AVR-Chat

Looking into this a little further, it seems that the AVR32 (specifically
the AVR32UC3A3) has an SDIO interface as well as high speed USB, with DMA
transfer between these peripherals. That is looking to be a fairly
economical choice, though I need to look into it  little further.

The best I could theoretically get with the XMEGA is the SPI bus speed of
16MHz (assuming system clock at 32MHz), which would be around 2MBps, and
that is best case - in reality it would be less. The AVR32 natively supports
the full 4 bit mode SDIO and with the higher clock speed of the AVR32
it should be significantly faster? I'm trying to find some real world
examples that give me a realistic idea of read/write speeds to/from SD and
USB with the AVR32.

Also planning to use the Venus GPS chip - anyone have any experience good or
bad with this GPS?

Otherwise the XMEGA A1 looks like it would be awesome for a datalogger with
8 timer channels, 16 12bit AD convertors, and lots of highly configurable IO
ports. The only limiting factor would be the transfer speed from SD card to
USB (using say the FTDI FT245R for USB). If transferring a theretical 2GB of
data, that could take a long time. Does anyone have any suggestions as to
how that could be sped up - maybe using an FPGA to handle the USB download?

On Fri, Feb 5, 2010 at 1:55 AM, Roland Jollivet
<Roland.Jollivet@gmail.com>wrote:

> I don't know how the prices compare, but how about using a Ramtron device
> for storage?
>
> Roland
>
> www.ramtron.com
>
>
> On 4 February 2010 03:51, Dean Claxton <deanclaxton@gmail.com> wrote:
>
> >
> >
> > Ok thanks guys,
> >
> > I too plan just to use it for internal storage - it would not be
> accessible
> > to the end user without opening the case. Download would most likely me
> via
> > USB, but it seems the the XMEGA's dont feature USB.
> >
> > Perhaps I should start looking at the AVR32 as the external memory bus
> > would
> > also allow the use of SRAM as an option.
> >
> > Dean
> >
> > On Wed, Feb 3, 2010 at 12:39 AM, Tim Mitchell <tim@sabretechnology.co.uk
> <tim%40sabretechnology.co.uk>
> > >wrote:
> >
> >
> > > ----Original Message----
> > > From: AVR-Chat@yahoogroups.com <AVR-Chat%40yahoogroups.com>
> > > [mailto:AVR-Chat@yahoogroups.com <AVR-Chat%40yahoogroups.com>] On
> Behalf
> > Of Dave
> > > McLaughlin Sent: 02 February 2010 11:58 To:
>  > > AVR-Chat@yahoogroups.com <AVR-Chat%40yahoogroups.com> Subject: RE:
> > [AVR-Chat] Looking at
> > > doing a datalogger using an XMEGA part - not sure which
> > > storage technology to use
> > >
> > > > This all seems to be a grey area and there is no definite
> > > > answer on their
> > > > website. In fact, it is impossible to determine if you
> > > > need this just to
> > > > have the hardware present. I have no plans to show any
> > > > kind of reference to
> > > > SD in my product or even have external access to it and I
> > > > can't find any
> > > > information as to whether I need a license or not?
> > >
> > > They are trying to get you to join so I suppose it's not in their
> > > interests to make it clear!!
> > >
> > > If you google a bit there seems to be a consensus that no license is
> > > required if you use basic SPI to access the card as there is no patent
> > > covering this. The license/patents appear to cover a proprietary method
> > > of accessing the card. I have no way of verifying this information.
> > >
> > > I guess you have to decide if you are prepared to run the (small) risk
> > > of them coming after you for possible patent infringement.
> > >
> > > --
> > > Tim Mitchell
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> >
> > --
> > Kind Regards
> > Dean Claxton
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
>  Yahoo! Groups Links
>
>
>
>


-- 
Kind Regards
Dean Claxton


[Non-text portions of this message have been removed]