XMEGA-A1 Xplained board, AT32UC3B1256 board controller, USB connection upgrade

Go To Last Post
4 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hello,

 

I have a XMEGA-A1 Xplained board which I am building a fast data logger project. The XMEGA device is quite capable and as I have progressed with the development work, the amount of data is quickly growing. In my application, I am writing all the acquired data out to a PC. Currently via UART-USB brigde through the AT32UC3B1256 board controller. The UART-USB bridge works but is increasingly becoming a bottleneck with the data throughput. I am using 57600 baud on the UART, I have tried 115200 baud, couldn't make it work. I am trying to solve the data throughput bottleneck problem, here are some ideas:

 

1. Make the existing UART-USB bridge run at 115200 bd or faster? 115200 bd would only provide 2x speed-up, which would be less than I'd need. And I have read that 115200 bd is the maximum for the UART on XMEGA.

 

2. Could the AT32UC3B1256 board controller firmware be upgraded (via JTAG) to go above 115200 bd? Anybody know such solution? How about using the SPI or TWI, which are mentioned in AVR1924:

 

"The AT32UC3B1256 is also connected to the shared SPI and TWI lines, and so it is also possible to add TWI and SPI gateway functionality for these serial interfaces, if desired. This gateway functionality is not available in the default firmware for the AT32UC3B1256. Please refer to the schematics for more information about these connections."

 

Has anybody done this and could that enable 1M speeds for USB?

 

3. My data is in text format, in short lines like (nn.nnnn nnn.nn). Could I pack it using f.ex. ZIP protocol, transfer it over UART-USB in binary and save as ZIP file on PC?

 

4. Is it possible to make the board SDRAM available as mass storage via the AT32UC3B1256. My application could first do the data acquisition and organize it in file system format into a RAM disk. Then it could switch to mass storage mode and enable Access via UART/SPI/TWI-USB?

 

5. Should I upgrade to a more capable board with mass storage readily available (worst and last option)?

 

I'd welcome any thoughts, ideas and information on this issue.

 

Thank you!

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

tapiov wrote:
And I have read that 115200 bd is the maximum for the UART on XMEGA.
Device clock frequency divided by 8

ASF3 defines max at 57600; otherwise, can set it though baud accuracy depends on clock's accuracy.

tapiov wrote:
5. Should I upgrade to a more capable board with mass storage readily available (worst and last option)?
Consider porting from XMEGA128A1 to XMEGA128A1U and its USB device controller.

CodevisionAVR has USB examples.

ASF3 for Microchip (ASF4 appears to not be non-functional for XMEGA AU USB)

A few third party XMEGA128A1U boards have an SD card socket.

Microchip XMEGAA1U Xplained Pro has an I/O card with an SD socket.

 


http://asf.atmel.com/docs/latest/xmegaau/html/group__usart__group.html#ga621fa6540397b3b81a9a5176c17e782a

http://hpinfotech.ro/cvavr_examples.html

https://www.mattairtech.com/index.php/development-boards/mt-x1s-atxmega128a1-u-usb-development-board.html

http://www.alvidi.de/products/EN/AVR_Development_Boards/avr_modul_xavrb_v20.php

https://www.aliexpress.com/store/product/ATxmega128A1U-EK-development-board-1-8-TFT-LCD-12Bit-ADC-and-DAC-8-USARTs-PDI-JTAG/800571_32827450345.html

http://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=ATXMEGAA1U-XPRO

http://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=ATIO1-XPRO

 

"Dare to be naïve." - Buckminster Fuller

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

2. Could the AT32UC3B1256 board controller firmware be upgraded (via JTAG) to go above 115200 bd? Anybody know such solution? How about using the SPI or TWI, which are mentioned in AVR1924:

 

"The AT32UC3B1256 is also connected to the shared SPI and TWI lines, and so it is also possible to add TWI and SPI gateway functionality for these serial interfaces, if desired. This gateway functionality is not available in the default firmware for the AT32UC3B1256. Please refer to the schematics for more information about these connections."

 

Has anybody done this and could that enable 1M speeds for USB?

AFAIK, the "default" firmware is all that is available.  Although there is an example project entitled "Board Controller" for the UC3B.  You would have to implement the extra functionality yourself unless someone has already done so and posted the project.

 

4. Is it possible to make the board SDRAM available as mass storage via the AT32UC3B1256. My application could first do the data acquisition and organize it in file system format into a RAM disk. Then it could switch to mass storage mode and enable Access via UART/SPI/TWI-USB?

No.  The SDRAM is interfaced to the XMEGA, not the UC3. 

 

5. Should I upgrade to a more capable board with mass storage readily available (worst and last option)?

Probably.

 

 

Greg Muth

Portland, OR, US

Atmel Studio 7.0 on Windows 10

Xplained/Pro/Mini Boards mostly

 

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thank you all for answers and ideas. 

 

I have been able to cut down the data amount to transfer. I will continue it further and do even more pre-processing on XMEGA to reduce data amount.