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From: D Yuniskis on 13 Apr 2010 09:42
Hi Adrian,

Adrian C wrote:
> On 13/04/2010 10:41, Richard Rasker wrote:
>
>> The only problem I'm still facing is data storage: I'd like to use an SD
>> card (or Micro SD) to store this data, so that the user can transfer the
>> data to a PC with minimal hassle.
>
> Is selling a SD compatible device without joining the SD Card
> association really something you can get fined for?

"Technically", I think so. (practically? <shrug>)

IANAL.

I think at the very least they copyright the SD logo
and your use of it in advertising your product would
constitute an infringement. (I wonder if you could
advertise as "uses those little postage stamp size
memory cards commonly found in digital cameras" and
get around this :> )

I believe their (stated) goal is to ensure the "quality"
of compliant products is maintained so the market's
image of that technology isn't tarnished. (Of course,
I suspect they also have financial motives).

They could also want to protect IP as there are lots of
other compact portable media that they are competing
with for market share.

Personally, I'd use an inboard serial/data flash and
a USB slave interface. "Look like a mass storage device"
so you could just plug yourself into a PC "as a thumb
drive".

Or, implement a USB host interface and expect the
"data store" to be a mass storage device plugged *into*
your device. Depending on the size/complexity of the
product, this also opens other possibilities (e.g., you
could attach a USB wireless device and use telemetry to
deliver the data to a remote PC/collection device)

> What about a USB client port, and allow the use of USB thumb drives.

Huh? Do you mean a *host* port? I.e., to allow a thumb
drive to be plugged *into* the DATAC system? Or, do
you want the device to LOOK LIKE a "thumb drive"?

> Or, do ye have to forcibly join the USB association for that ...

"Resistance is futile"
From: Adrian C on 13 Apr 2010 12:51
On 13/04/2010 14:42, D Yuniskis wrote:

>> What about a USB client port, and allow the use of USB thumb drives.
>
> Huh? Do you mean a *host* port?

Er, Whoops - yeah, host.

--
Adrian C
From: D Yuniskis on 13 Apr 2010 13:19
Adrian C wrote:
> On 13/04/2010 14:42, D Yuniskis wrote:
>
>>> What about a USB client port, and allow the use of USB thumb drives.
>>
>> Huh? Do you mean a *host* port?
>
> Er, Whoops - yeah, host.

<grin> Keyboard failure! :>

I think the problem there is the number of product (MCU)
offerings with host support. :< Though I think it a
much "slicker" way of approaching the problem (i.e.,
it might be diffcult to carry the logger *to* the PC
if it was implemented as a "client/slave").

From: Silvar Beitel on 13 Apr 2010 14:58
On Apr 13, 5:41 am, Richard Rasker <spamt...(a)linetec.nl> wrote:

> - It would appear that I need a license from the SD Card Association if I
> want to build (and sell) anything containing an SD card host circuit (seehttp://www.sdcard.org/developers/join/licensing/"Host and Ancillary
> Products").

IIRC, using an SD card in SPI (single-bit serial MMC-like) mode does
not require a license. Only the 4-bit interface does.

Many PICs come with SPI controllers. The Microchip website has C code
for using an SD card as a USB bulk storage device - you can scarf the
SD control/read/write code from that.

--
Silvar Beitel
From: Frank-Christian Krügel on 13 Apr 2010 15:27
Am 13.04.2010 11:41, schrieb Richard Rasker:

> - It would appear that I need a license from the SD Card Association if I
> want to build (and sell) anything containing an SD card host circuit.

No, it doesn't. An SD card is an MMC card plus some kind of copy
procection (you are not going to use this) plus an additional 4 bit mode
(you most probably won't need it).

And every single SD or MMC card I've come across had an SPI mode
(although this seems to be optional). So it is basically an SPI storage
medium.

There are also Atmel Dataflash devices in MMC package:
http://www.atmel.com/atmel/acrobat/doc3257.pdf

--
Mit freundlichen Gr��en

Frank-Christian Kr�gel

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