This debate topic reminds me of the story I heard about a reporter who was interviewing Louis Armstrong and asked him "What is Jazz?" His immortal reply: "Lady, if you don't know by now you'd better not mess with it."
I heard this one from the great Irish comic Dave Allen (paraphrased from memory):
One evening, a junior member of a club was listening to the club's oldest member tell of his great adventures hunting lions in Africa.
Oldest member (with gestures): I saw the lion ahead in the tall grass, up wind. I crawled through the grass on my hands and knees to get closer to get a better shot. Suddenly the lion was right in front of me! He stood up on his hind legs and went ROAAAAARRRRR!!!! [Oldest member waves hands wildly in air while roaring.]
Junior member (astonished): Good God, sir! What happened?
Oldest Member (suddenly pensive): I fouled me britches.
Junior member: I'm not surprised, sir.
Oldest member: I don't mean then -- I mean just now when I went ROAAAAARRRRR!!!!
Indeed it is difficult to define embedded system. Just like it is not easy to differentiate between CPU and MCU. Has 8051 ever considered as CPU? It has CPU core for sure. What about ARM? It is an embedded system. Oh! Really? I thought it is a CPU.
This debate is surely going to be interesting. Having spent about 32 years working on embedded systems, I think the whole wolrd is full of kind of embedded systems.
Apart from the systems based upon electronics or a combination of elelctronics and some kind of computing machine ( micro controller, micro processor , SOC , FPGA, and what not) there are many Systems which can be called as embedded, though they do not contain any kind of electronics.
Just take our body - the outer function is see, hear, eat, speak and so on but to do this so many systems are internally working in our body and are being controlled by a very complex nervous system and the central controller - the brain.
So a Human body can be termed as an Embedded system isn't it?
Too bad I will be busy friday during the time of the broadcast. (If it were an hour earlier like the normal friday chats then Max would get another Coconut.)
Regarding what is a "computer." When my niece was learning to talk and count at about 3 or 4 years of age, she came into my room and counted the monitors on the desk. She called out one two three for five 'puters." and asked me why I had so many. I said the boxes which contained AVRs, NxP and ST Arm processors also had computers in them, that there were actually over 100 computers in my room.
Personally I have never made a distinction between CPU chips and computers. Most of it is in the usage of the device. An example. The Atmel Tiny85 is similar to my first computer which was a S100 running the Sol Cuter Tape drive OS and Basic interpreter. I think the Tiny25 has more SRAM at 2K. Early Apple products were comparable. These machines could support 64K, few in the Homebrew computer club could afford much more than 4K, which was the main cost of early computing.
Dynamic refreshed memory changed this. With the trade off that Dynamic refresh was notoriously unreliable, so one spend time writing memory test code and rotating bit tests.
To the point here. If a mega328 (Arduino) has the same capability as say an Apple II. Could an Apple II be considered an embedded controller. I argue that yes it can. My first job was with an early Apple dealer. While I did sell Apple /// and Lisa computers, the bread and butter was the Apple II.
Our clients and customers would connect Apple IIs to a plotter, or a typesetting machine like a Ludlow, or even to a loom that wove cloth. Apple IIs were used as PLCs in the local industry replacing Relay logic. You could connect them to the security systems Radio Shack sold that used the house current to monitor the alarms. Woz Himself was the proponent of an early version of ioT, through his home automation proposals. Another Steve (Ciarcia the third Steve) started a magazine about the subject.
I say that if the device has GPIO or WPIO (Wireless Protocol Input Output -- I just made it up.) then it can be considered an embedded system.
Conversely what is not an 'Embedded' System? My own personal delineater is does it function like a glass teletype in front of an SQL database on big iron. Big iron is something like the old IBM machines like the 1130 or the 360/370 and the other 'Accounting and Tabulating machines.' Things that run offline and batch process data, with tabulated or printed results. Not embedded.
Put another way that hopefully will make sense to other EETs is that if it collects data it is probably an embedded cpu. If it does statistical or mathematical simulation then it is probably not embedded. If the device is used to do accounting it is either a calculator, or some sort of 'Bill and advertisement' spamming device and is anything but embedded.
Another touchstone is. If it has firmware, then it is probably embedded. If it has microcode and a user definable abstract instruction set, it is not embedded.
@Sheepdoll... "Too bad I will be busy friday during the time of the broadcast. (If it were an hour earlier like the normal friday chats then Max would get another Coconut.)".
If you offered him some Bacon he'd probably change it for you :-)
Ref the definitions. Mine (which a lot of people seem to subscribe to) is that if it is in a device whose primary function is not computing, that's embedded. So technically a PC running an X-ray machine (which you see quite often) qualifies as embedded. An Apple II used as a computer would not be, but if you got it to run an industrial plant it would be. But really we're talking MCU chips here. So in the survey, I said everything was an embedded system except a blade server and tablet computer. They are computers used as computers - everything else is running something else.
Lines up fairly closely with your definitions....but go ahead...shoot me down.... :-)
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...