Unable to get RAM Disk as USB MSD for mbed & Nucleo-F401-RE

[JShah.10]

Hi,

I am new to mbed and STM32-F401RE.

I am trying to get the RAM Disk as USB Mass storage device and communicate between PC and STM board. I am trying https://os.mbed.com/users/va009039/code/F401RE_USBMSD_RAM/

I am able to run the binary but board is not detected as USB Drive on the Windows.

1. define PACKET_SIZE 32
2. define blocks_data (1024 * 512)

FATFileSystem fs("fs");

SERIAL setup Serial pc(USBTX, USBRX, 230400);

THREADs Thread ramfs_thread;

void ram_disk_setup() { int connect1 = 0;

/* Size of RAM file system exposed to PC as USB MassStorage */ HeapBlockDevice heap_bd(blocks_data, 512);

MBRBlockDevice::partition(&heap_bd, 1, 0x0b, 0, 512 * 512);

MBRBlockDevice part1(&heap_bd, 1);

RAMFS ramfs1("ram1", &part1);

format with FS FATFileSystem::format(&part1); create FS object and mount FS FATFileSystem fat1("fat", &part1);

USBRAMFS usbmsd1(&ramfs1);

now we wait for the user to connect the board to the PC while(true) { if (usbmsd1.connect() && 1 != connect1) { connect1 = 1; printf("Connected to PC - 1\r\n"); }

only try once per second Thread::wait(9000); } }

int main(void) { osStatus err; wait(5);

printf("\r\nUSB Serial done\r\n");

err = ramfs_thread.start(callback(ram_disk_setup)); if (err) { printf("ERROR > send_hid_thread not created\r\n"); } ramfs_thread.join(); }

Thank you in advance.

Regards,

Jignesh

[Tesla DeLorean]

You'd have to add a USB port to the F401RE to be able to talk to it via USB.

The USB on the NUCLEO-64 boards talks to the F103 implementing the ST-LINK/mbed functionality.

[JShah.10]

Thank you for the response. Yes, I have made a custom connector to connect with PC.

I really am not sure what you meant by "The USB on the NUCLEO-64 boards talks to the F103 implementing the ST-LINK/mbed functionality."

[JShah.10]

When I debugged the USB stack further, I figured that in SCSI communication Host request for READ 10 command but STM32 board sends negative acknowledgment to Host.

Due to this Host sends reset packet to STM32 board.

[Tesla DeLorean]

The board has a USB connector, it communicates with the STM32F103 chip, and NOT the STM32F401RE, that's what I said/meant.

[Tesla DeLorean]

This probably not the best place to discuss mbed coding.

I will observe that the F401 doesn't have 512KB of RAM, so a RAM drive of that size, or 256KB, probably isn't going to be viable.

[JShah.10]

Here is a setup image which I am using. I am using a custom connector on CN10 to have USB connector.

https://os.mbed.com/users/va009039/notebook/F401RE_USBDevice/#commentform

Here there is a code which says to create a RAMdisk and configure as MSD which can be detected on USB and work as USB MSD.

[JShah.10]

JFYI - I tried with lesser size of RAM drive as well... tried for 64KB also..

[Tesla DeLorean]

I've created working SDRAMDisks using the STM32F429I-DISCO, I think ST has some examples also, but these are stand-alone C projects, not built against mbed libraries.

STM32Cube_FW_F4_V1.21.0\Projects\STM32F429I-Discovery\Applications\FatFs\FatFs_RAMDisk

[dbgarasiya]

you just have to configure RAM DISK well & make some changes in usb_storage file it will show drive automatically

you don't have to change anything in main file .

Best of luck