IDE compiler code error: void function 'xyz' was not "declared in this scope."

edthewino · February 1, 2022, 1:50pm

I am experiencing a compile error when calling a void function from within another void. In this case the error generated says the called void 'xyz' was "not declared in this scope." Am I correct to think void functions do not require a declaration to call them?

This same code used within a WifiNINA EXAMPLES (ConnectWithWPA) sketch compiles without an error. The same library files are also referenced.

void setup() {
  // Initialize serial and wait for port to open:
  Serial.begin(115200);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE) {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  String fv = WiFi.firmwareVersion();
  if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
    Serial.println("Please upgrade the firmware");
  }

  // attempt to connect to WiFi network:
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to WPA SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network:
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:
    delay(5000);
  }
                                                        // you're connected now, so print out the data
    Serial.print("You're connected to the network");
        printCurrentNet();                                                       <<<<<<<<<< error
        printWifiData();                                                            <<<<<<<<<< error

}
void loop()
    {
    
    digitalWrite(LED_BUILTIN, HIGH);                  //  blinky blinky  
    delay(200);                       
    digitalWrite(LED_BUILTIN, LOW);    
    delay(300); 
                         
      if (temp_alarm == true && temp_alarm_state == false)
       {
//       if(DEBUG){Serial.println("         Alarm is True/Send message");}
        
        temp_alarm_state = true;
        
         sendToPushingBox(DEVID1);                          //Sending request to PushingBox when the is TRUE
       }
      if (temp_alarm == false && temp_alarm_state == true)             // temp alarm is OFF
       {
 //      if(DEBUG){Serial.println("           Alarm is false/No message sent");}
    
       temp_alarm_state = false;
      }
 
    //DEBUG part
    // this write the respons from PushingBox Server.
    // You should see a "200 OK"
  
    if (client.available()) {
    char c = client.read();
    if(DEBUG){Serial.print(c);}
  }
 
  // if there's no net connection, but there was one last time
  // through the loop, then stop the client:

   void sendToPushingBox(char devid[])
   {                         //Function for sending the request to PushingBox
    client.stop(); if(DEBUG){Serial.println("   connecting...");}
    if(client.connect(serverName, 80)) { 
    if(DEBUG){Serial.println("     connected");}
    if(DEBUG){Serial.println("     sendind request");}
    client.print("GET /pushingbox?devid=");
    client.print(devid);
    client.println(" HTTP/1.1");
    client.print("Host: ");
    client.println(serverName);
    client.println("User-Agent: Arduino");
    client.println();
  } 
    else { 
    if(DEBUG){Serial.println("          connection failed");} 
  } 
}  
   void printWifiData() {
                                 // print your board's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");

  
  Serial.println(ip);
  Serial.println(ip);

  // print your MAC address:
  byte mac[6];
  WiFi.macAddress(mac);
  Serial.print("MAC address: ");
  printMacAddress(mac);
}

     void printCurrentNet() {
                                      // print the SSID of the network you're attached to:
        Serial.print("SSID: ");
        Serial.println(WiFi.SSID());

                                      // print the MAC address of the router you're attached to:
        byte bssid[6];
        WiFi.BSSID(bssid);
        Serial.print("BSSID: ");
        printMacAddress(bssid);

                                        // print the received signal strength:
        long rssi = WiFi.RSSI();
        Serial.print("signal strength (RSSI):");
        Serial.println(rssi);

                                        // print the encryption type:
         byte encryption = WiFi.encryptionType();
         Serial.print("Encryption Type:");
         Serial.println(encryption, HEX);
         Serial.println();
     }

         void printMacAddress(byte mac[]) {
             for (int i = 5; i >= 0; i--) {
             if (mac[i] < 16) {
             Serial.print("0");
    }
             Serial.print(mac[i], HEX);
             if (i > 0) {
             Serial.print(":");
    }
  }
             Serial.println();
}

Error Code

******************** Error Code ********************************
/home/ed/Arduino/Uno_Wifi_Rev2_Push_Test_PushingBox_v3/Uno_Wifi_Rev2_Push_Test_PushingBox_v3.ino: In function 'void setup()':
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:56:9: error: 'printCurrentNet' was not declared in this scope
         printCurrentNet();
         ^~~~~~~~~~~~~~~
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:57:9: error: 'printWifiData' was not declared in this scope
         printWifiData();
         ^~~~~~~~~~~~~
/home/ed/Arduino/Uno_Wifi_Rev2_Push_Test_PushingBox_v3/Uno_Wifi_Rev2_Push_Test_PushingBox_v3.ino: In function 'void loop()':
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:75:10: error: 'sendToPushingBox' was not declared in this scope
          sendToPushingBox(DEVID1);                          //Sending request to PushingBox when the is TRUE
          ^~~~~~~~~~~~~~~~
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:97:4: error: a function-definition is not allowed here before '{' token
    {                         //Function for sending the request to PushingBox
    ^
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:114:25: error: a function-definition is not allowed here before '{' token
    void printWifiData() {
                         ^
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:130:29: error: a function-definition is not allowed here before '{' token
      void printCurrentNet() {
                             ^
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:153:43: error: a function-definition is not allowed here before '{' token
          void printMacAddress(byte mac[]) {
                                           ^
Uno_Wifi_Rev2_Push_Test_PushingBox_v3:164:1: error: expected '}' at end of input
 }
 ^
Using library SPI at version 1.0 in folder: /home/ed/.arduino15/packages/arduino/hardware/megaavr/1.8.7/libraries/SPI 
Using library WiFiNINA at version 1.8.13 in folder: /home/ed/Arduino/libraries/WiFiNINA 
exit status 1
'printCurrentNet' was not declared in this scope

J-M-L · February 1, 2022, 1:51pm

post the code... As a general rule, things in C++ need to be declared before you can use them.

When it comes to functions (a void does not mean anything) the IDE will try to help you and pre-declare them for you in case you define them in the wrong way.

for example in theory this is not correct in C++, function A tries to call functionB which is unknown

void functionA() {
  ...
  functionB();
  ...
} 

void functionB() {
 ....
}

so the right way to do this is to define functionB first.

void functionB() {
 ....
}

void functionA() {
  ...
  functionB();
  ...
}

but the IDE will help you and actually generate prototypes for you so the code that gets compiled looks like this

// tell the compiler those functions exist (declare them)
void functionA();
void functionB();

// now define them
void functionA() {
  ...
  functionB();
  ...
} 

void functionB() {
 ....
}

so you can write them in any order.

UKHeliBob · February 1, 2022, 1:52pm

The problem is in the code that you have not posted

My crystal ball sees a missing } or maybe an extra {, but who knows ?

edthewino · February 1, 2022, 2:03pm

code added to original post....

J-M-L · February 1, 2022, 2:06pm

as @UKHeliBob had guessed, if you indent the code you'll see that you have a {} issue (the loop() function is missing its closing brace in the right place)

edthewino · February 1, 2022, 4:32pm

thanks....rookie mistakes no doubt... lol

UKHeliBob · February 1, 2022, 4:38pm

But very common, hence my crystal ball being correct, and for some reason it is often the closing } of loop() that goes missing

edthewino · February 1, 2022, 4:40pm

Its kind of embarrassing really because I had checked that very thing. This shows me the importance of indentation with these functions as it makes seeing a missing brace much more apparent. Live and learn. I am a 65 year old newbie to all this...lol

UKHeliBob · February 1, 2022, 4:44pm

Do you ever Auto Format the code in the IDE ? Bad indentation sticks out like a sore thumb if you do, particularly if you configure it to put each { and } on its own line

edthewino · February 1, 2022, 4:58pm

Was not aware of that feature but I am now....lol
thanks for the tip...

UKHeliBob · February 1, 2022, 5:48pm

How can anyone live without Ctrl+T ?

I even do it automatically when typing in small sections of code here then wonder why a new tab has opened !

J-M-L · February 1, 2022, 5:51pm

I do !

(I use commandt )

system · July 31, 2022, 5:52pm

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IDE compiler code error: void function 'xyz' was not "declared in this scope."

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