USBHost library now in Beta!

Last updated 14 Mar 2013, by Samuel Mokrani. Host, hub, keyboard, Mouse, MSD, rtos, Serial, USB

We are pleased to release a new library: USBHost!

/media/uploads/samux/_scaled_usb_host_app_board.jpg

About the USBHost library

A USBHost library has been developed in order to communicate with USB devices. Currently, the library supports:

  • USB mice
  • USB keyboards
  • Mass storage devices
  • Virtual serial port devices

In addition to the drivers already implemented, the USBHost stack provides some cool features of USB such as:

  • Hub auto-detection
    • You can use exactly the same code if you are using a hub to connect a usb device to an mbed
  • Plug n Play support
    • You can detect when a device is attached and detached to and from the usb bus

Where to get started?

Hardware details and helloWorld examples are provided in order to get started quickly with the USBHost library:

Community contribution

It would be great if the USBHost stack development involves several developers. There is plenty of work to be done such as:

  • core modification by adding support of isochronous transfer
  • develop drivers on top of the USBHost stack:
    • Bluetooth class
    • Webcam class
    • ...

Any contribution from the mbed community would be greatly appreciated!

Have fun with USBHost!

7 comments on USBHost library now in Beta!:

Shane Spencer
18 Mar 2013

It is a great news but please assist me how to do so that i can do from my own.

http://www.asyana.com.au/

ceri clatworthy
18 Mar 2013

Just tryed the USB Host Serial, Nothing realy appears to happen,

Also, how do I get my MBED, to send serial,

I have attempted to use the code with an FTDI Serial <-> USB cable,

and a second MBED (M0) as device, sending short message repeatedly,

Reset MBED ..
MBED - active @ 10:10:46
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:130]usb_thread could not read dev descr
[USB_ERR: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp[USB_INFO: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:158]New device connected: 10002acc [hub: 0 - port: 1]
[USB_INFO: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHostSerial/USBHostSerial.cpp:71]New Serial device: VID:0d28 PID:0204 [dev: 10002acc - intf: 2]
[USB_WARNING: /workspaces/USBHostSerial_HelloWorld/src/USBHost/USBHost/USBHost.cpp:238]td 20080410 processed but not in idle state: USB_TYPE_DEVICE_NOT_RESPONDING_ERROR [ep: 1000176c - dev: 10002acc - Serial]

but does not appear to do anything,

..

The HOST MBED is in a coolcomponents workshop board,

with & withought resistors ??

Cheers

Ceri

Tick Tock
20 Mar 2013

Does this library support long filenames and properly timestamp the files when accessing MSD's?

Samuel Mokrani
21 Mar 2013

@Ceri: i don't understand how you are using the ftdi cable. Actually i tested the USBHostSerial class with an mbed plugged into another mbed over USB. So it should work :) To send serial messages:

  • from the usb host mbed: use 

USBHostSerial serial;
serial.printf("hello\r\n");
  • from the other mbed: 

Serial pc(USBTX, USBRX);
pc.printf("hello again\r\n");

@Tick Tock: Yes the library supports timestamp and long file names. The fat file system used in this library is the same as the one used for the sd filesystem

ceri clatworthy
25 Mar 2013

Is there any way to sent USB Serial (Host) messages from with-in the main loop ??
so far tthe only way to do it is to set a flag in my main, and test it in the thred.

As for the FTDI cable, (which did not get recognised by my MBED)
I pluged it (the USB end) into my coolcomponents MBED board.
and tested the code, with , and withought the pull resistors.

Cheers

Ceri

Tim Barry
26 Mar 2013

Hi Ceri,

It is my understanding that the FTDI USB<=>Serial cables need the FTDI virtual com port driver to be installed on the host (usually a pc) to allow the device to be recognised and configured - see http://www.ftdichip.com/Drivers/VCP.htm. Since there is no driver that we can install on the mbed, the converter device in the cable will not be recognised.

Tim

Mark Bauer
27 Mar 2013

Why are you looking to use ftdi serial when the unit has 3 rs232 ports built in?

Surely a cheap wifi solution is more interesting? or am i missing something?

(just my 2p).

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