[solved] Building New Library -> Serial Errors

Hey guys,

I'm currently trying to make a faster and simpler version of the DFPlayerMini library. I've already validated the individual functions without making a standalone library.

Now that I'm trying to make a library for it (my first library BTW) the main problem I'm having is that when I upload my library to the IDE, include the library, and compile, I get the following errors:

Arduino: 1.8.2 (Windows 10), Board: "Arduino/Genuino Uno"

WARNING: Category '' in library Neotimer is not valid. Setting to 'Uncategorized'
C:\Users...\Documents\Arduino\libraries\DFPlayerMini_Fast-master\DFPlayerMini_Fast.cpp: In member function 'void DFPlayerMini_Fast::sendData(uint8_t, uint8_t, uint8_t, uint8_t, uint8_t)':

C:\Users...\Documents\Arduino\libraries\DFPlayerMini_Fast-master\DFPlayerMini_Fast.cpp:68:26: error: call of overloaded 'write(int)' is ambiguous



C:\Users...\Documents\Arduino\libraries\DFPlayerMini_Fast-master\DFPlayerMini_Fast.cpp:68:26: note: candidates are:

In file included from C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Stream.h:26:0,

from C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/HardwareSerial.h:29,

from C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Arduino.h:232,

from C:\Users\Luke\Documents\Arduino\libraries\DFPlayerMini_Fast-master\DFPlayerMini_Fast.h:1,

from C:\Users\Luke\Documents\Arduino\libraries\DFPlayerMini_Fast-master\DFPlayerMini_Fast.cpp:1:

C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Print.h:51:20: note: virtual size_t Print::write(uint8_t)

virtual size_t write(uint8_t) = 0;


C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Print.h:52:12: note: size_t Print::write(const char*)

size_t write(const char *str) {


exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

As for the "_serial->write(FEEDBACK);" error, I'm not sure how to fix it since FEEDBACK only has value 0 and is within scope (global #define in header).

All of the other errors, I have very little idea what is even wrong, much less how to fix it.

Any ideas? Thanks!

BTW, the repo is here.

Actually, I figured it out and it works now!!

Check out the link for the updated (and working) version.