| Author |
Message |
|
|
 Posted: Jul 18, 2007 - 06:39 PM |
|
Joined: Jun 26, 2007
Posts: 16
|
|
How to implement both a Mass Storage Interface and a CDC interface on one device. The tutorial is in pdf form. Please feel free to comment with suggestions, typos etc.
Abstract
It is convenient to be able to have a mass storage device functioning, and also have two way communication to and from the same device over the same physical connection. As the mass storage device takes 2 endpoints (in addition to the required control endpoint 0) and it is possible to have uart over usb through the cdc interface (which requires 3 endpoints). We use a standard development kit and existing code examples to show the feasibility of creating such a device. The following tutorial describes the integration of the Atmel Mass Storage and CDC examples as well as the driver modification which must take place in order to have a device which successfully functions as a composite device simultaneously allowing a mass storage device and com communication. |
|
|
| |
|
|
|
|
|
|
Posted: Apr 23, 2008 - 08:18 AM |
|
Joined: Apr 22, 2008
Posts: 8
|
|
| Hi Mikeboro, I had a question for you. I am trying to keep the virtual port I get from the cdc code so that I could communicate with the At90USBkey using Labview via the virtual port while I test some other code on the microcontroller. Do you know how I can do this? Everytime I download new code to the board using Flip, the virtual port disappears because I have erased it. How can I keep it and still download new code for testing with Labview? Any help will be highly appreciated. Thanks |
|
|
| |
|
|
|
|
|
|
Posted: May 04, 2009 - 09:58 PM |
|
Joined: Apr 20, 2009
Posts: 4
|
|
Very well done, and the tutorial certainly points out the main files that must be updated to get CDC + MS to work concurrently. I wasn't able to get it working, but instead what I did was to start with Atmel CDC's example, then I merged the relevant MS code. Attached is a tar of the original relevant file list (orig), and then the modified files list (new). It compiles and works! However, it is not necessarily very robust (seems that CDC operations might corrupt the FAT16 file structure; e.g. volume sector... I'm still investigating).
My setup is:
- Ubuntu 9.04
- code::blocks IDE (fantastic... supports the AVR90 uP right out of the box)
- you can use the Meld Diff viewer to highlight the diff's in the files if you are using linux (great app!)
- AT90USBKEY hardware
Good luck!
P.S. If you're not using Linux... then WHY NOT??!!  |
|
|
| |
|
|
|
|
|
|
Posted: May 04, 2009 - 10:05 PM |
|
Joined: Apr 20, 2009
Posts: 4
|
|
By the way, I should have mentioned that with Ubuntu 9.04, I didn't have to do anything with drivers like it appears you have to do with Windoze. It just works. If you type "dmesg" at the command prompt with Linux, you'll see both the CDC and MS interfaces load. Here's an example output:
[ 8275.108079] usb 3-1: new full speed USB device using ohci_hcd and address 3
[ 8275.320547] usb 3-1: configuration #1 chosen from 1 choice
[ 8275.323254] cdc_acm 3-1:1.0: ttyACM0: USB ACM device
[ 8275.329703] scsi5 : SCSI emulation for USB Mass Storage devices
[ 8275.330037] usb-storage: device found at 3
Also, I use dfu-programmer to program the USBKEY... very nice little utility that can be easily run using a script. Make programming very fast and convenient. There's a tutorial online on how to configure & use it. |
|
|
| |
|
|
|
|
|
|
Posted: May 11, 2009 - 12:56 PM |
|
Joined: Apr 08, 2009
Posts: 13
|
|
Hi Capa_Pinbacker
Could you please upload the hex file for your project.
I cant seem to get the MS and CDC to work together.
Im using a program called USBTrace (Shows all info of a USB port)and would like to see the flow of the enumeration. |
|
|
| |
|
|
|
|
|
|
Posted: May 11, 2009 - 03:04 PM |
|
Joined: May 11, 2009
Posts: 1
|
|
Hi All,
I am trying to get this working and I cannot finf the mass storage demo on the atmel site. Can anyone help?
I have tried using the cdc+ms.tar from above but cannot work out what goes where and how to compile it; I am using AVR studio.
Any help gratefilly received.
Thanks |
|
|
| |
|
|
|
|
|
|
Posted: May 11, 2009 - 03:21 PM |
|
Joined: Jul 18, 2005
Posts: 62227
Location: (using avr-gcc in) Finchingfield, Essex, England
|
|
|
Quote:
I cannot finf the mass storage demo on the atmel site
Rather than Atmel software you may find it easier to use "LUFA" - just Google it. |
_________________
|
| |
|
|
|
|
|
|
Posted: May 14, 2009 - 08:23 AM |
|
Joined: Apr 08, 2009
Posts: 13
|
|
Hi Capa_Pinbacker
Did you use the CDC driver (.ini file) ? |
|
|
| |
|
|
|
|
|
|
Posted: May 14, 2009 - 10:36 AM |
|
Joined: Apr 08, 2009
Posts: 13
|
|
I cant seem to recieve anything on endpoint 5 which is bulk [OUT] but im recieving the mass storage on endpoint 2 which is bulk [OUT] but is part of the cdc data class.
Does any one know why this could be ? |
|
|
| |
|
|
|
|
|
|
Posted: May 14, 2009 - 01:42 PM |
|
Joined: Apr 08, 2009
Posts: 13
|
|
Hi Sorry for spamming.
Forget all my previous question.
I got the MS+CDC to run But i got a problem.
How do you create a custom driver for the device ?
The Tutorial says check the cdc example but i cant download it and i cant find any thing on the web.
Please Help |
|
|
| |
|
|
|
|
|
|
Posted: May 15, 2009 - 03:33 AM |
|
Joined: Apr 20, 2009
Posts: 4
|
|
Attached is the hex file that I download to the device. If you open a serial program on your PC, you will see the characters echoed back.
I've also included a Linux script file which I execute to do the download.
The mass storage & CDC demos are on the Atmel site... today they're near the bottom of http://www.atmel.com/dyn/products/tools ... ily_id=607
Remember, I'm using Linux, and its USB driver works out of the box with this particular implementation. Sorry I cannot help with specific Windoze driver issues 
Creating a custom driver for Windoze or Linux is possible, you would need to learn about creating drivers on those OS's!
Good luck! I hope this works for you. |
Last edited by Capa_Pinbacker on May 16, 2009 - 05:53 PM; edited 2 times in total
|
| |
|
|
|
|
|
|
Posted: May 15, 2009 - 07:23 AM |
|
Joined: Apr 08, 2009
Posts: 13
|
|
Thanks i will compare it with the one i created.
Shortly after i posted my previous message i got my own compilation to work using Codevision.
Its working beautifully. |
|
|
| |
|
|
|
|
|
|
Posted: May 15, 2009 - 02:13 PM |
|
Joined: Jan 23, 2004
Posts: 9820
Location: Trondheim, Norway
|
|
|
Quote:
I differ on LUFA -- I found the Atmel s/w much easier to comprehend and modify. This code should compile using AVR studio and GCC compiler (I use Linux tools, but the basic idea, and GCC compiler, is the same).
Ouch, that's the exact opposite to what I was hoping for. Would you mind explaining why you didn't like LUFA, so that I can make it easier to use? Constructive criticism is gratefully received, since I want to make a better product. Perhaps via email would be best, so as not to flood this thread with too much off-topic chatter.
Cheers!
- Dean  |
_________________
Atmel Studio 6.1 is now released, grab it here.
Report AS6/ASF bugs here.
|
| |
|
|
|
|
|
|
Posted: May 16, 2009 - 05:45 PM |
|
Joined: Apr 20, 2009
Posts: 4
|
|
| I think a separate LUFA MS+CDC thread is warranted! |
|
|
| |
|
|
|
|
|
|
Posted: Dec 21, 2011 - 11:13 PM |
|
Joined: Dec 21, 2011
Posts: 1
|
|
| Thank you very much for the tutorial. I am using different hardware platform to implement the same function. |
|
|
| |
|
|
|
|
|
FAQ
Search
Register
Log in to check your private messages
Log in
Maximize
RSS
