Help coding: adding functionality relying on MySensors-func/library (saveState/loadState) (c++)

[perIpI]

Im using the mySensors functions saveState and loadState to read/write to EEPROM. To facilitate I have written some small functions that do the casting so that I can save uint16_T/float/other by single function call. I would like to organize these functions in a separate file so that I can add this functionality easily to each project. However I struggle to get the structure correct and overcome a compiler warning.

I have collected the functions in .h-file and .cpp-file
Example:

//mysEeprom.h - declaration of my help-files
void save_uint16(uint8_t position, uint16_t value)
//mysEeprom.cpp
void save_uint16(uint8_t position, uint16_t value) {
    saveState(position, (uint8_t)value);
    saveState(position+1, (uint8_t)(value>>8));
}

//Project file main.cpp 
(Radio-declaration etc.) ie #define MY_RADIO_RFM69 
#include <mysensors.h>
#include <mysEeprom.h>

save_uint16(position, value);

The compiler responds that saveState "was not declared in this scope" (the saveState is decleared inside MySensors/core/MySensorsCore.h.).

To tell the compiler where to look for saveState I add an #include <mySensors.h>-statement:

//In MysEeprom.h-file
#include "mySensors.h"

This time the compiler seems to believe that I want to includes "double" mySensors.h and responds with:

.pio\libdeps\pro8MHzatmega328\MySensors/mysensors.h:426:2: error: #error No forward link or gateway feature activated. This means nowhere to send messages! Pretty pointless.

I had this message earlier when the #include <mySensors.h>-statement was positioned before #define MY_RADIO_RFM69 . Putting MY_RADIO_RFM69-statement before include <mySensors.h> solved it (ie my include-statements are put after definitions, just before declaration of global variables).

I have also experimented organizing my eeprom-functions inside a namespace and a class, but so far have not found a working solution. Help is appreciated, how should this be done, thanks!

[boum]

If you cannot include the whole mysensors header, you maybe can just forward declare the function. (basically, just copy the line from the mysensors.h in your mysEeprom.cpp file.

/*extern*/ void saveState(uint8_t pos, uint8_t value);
// extern probably not needed, that's real old C, but you I have had 
// surprises with the arduino compiler… You might need to add it.

What's the issue with namespaces or classes?

[perIpI]

@boum said in Help coding: adding functionality relying on MySensors-func/library (saveState/loadState) (c++):

/extern/

Wonderful, that did the trick! Thank you very much!

For namespace/class basically the problem was the same, without "mySensors.h" couldnt find saveState and with "include <mySensors.h>" I had "#error No forward link or gateway feature activated. This means nowhere to send messages! Pretty pointless."

[electrik]

If you want to use library functions outside the main sketch, you can also just include the core header, e.g.

#include "core/MySensorsCore.h"

[perIpI]

@electrik

Tested and worked as well. I think this is preferable over the first solution (forward function declaration) as it gives a reference where the functions are defined. Thank you!