How to Data Read or Write in USB(Full Speed/High Speed)

aajithkumarr — Fri, 26 May 2023 10:23:23 GMT

Hi NXP Team

I am beginner to the NXP controllers,I am currently working on a board OM13098LPCxpresso54628.I am trying create a new txt file write some data on to it in microUSB port J2/J3.I am using the example project provided in the SDK example(host_msd_fatfs_bm).USB Device was connected to the micro AB port to USB(J3) was detected. But i was structed in where to open the file and write the file.

In main function

USB_HostTaskFn(g_HostHandle);
USB_HostMsdTask(&g_MsdFatfsInstance);

function was called but i dont know how to write data onto the file.Is there any function i need to call.

Please provide me the example project which can open the file and write the data onto it or provide how to i start working. what are the procedure i need to follow.

Kindly help me.

Best regards,

A. Ajith Kumar

Re: How to Data Read or Write in USB(Full Speed/High Speed)

RaRo — Mon, 29 May 2023 18:53:50 GMT

Hello @aajithkumarr,

The SDK example(host_msd_fatfs_bm) that you are using is the recommended one to start to open, create, write and read files.

Follow the next steps to find the relevant functions to open and write a file to the USB in the example:

Ctrl + click on USB_HostMsdTask(&g_MsdFatfsInstance);

[app.c file in host_msd_fatfs_bm SDK example]

Then in the function search for USB_HostMsdFatfsTest(msdFatfsInstance); and ctrl + click on it.

[host_msd_fatfs.c file in host_msd_fatfs_bm SDK example]

Now you are in the function that performs all the testing/actions this example mentions in the readme.pdf file.

Nonetheless, the file opening and writing is almost at the end of the function. You may want to search for the following line that starts the open/create a file test: usb_echo("file operation:\r\n");

[host_msd_fatfs.c file in host_msd_fatfs_bm SDK example]

In here you will find the f_open function that is used for open/creating a non-existing file, while f_write is used for writing onto the file.

We recommend you work with the example, and to debug it to see how it works.

Caution: The SDK example erases all the content of the connected USB stick (performs a format).

Best regards, Raul.

LPC MicrocontrollersのトピックHow to Data Read or Write in USB(Full Speed/High Speed)

How to Data Read or Write in USB(Full Speed/High Speed)

Re: How to Data Read or Write in USB(Full Speed/High Speed)