On Sun, 19 Jun 2011 08:23:02 -0700, "Mr.CRC"
<crobcBOGUS@REMOVETHISsbcglobal.net> wrote:
>Jon Kirwan wrote:
><snip>
>
>> With the move towards large memory systems and 32-bit cpus
>> with FP and memory mgmt systems capable of runing Linux on a
>> chip, "embedded" has blurred to the point where you can't
>> tell the difference between a Microsoft MSDN developer, a
>> Linux guru, and an embedded micro coder, anymore.
>
>I can relate. I prefer bit banging, writing ISRs, that sort of thing.
>Though drivers can get a little tiresome. I figure if it doesn't need
>an oscilloscope to debug and verify, it's not my kind of "embedded."
>Perhaps I just prefer any excuse to use an oscilloscope!
I don't always require an oscilloscope or an MSO, but just
being threatened that I might need one is what makes it all
the more fun for me. Without at least the threat present,
it's certain to be boring.
>> The Windows CE coder seems to imagine they are doing embedded
>> work. So does the Linux coder. .NET can run embedded, in
>> fact, though anyone familiar with its details must realize
>> just how abstracted that environment is. Technically, yes, I
>> suppose it's true that porting code from a workstation to run
>> on an "embedded device" using .NET, for example, might still
>> meet some people's definitions. A lot of the discussions
>> here seem to be at that level now. Although I do .NET coding
>> and have my paid-up annual MSDN subscription, it's dull stuff
>> to me.
>
>I've cringed at the mere sight of ".NET" since its inception. I also
>hated Java since I first heard of it.
>
>We had a guy at work who thought "embedded" meant installing Linux on a
>SBC and programming it. It is "embedded" in a sense, but not quite the
>sense that it seems we would pretty much agree upon.
If you don't need to read datasheets, study peripheral
operation, read schematics, consider sensor/transducer
physics, do some laplace and partial fractions, look over
voltage thresholds and current limits, scan over compiler
output in assembly or machine code, set up that HP 54645D
with both 8-lead probes in hand just in case, and figure out
how to modify a linker control file, and all in the same
project, then it isn't embedded work... much.
>> I think of embedded to be about the skills required by us and
>> where they __differ__ from hosted environment development
>> skill sets. When a job requires familiarity more than just
>> one language and requires familiarity with how compilers
>> compile code, with assembly, with linker semantics and how to
>> modify their control files for some desired result, as well
>> as broad acquaintances with physics, numerical methods,
>> signal processing, optics, and certainly electronic design,
>> then we find more of these differences. When it requires
>> less of these differences from workstation development
>> skills, it is less about the "embedded" I know and love.
>>
>> Times are changing and the relative mix of skills found
>> amongst the embedded programmer body are shifting with the
>> capabilities being offered in todays tools. Entire operating
>> systems are ported over by people I do consider to be well
>> healed embedded programmers, but then just used lock-stock-
>> and-barrel by those who know little about what took place and
>> don't care to know and who just use the usual workstation
>> tools without knowing much difference, at all.
>>
>> That's a different thing to me. So I write less, today. I
>> haven't changed, but the audience has.
>
>Well I don't think the need for the more EE skill side of the trade will
>go away.
No, it grows. But the size of the pyramid of programmers
grows exponentially larger still. So it remains a dwindling
proportion of the conversation here despite the truth of what
you say.
>The changes probably amount to an overall improvement, since
>more people can access more technology and tools. That still a benefit
>even if some of them don't become master craftsmen. There's a place for
>developers with a cursory, high level undertanding. Think of Arduino
>and kinetic skulptors, for ex. If they can get something to just "work"
>then the world is a better place.
Agreed. I think this is very good, that computers have moved
from when I first worked on building my own. What I did
caused me to get written up in a large spread, with pictures,
in the local newspaper. It was _that_ unusual, I guess. I
don't know who ratted me out at the time. But the news
people showed up, one day, all the same. To have the case
where one can get a TI Launchpad send to you for $4.30, with
cables and a crystal and two cpus, and connectors and the
rest... no shipping charges... well, what can one say? It's
a great time, indeed!!
I am glad for all this. And I'm glad others might be
interested in them for any reason of their own, at all.
>At first I thought Arduino was stupid. "I can work with a bare AVR,
>what do I need that for?" I thought. Then I realized that if it makes
>more people play with microcontrollers, it is good. Now I'm even
>curious to check it out and see if it can spare me some time on my next
>8-bit project.
I just used a Launchpad to create a parallel port to USB
"printer device" that can be used as a parallel port printer
and it saves files automatically on the PC, instead. Had to
add a DB25, some wire and a few resistors and one cap, is
all. Oh, and a tiny piece of vector board. So yes, I get
your point here.
>>> Is that ARM families that can basically switch context in hardware, or
>>> some other device?
>>
>> Some other. For one example, the now "mature" or "older"
>> ADSP-21xx Family from Analog Devices is the example I had
>> coded that delta queue for.
>
>Oh that one. I was close to trying that out once. I actually would
>have preferred to use ADI processors for what I use the TI C2000 for,
>but at the time ADI had nothing like a "digital signal controller" with
>DSP speed and microcontroller peripherals. Blackfin has closed the gap
>a little, but it's still not what you'd pick to interface quadrature
>encoders and run MOSFET SMPS front-ends.
I used a TI 'C40 quite a while back, but when I was actively
also using the ADSP-21xx. I have to say it was night and day
between the two. I had TI support on the phone because the
hardware timing I was getting was 11 clocks for a cached bit
of code that according to their docs should have taken 7
clocks. They NEVER were able to explain the timing of the
bit of source code I sent them. Even after 3 weeks of their
working on it and comparing it to their docs about register
clashes and so on. Never did resolve the issue to my
satisfaction. By comparison, the ADSP-21xx worked _exactly_
as the docs said. Always. Exactly. Never a question about
them. The assembly (up to 3 instructions per cycle) was
nice, too.
>But TI assembly language is an ugly thing. It's not that bad if you can
>figure out the syntax and work with it enough to keep it memorized,
>which I haven't, because the docs are all language lawyer style when
>what is needed is more simple examples.
>
>With ADI, at least for SHARC which I looked at a bit, assembly is a breeze.
I know.
>>>> I've used this for an operating system with a
>>>> jitter-free guarantee on starting sleeping processes using
>>>> delta queues (where only one such process is allowed to sleep
>>>> on the same timed event.)
>>> <scratches head, wonders what a "delta queue" is>
>>>
>>> Hmm, looking at a few search results I sort of get it.
>>
>> It's a very simple, easy to operate, precision tool. I first
>> read about the idea from Douglas Comer's first book on XINU.
>
>Well I've a tidbit from you again. Thanks.
It's a book worth reading through. Very clear, very easy,
and it stimulates the imagination well.
>[edit]
>> I think I'd focus on an audio range device, as well. But I'm
>> pretty sure I'd just make it a toy and not something
>> professional. There is so much more "work" involved in
>> making something ready for others to use and although I find
>> some of that enjoyable, I don't find all of it to be so. And
>> I'd be looking more for my own hobbyist pleasure, self-test,
>> and education than anything else.
>
>Once it blurs into legalities, regulations, and injection molded die
>making, I start to run for cover. Probably better that I have a 9-5 job
>then.
Hehe.
>> I looked over some of what you write elsewhere and I wish I
>> had your experiences with lasers, too. Lots of potential fun
>> there, both for me and for students I like to teach at times.
>
>Yeah, well the lasers and my silly Chemistry degree cost me a lot of
>time that I sometimes wish I had spent on getting a proper EE degree.
I did as much chemistry as I wanted to do -- mostly
explosives as a kid. Mercury fulminate was my absolute fave
-- the reaction before the crystals settle out is a mad
scientist's exothermic, boiling, vaporous dream. And what
you get after, or better still after filtering and
precipitation with glacial acetic acid, was also a lot of fun
too. I did rocket fuels, explosives, fireworks, smoke bombs,
and pretty much anything "thermodynamic." Luckily also
learned enough extra to stay alive while doing that at home.
Still have picric acid, chlorates and perchlorates, and a few
other goodies laying about here. They used to ship that to
16 yr old kids, though the picric acid had to go by train. I
know. I was one and they Boulevard Labs in Chicago shipped
to me, regularly! Organics I got into a little. Enough to
get some of the basic terms down so that I could read and
draw things when asked, but nothing much more than that. I
know what a hydroxy ketone is defined as and I can draw out a
diagram for 1-Chloro-3,5-dinitro-4-hydroxybenzene if asked,
for example. But that's about it. Although there is logic
to organic naming, there is enough memorization of various
specialized words to bother me. Inorganics is easier in that
sense.
>> By the way, I've also got a lot of "stuff in drawers." And I
>> definitely get it about just goofing off with toys. Work is
>> work, but on my own I don't want the burden of having to do
>> all the extra stuff needed to productize. I'd rather play.
>>
>> Jon
>
>
>Have a good Father's Day, whether or not your a father!
Thanks. You too. And yes, I've 3. All in their mid 20's
now.
Jon