EK-TM4C1294XL: Writing data to USB Stick/Pen Drive using TM4C129X

Hello Sumit,

Can you explain what you mean by define pin for USB?

Reading and writting requires API. The example usb_host_msc does one aspect of the file access, you can use the same to add write to the code.

Hello Amit,

I mean to say that for SD card I have to define Pins for SSI connection.
The USB port in the launchpad is connected via UART(that's what my understanding says) . I've seen in EKTMC123G launchpad, the USB0 is connected to PB0, PB1. In EK-TM4C1294XL launchpad(which I'am using) I cannot find the default pins connected to USB port.

I'am sorry for asking this query because I'am trying to learn USB for the first time .

Hello Amit,

elaborating my previous post , I meant that for writing data into SD card, There is mmc-ek-tm4c1294xl.c file in which SPI connections are defined and power_on() & send_initial_clock_train() functions are available to configure SPI connection & start transmitting data by using f_write() function.

However, there is no such file for USB. How to configure data transmit & receive pins for USB? or is there a default connection in launchpad for the same?

Hello Sumit

The USB data pins are not connected to PB0 and PB1 on the EK-TM4C123GXL. PB0 and PB1 is VBUS and ID pins. To understand which pins to be used for USB on the EK-TM4C1294XL please refer to the datasheet for the device part number

Hello Amit,

Thanks for your suggestions. I tried implementing the USB_HOST_MSC.C file & was successfully able to detect the pen drive and look at the files on the serial terminal.
I also tried using f_write function in the same way as f_read has been used but could not create a new file and write data into it.

Hello Sumit,

Though the device is different but the function usage should remain the same in example

D:\ti\TivaWare_C_Series-2.1.3.156\examples\boards\dk-tm4c123g\qs-logger

File Name: usbstick.c

Function Name: USBStickOpenLogFile

Hello Amit,

Bingo!!! Finally I 'am able to write the data in the USB stick. Thanks a lot for your help

But, there is also some garbage value being written. I tried using f_lseek() function but still garbage value is there. below are the lines of code & attached is the excel sheet in which data is written.

while(1)

   {

uint32_t a=0;

    if(g_eState == STATE_DEVICE_READY)

            {

               fresult = f_open(&g_sFileObject, "test47.csv", FA_WRITE|FA_OPEN_ALWAYS);

                    if(fresult != FR_OK)

                    {

          

                    }

                    char fileHeaders[] = "sensor1,sensor2,sensor3,sensor4\r\n";

                    fresult = f_write(&g_sFileObject, fileHeaders, sizeof(fileHeaders), &ui32BytesWrite);

fresult = f_lseek(&g_sFileObject,f_size(&g_sFileObject));

                    char valueStr[150];

                    for(a=100;a<=249;a++)

                    {

                    usprintf(valueStr,"%d,%d,%d,%d\r\n",a,a,a,a);

                  

                    fresult = f_write(&g_sFileObject, valueStr, sizeof(valueStr), (UINT *)&ui32BytesWrite);

                    }

                    fresult= f_close(&g_sFileObject);

            }

0654.TEST42.rar

Hello Sumit

Please check the example code for SPMA076 (opus Audio Codec). It shows how to use f_lseek

Hello Amit,

I went through the opus_enc_dec.c file. inside
int Cmd_decode(int argc, char *argv[]) function the only place where f_lseek() is used as mentioned below

//
// Go back to top of the file to update the Size of the file
//
f_lseek(&g_sFileWriteObject, 0);

Hello Sumit

And the issue is? You can look at examples provided on the FatFS on elm-chan.org/.../00index_e.html

Hello Amit,

I studied how to use the f_lseek() function & also applied it in my code. I was able to append new data in the file , Move to top of file , add no. of BYTES.

However, I'am still not able to get rid of garbage data. Is there some other reason for the unwanted data being displayed.

Could you try the same code at your end. Iam just not able to debug it.

Hello Sumit,

Please explain what do you mean by garbage data?

hello amit,

kindly see the attached excel file. The first row of "sensor1" contains garbage data.

4118.0654.TEST42.rar

Hello Sumit,

What does the variable containing the sensor1 data show when you debug the program?