to WiFi 


//Login credentials
//Blynk
char auth[] = ""; 
//WiFi credentials
char ssid[] = "";      
char pass[] = "";

#include "WIFI_TAB.h"
#include "SETUP_TAB.h"
#include "LOOP_TAB.h"

I still think that you’re better-off having at least your void loop() in the main tab, and if you put your void setup() in a different tab then you have to do an include for it.

Pete.

1 Like

Thanks again for your effort, it’s good to know it’s not just my setup that throws the error.

You may well be correct regarding the .h and #includes, but it doesn’t quite make sense to me why it’s not working.

If you read Robins comments over on the Arduino forum it should just concatenate the .ino files in order when compiling. So I fail to see why having them all in one tab, or seperate tabes in the same order is different.

I have taken other sketches and split them the same way into tabs, and it compiles fine. I don’t think this is a Blynk issue, so I will do some research over on the Arduino forum to save cluttering this one.

Thanks again!

Hmm I am beginning to think this might Blynk related after all.

If you try the Blynk example here it compiles fine with “setup” and “loop” in their own tabs (default .ino extensions).

But when moving “BLYNK_WRITE” to its own tab the error occurs. The same happens when using “BLYNK_READ” and “BLYNK_CONNECTED”.

I have uploaded the tabbed version here which compiles, unless you move the blynk function to its own tab.

**UPDATE: **
As long as there is at least one function containing Blynk code in the first “project name” tab, it compiles fine. Strange…

I think it’s to do with the fact that the Blynk libraries have includes to other libraries. This makes theses library functions available and visible to other pieces of code at compile time.

Pete

1 Like

Makes sense thanks Pete, it’s not important but little things like this bug me :grin:

Hope your Pi4 arrives soon!
Thanks

The postie just delivered it!

Pete.

1 Like