Error Message: error: expected unqualified-id before numeric constant

Projects Programming
1

Code:

#include <SevenSeg.h>

SevenSeg disp(11,7,3,5,6,10,2);

const int numOfDigits=4;
int digitPins[numOfDigits]={12,9,8,13};

void setup() {
  
  disp.setDigitPins(numOfDigits, digitPins);

}  

void loop() {

    disp.write(13.28);

}

Error Message:

In file included from C:\Users\stier\AppData\Local\Arduino15\packages\arduino\hardware\mbed_nano\4.0.8\cores\arduino/api/String.h:29:0,
                 from C:\Users\stier\AppData\Local\Arduino15\packages\arduino\hardware\mbed_nano\4.0.8\cores\arduino/api/IPAddress.h:24,
                 from C:\Users\stier\AppData\Local\Arduino15\packages\arduino\hardware\mbed_nano\4.0.8\cores\arduino/api/ArduinoAPI.h:30,
                 from C:\Users\stier\AppData\Local\Arduino15\packages\arduino\hardware\mbed_nano\4.0.8\cores\arduino/Arduino.h:27,
                 from C:\Users\stier\AppData\Local\Temp\arduino\sketches\FF3F1DDE54DD009E29D35E5393F4662F\sketch\sketch_oct15a.ino.cpp:1:
C:\Users\stier\OneDrive\Dokumente\Arduino\libraries\SevenSeg/SevenSeg.h:91:9: error: expected unqualified-id before numeric constant
     int _B;
         ^
C:\Users\stier\OneDrive\Dokumente\Arduino\libraries\SevenSeg/SevenSeg.h:92:9: error: expected unqualified-id before numeric constant
     int _C;
         ^

exit status 1

Compilation error: exit status 1

My problem is that when i verify this code with the arduino mega 2560 it runs perfectly fine, but when I verify it on the nano rp2040 connect it gives me that error message.

What can I do to make it work on the Nano and what is the problem?

2

That's a bug in the SevenSeg library: the identifiers _B and _C are reserved. Identifiers - cppreference.com

Identifiers that appear as a token or preprocessing token (i.e., not in user-defined-string-literal like operator ""id) of one of the following forms are reserved:

  • identifiers with a double underscore anywhere;
  • identifiers that begin with an underscore followed by an uppercase letter;
  • in the global namespace, identifiers that begin with an underscore.

This has been raised as an issue on GitHub: _B and _C fields collide with esp-idf's newlib's ctype.h · Issue #10 · sigvaldm/SevenSeg · GitHub
But there's no response from the owner, and there has been no activity for 6 years, so I would recommend using a better seven segment display library.

2 Likes
3

ok can you recommand one?

5

IDE 2.x and it works on the Mega 2560 but not on the Nano rp2040 connect.

6

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