Library example can not be adapted for SdFat.h

[drp0]

I have tried converting the library utft example to SdFat.

I edited User_Config in JPEGDecoder\src to allow #define LOAD_SDFAT_LIBRARY. I modified the example code to work with the latest SdFat version. The code will not compile with all errors pointing to SD.open in JPEGDecoder.cpp:

c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp: In member function 'int JPEGDecoder::decodeSdFile(const char*)':
c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp:353:17: error: 'SD' was not declared in this scope
  File pInFile = SD.open( pFilename, FILE_READ);
                 ^~
c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp:353:17: note: suggested alternative: 'SDA'
  File pInFile = SD.open( pFilename, FILE_READ);
                 ^~
                 SDA
c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp: In member function 'int JPEGDecoder::decodeSdFile(const String&)':
c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp:362:17: error: 'SD' was not declared in this scope
  File pInFile = SD.open( pFilename.c_str(), FILE_READ);
                 ^~
c:\Users\User\Documents\Arduino\libraries\JPEGDecoder\src\JPEGDecoder.cpp:362:17: note: suggested alternative: 'SDA'
  File pInFile = SD.open( pFilename.c_str(), FILE_READ);
                 ^~
                 SDA

Basically SdFat does not recognise SD.open.. Should it be:

File someHandle;
bool fok = somehandle.open(someFilename, O_RDONLY);

With this change in JPEGDecoder.cpp the example compiles but does not work.

David

[drp0]

I now have a version working JPEGdecoder.cpp has a couple of references to parameters passed as File type. This limits what you can do without serious rewriting. Certainly the use of fat32 would require a re-write. It is possible to use Sdfat with..

define SPI_CLOCK SD_SCK_MHZ(50)

define SD_CONFIG SdSpiConfig(sdSelect, DEDICATED_SPI, SPI_CLOCK)

SdFat sd; // not SdFat32 sd

if (!sd.begin(SD_CONFIG)) { Serial.println(F("sd.begin failed")); return; }else Serial.println(F("SD ok"));

File something; // not File32 something

Note that JPEGDecoder.cpp does not differentiate between fat and sd. I suggest the following amendment which allows decodeSdFile to work:

#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)

// Call specific to SD filing system in case leading / is used
int JPEGDecoder::decodeSdFile(const char *pFilename) {
    File pInFile;
        #if defined (LOAD_SD_LIBRARY) 
        pInFile = SD.open( pFilename, FILE_READ);
        #endif
        //drp
        #if defined (LOAD_SDFAT_LIBRARY)
        pInFile.open(pFilename, O_RDONLY);
        #endif 
    return decodeSdFile(pInFile);
    }

int JPEGDecoder::decodeSdFile(const String& pFilename) {
#if !defined (ARDUINO_ARCH_SAM)
    File pInFile;
        #if defined (LOAD_SD_LIBRARY) 
        pInFile = SD.open( pFilename.c_str(), FILE_READ);
        #endif
        // drp
        #if defined (LOAD_SDFAT_LIBRARY)
        pInFile.open(pFilename.c_str(), O_RDONLY);
        #endif
    return decodeSdFile(pInFile);
#else
    return -1;
#endif
}

David

[Bodmer]

Thanks for the example code.