Hi, can anyone tell me what is the problem when I uploading? Below is the error messages. Thanks.
Arduino: 1.8.16 (Windows 10), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)" libraries\TMRpcm-master\TMRpcm.cpp.o (symbol from plugin): In function `optionByte': (.text+0x0): multiple definition of `a' sketch\test_change_code.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here collect2.exe: error: ld returned 1 exit status exit status 1 Error compiling for board Arduino Mega or Mega 2560. This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences.