I've been trying to develop this small routine to copy all my existing files from the onboard SD card to my USB drive utilizing the USB Host port of my LV 32MX v6. I finally got it to work with the modification I made to the example given to the PIC32 Host. But I'm having a small problem where the data can not be copied to the new created file of the USB drive. The only way it does copy the data is by me first typing some data myself into the file created on the USB drive. then my routine below will do the copying. But it only copies as many characters from the SD card to the USB drive which I typed in my self to The USB drive. It seems as though the file created in the USB drive is not usable unless you write to it yourself first like initializing the space
. It probably has something to do with the creation of the file or file format which I'm not aware of. Can please some advise me what should be done to allow my route below to automatically add or append files to the new created file without me having to open the created file on the USB drive and write characters to it in order for my routine to then be able to write to that file. I hope the explanation is pretty clear as to the problem I've added comments to help you understand what each section does to help. This is only a piece of the example which I modified to do this and which is responsisble for the problem I'm having, it will not work alone if you cut and paste but should be enough to analyze the problem. Thanks for any adviseGZoino
// Application Part
uint8_t USBHost_MSCApplication(){
switch(MSC_App_State){
case 0:
if (FAT32_Init() == 0){
TFT_Write_Text("insert sd card", 190, 190);
MSC_App_State = 1;
}else{
TFT_Write_Text("two", 120, 140);
TFT_Write_Text(msgDevFatError, 10, 20);
}
break;
// the purpose is to copy files with data from sd card to USB drive
case 1: //this routene first checks if there is any files with the names starting with 'PSC_0001.txt on the sd card, if the file exist,
//it will create the same file name to the USB drive under the PSC directory. It then copies data existing in the 'PSC_0001.txt
//file to the file from the sd card to the file which was created in the USB Drive under the same name file. this is done sequentially
//untill it doesn't find any further files in the sd card.
FAT32_MakeDir("PSC"); //{ // creates DIR_A directory on USB DRIVE
FAT32_ChangeDir("PSC"); //change directory
if(1== Mmc_Fat_Exists("PSC_0001.TXT")){ // if the first "0001.txt file exists on the sd card then execute this section
for(USB_File = 1;;USB_File++){
SPI2_Init_Advanced(_SPI_MASTER, _SPI_8_BIT, 64, _SPI_SS_DISABLE, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_HIGH, _SPI_ACTIVE_2_IDLE);
Delay_ms(10);
//--- init the FAT library
if (!Mmc_Fat_Init()) {
// reinitialize spi at higher speed
SPI2_Init_Advanced(_SPI_MASTER, _SPI_8_BIT, 8, _SPI_SS_DISABLE, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_HIGH, _SPI_ACTIVE_2_IDLE);
}
FAT32_Init();
FAT32_ChangeDir("PSC");
IntToStr(USB_File/1000, FileNum2); //this section is used to create files name starting with "0001.txt on-
filename[4] = FileNum2[5];
IntToStr(USB_File/100, FileNum2); //the USB drive which is insertec into the USB Host port.
filename[5] = FileNum2[5];
IntToStr(USB_File/10, FileNum2); //each file will be created in number sequential wise
filename[6] = FileNum2[5];
IntToStr(USB_File, FileNum2);
filename[7] = FileNum2[5];
if(1 == Mmc_Fat_Exists(filename)){
Drawbox(&Box1);
TFT_Write_Text(filename, 190, 200);
fhandle = Mmc_Fat_Open(filename, FILE_READ, 0x01);// This function opens a file for manipulation.
Mmc_Fat_Assign(filename,0x01);
position = 0;
Mmc_Fat_Seek(position);//This routine is used to set the cursor position within an opened file and returns the cursor's new position within an opened file.
Delay_ms(10);
no_bytes = Mmc_Fat_ReadN(&data_buff, 5000);//This function reads multiple bytes.
fHandle = FAT32_Open(filename, FILE_WRITE);
FAT32_Write(fHandle,data_buff, 5000);
}else if(0 == Mmc_Fat_Exists(filename)){
break;
}
}
}
// FAT32_Dir(); this display tye current directory on the usb drive
MSC_App_State = 2;
break;
case 2 :
break;
}
return _USB_HOST_MSC_CMD_PASSED;
}
