CmdMessenger won't compile on Thing Plus

Development Boards ESP32
1

Hello!

First post! Please let me know if I commit any faux pas.

I have been using the cmdMessenger library to build communication interfaces for a while now, and am pretty familiar with it. However, it does not seem to want to compile on my ESP32 Thing-Plus. I receive the below error.

Any experience with this, or similar stuff? This library works great for me on any number of other uControllers, so this is a bit of a conundrum for me.

Thanks,

Nate

Arduino/libraries/CmdMessenger/CmdMessenger.cpp: In member function 'char* CmdMessenger::readStringArg()':
Arduino/libraries/CmdMessenger/CmdMessenger.cpp:492:9: error: invalid conversion from 'char' to 'char*' [-fpermissive]
  return '\0';
         ^~~~
exit status 1
Error compiling for board SparkFun ESP32 Thing Plus.
2

I haven’t seen that before, but almost every time I have a compile error for esp32 it’s because arduino has gotten the board definitions mixed up somehow; try wiping the board def folder like so https://support.arduino.cc/hc/en-us/art … rduino-IDE (delete the add’l files folder and re-install the board definitions) and try again

3

Howdy!

Thanks for getting back to me. I deleted the contents of my Arduino 15 folder, and removed the ‘espressif’ folder from the ‘hardware’ folder as well. Let me know if this is what you were thinking.

Then, I reinstalled the board definition as shown here: https://learn.sparkfun.com/tutorials/es … okup-guide

I continue to get the same error though, even in a blank sketch with only the #include statement. Let me know if you have any further suggestions! I’d really love to continue to use cmdMessenger, and I have to imagine this is some subtle issue in the compiler.

4

Some compilers are more strict than others on some definitions. The new 3.0.4. ESP32 has been causing me compiler errors I did not have before.

In the file : Arduino/libraries/CmdMessenger/CmdMessenger.cpp

line 492 change

return '\0';

to

return (char *) '\0';

THAT error message is solved.

But NOW I got the next one :

Arduino/libraries/CmdMessenger/utility/HeaterSim.cpp:73:72: error: no matching function for call to 'max(long unsigned int, int)'

In the file : Arduino/libraries/CmdMessenger/utility/HeaterSim.cpp

change line 73 from

if (currentTime >= _lastTime) _deltams = max(currentTime - _lastTime, 1);

to

if (currentTime >= _lastTime) _deltams = max(currentTime - _lastTime, (unsigned long) 1);

Now it all compiles (for me :-))