SDFat keep file open

Projects Programming
1

I have some problems with SDFat.

My goal is to have a global SdFile rulesFile; which i read from. To minimize the time it takes reading from the file, i want to keep the file open through the execution of the program.

But for some reason i cannot get it to work. If i explicitly open the file, read from the file and close it again, I'm getting the correct data. If I'm just opening the file in the end of Setup() and and I try to read from it, I'm not getting the right data.

I suspect that the file automatically closes for some reason.. Is there a way to keep a file open?

Code for reading which exists in a library .cpp file, it has access to the global rulesFile variable.

            rulesFile.seekSet(0);

            //Read the rule from the 
            rulesFile.read(&r, sizeof(Rule));

            Serial.println(r.actions[0].duration);

This only works if I before the first line open the files, even though that i in the last line in the Setup() function calls

    if(!rulesFile.open(rulesBufFileName, O_READ))
    {
      sd.errorHalt("Error open rules for read");  
    }

Thanks in advance

2

The best advice that I can give at the moment is for you to post a complete program that illustrates the problem. If it uses a library then please post the library code or a link to it.

3

Possibly also relocate this question to the Storage board?? Just an idea..

Are you referring to SD.h built in to Arduino, or the library SdFatlib downloaded from github?

Regards,

Graham