AVR-Chat

Ummm... reading further on the SD assocation... I am possibly wrong on
this.

Their website descends into legalese on this issue. Elsewhere on the
site it says: "If your company is planning to manufacture or have
manufactured SD host products (eg. cell phones, cameras or computers) or
SD ancillary products (eg. adapters or SD I/O cards), your company is
required to:

   1. Join the SD Card Association and
   2. Enter into a Host/Ancillary Product License Agreement (HALA)**
with the SD Card Association and the SD-3C, LLC.  Latest Revision:
December 12, 2009"

but then underneath the ** says that the license is "available for the
convenience of licensees" and it's just a question of whether you
infringe their patents by including SD in the design. The patents seem
to mostly relate to the design of the card itself and implementation of
the SD specifications. 

According to google this question has been discussed in various forums -
and opinion there seems to be that if you use SPI mode to address the
card, this is a "legacy" addressing mode which is not covered by their
patents. SPI is the method used by all the software I have ever come
across.


There's no question that you do need to join their association to use
the SD logo.

-- 
Tim Mitchell