ASF4 MSC slave - mass storage on SD card

Log in or register to post comments
Go To Last Post
5 posts / 0 new
Author
Message
DFOWE
DFOWE's picture
Level: New Member
Joined: Tue. Apr 2, 2019
Posts: 6 View posts
#1
Posted by DFOWE: Tue. Dec 3, 2019 - 03:27 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hi all,

 

Before I begin - I've raised a ticket with Microchip support and received nothing after 1 week. This is a HUGE stumbling block and any help would be appreciated.

 

I'm trying to change the MSC device drivers such that they use a FATFS formatted SD card rather than exposing 22KB of RAM. It appears that this example/demo code was dropped by Atmel/Microchip as all the functionality to do this is missing.

 

I'm lost with what needs changing to accomplish this. I have a known good SD interface with good FATFS drivers (though f_gets doesnt seem to work correctly).

 

I'm assuming that within the call to "msc_usb_task", I need to read from the SD card via calls to "disk_read" in "sdmmc_diskio.c". I really dont know at which "level" of START I'm supposed to tie all of this together.

 

 

Tags:

Tools, Atmel Software Framework (ASF) and Atmel Start (ASFv4) (ARM-related)
Last Edited: Tue. Dec 3, 2019 - 07:53 PM
Top
Bronze Markawneil
awneil's picture
Level: 10k+ Postman
Joined: Fri. Jul 1, 2005
Posts: 25317 View posts
Location: Basingstoke, Hampshire, UK
Posted by awneil: Tue. Dec 3, 2019 - 03:35 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

DFOWE wrote:
I'm trying to change the MSC device drivers

Do they work "as-is" - before any changes?

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillator: https://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Top
DFOWE
DFOWE's picture
Level: New Member
Joined: Tue. Apr 2, 2019
Posts: 6 View posts
Posted by DFOWE: Tue. Dec 3, 2019 - 03:50 PM (Reply to #2)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The example supplied in START would create a 22KB buffer in RAM and this was exposed to the MSC, so to speak. When the device is plugged into my PC, I would receive an error that there was (obviously) no file system available on the 22KB and prompted to format the RAM. This seems to work correctly. As mentioned it appears that some thought was given to tying an external memory to this but was not completed.

 

I've attached the demo I'm working from.

Attachment(s): 

Package icon USB MSC_SAME54_ORIGINAL_22KBRAM.zip
Top
DFOWE
DFOWE's picture
Level: New Member
Joined: Tue. Apr 2, 2019
Posts: 6 View posts
Posted by DFOWE: Tue. Dec 3, 2019 - 03:57 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

There is an option in START, for this example, to use an SD card. Selecting the checkbox to enable that options doesnt seem to do anything!

Top
Bronze Markawneil
awneil's picture
Level: 10k+ Postman
Joined: Fri. Jul 1, 2005
Posts: 25317 View posts
Location: Basingstoke, Hampshire, UK
Posted by awneil: Tue. Dec 3, 2019 - 06:10 PM (Reply to #3)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

DFOWE wrote:
USB MSC_SAME54_ORIGINAL_22KBRAM.zip

So not an AVR, then?

 

Maybe try: https://community.atmel.com/foru...

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillator: https://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Top