Re: What does 'embedded' really mean?

Mike Noone wrote:

I was recently asked what 'embedded' really means, and I did not have a
good answer. Can anybody try to define it? I just am not sure as to a
concrete definition - I only can give examples of what is and what
isn't embedded.

-Mike

Well, you didn't say "embedded processor" so I assume you just can't find your dictionary :-).

Merriam-Webster online says:

Main Entry: em·bed
Variant(s): also im·bed /im-'bed/
Function: verb
Inflected Form(s): em·bed·ded also im·bed·ded; em·bed·ding also im·bed·ding
transitive verb
1 a : to enclose closely in or as if in a matrix <fossils embedded in stone> b : to make something an integral part of <the prejudices embedded in our language> c : to prepare (a microscopy specimen) for sectioning by infiltrating with and enclosing in a supporting substance
2 : to surround closely <a sweet pulp embeds the plum seed>
intransitive verb : to become embedded

IMOH this isn't too far off from what we mean when we say "embedded processor" or "embedded (computer) system".

I take the term "embedded processor" to mean any processor that's embedded into a system, the purpose of which is _not_ to present my processor in a pleasing aspect -- so while the Pentium that is helping me write this is in some sense embedded in the PC, it's not really embedded.

On the other hand, the MSP430 that's controlling the little levitating dingle-ball by my elbow* _is_ embedded, even though I can see through the clear plastic of the evaluation kit from TI to the processor.

Rather than finish the article (or book) that one could start this way, I'm just going to point out that I've seen a number of articles already written, most of which are probably available online with some digging.

* It's for a seminar I'm to be giving. I wanted a demo that was easy to build, cool to look at, and presented a challenging control problem. An inverted pendulum apparatus would look better from across a room (the dingle ball is only a 5/8" diameter), but would require more time in the metal shop. Controlling the temperature at the end of a bar of aluminum could certainly present some interesting challenges if you tried to do it fast, but it wouldn't offer much eye candy -- so I'm levitating a dingle ball.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html
.