Compiler/TM4C1294NCPDT: Open a file with variable name in Fatfs operation

Alesh Mahajan

Part Number: TM4C1294NCPDT

Tool/software: TI C/C++ Compiler

Hello,

I work around Tiva C 1294 launchpad and SD card for a project of data-logger. General overview of my SD card operation is like below:

iFResult = f_mount(0, &g_sFatFs);
if(iFResult != FR_OK)
{
// UARTprintf("f_mount error: %s\n", StringFromFResult(iFResult));
return(1);
}
iFResult = f_open(&g_sFileObject, "a.txt", FA_CREATE_NEW);

The thing I want to try is change "a.txt" to a dynamic file name which can be changed during run-time.

Problem is the f_open accepts only 'const TCHAR' datatype, how can be this achieved?

Example of file name every day i wish to add according to time : May1st.csv , May2st.csv etc

over 7 years ago

0 Bob Crosby over 7 years ago

TI__Guru 72500 points

Take a look at the implementation done in sd_card.c (C:\ti\TivaWare_C_Series-2.1.4.178\examples\boards\dk-tm4c129x\sd_card). The string "g_pcTmpBuf" is declared in line 99.

static char g_pcTmpBuf[PATH_BUF_SIZE];

There is a call to f_open in line 1274.

    //
    // Now finally, append the file name to result in a fully specified file.
    //
    strcat(g_pcTmpBuf, argv[1]);

    //
    // Open the file for reading.
    //
    iFResult = f_open(&g_sFileObject, g_pcTmpBuf, FA_READ);

It is the pointer that is constant, not the characters in the string that is pointed to.

Arm-based microcontrollers

Arm-based microcontrollers forum

Compiler/TM4C1294NCPDT: Open a file with variable name in Fatfs operation