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Sci.Electronics.Basics -> Which uController to learn?
There are 124 messages in this thread.
You are currently looking at messages 120 to 124.
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Author: jasenDate: 07:34 25-03-07
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On 2007-03-24, Lionel <usenet@imagenoir.com> wrote:
> On 24 Mar 2007 09:07:41 GMT, jasen <jasen@free.net.nz> wrote:
>
>>On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
>>> jasen wrote:
>>>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>>>
>>> Speak for yourself. Since when is A/D resolution not important for an 8
>>> bitter?
>>
>>how often is 10 bits too few ?
>
> Quite often. Photography & audio work, just for two popular examples.
you want to do serious audio *1 or imaging *2 on a 20MIPS 8-bitter ?
*1 for toys, or telephony, 8 bits are enough
*2 I can't see 10 bits needed for an exposure meter,
at low speeds switched gain is an option.
--
Bye.
Jasen
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Author: krwDate: 10:42 25-03-07
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In article <9fac0393nnc4fvfdn4adjaqn1vbni30aa9@4ax.com>,
usenet@imagenoir.com says...
> On Sat, 24 Mar 2007 19:32:44 -0400, krw <krw@att.bizzzz> wrote:
>
> >In article <46059f7e$0$3748$ba620dc5@text.nova.planet.nl>,
> >burrynulnulfour@ppllaanneett.nnlll says...
> >> jasen wrote:
> >> > On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
> >> >> jasen wrote:
> >> >>> On 2007-03-16, Anthony Fremont <spam-not@nowhere.com>
wrote:
> >> >>>> TT_Man wrote:
> >> >>>>>> As you said, PIC is king and it is for a reason,
they work.
> >> >>>>>>
> >> >>>>> Only if you can get to grips with the appalling op
code set..... OK
> >> >>>>> if you can program in C , I suppose.I can't/won't
> >> >>>> I only do assembler on the PIC too. What's wrong with
the op-code
> >> >>>> set? It's RISC,
> >> >>> no it's not, it has too few registers to qualify.
> >> >> By whose definition?
> >> >
> >> > Pretty much everyones (with the exception of the PIC fans).
> >> >
> >> > google "what is risc" sometime.
> >> >
> >> >
> >> >
> >> What do you not understand about
> >> "Reduced Instruction Set Computer"?
> >
> >The term is "Reduce Instruction Set Complexity".
>
> No, it isn't:
> <http://en.wikipedia.org/wiki/RISC>;
>
>
> >> (A computer with a reduced instruction set???)
> >
> >No, it's a computer with a set of less complex instructions. The set
> >can still be quite large and complex (e.g. PowerPC).
> >
> >> A computer with about 30 instructions can be called
> >> a risc computer,as compared to the x86 group with about 500.
> >
> >Not necessarily. If it has memory reference arithmetic instructions
> >(e.g. ADD R,<memory>) it is NOT a RISC processor.
> >
> >> Now if you want to claim that name for something else,
> >> you better explain that, because I think a lot of people
> >> dont agree with you.
> >
> >Anyone with a passing familiarity with computer architecture will.
>
> I have more than a "passing familiarity" with computer architecture
> (nearly 30 years, so far), & I don't agree with you.
>
Funny, the people who invented the term (and the first example
hardware) do. I tend to defer to them.
--
Keith
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Author: LionelDate: 12:18 25-03-07
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On 25 Mar 2007 11:34:59 GMT, jasen <jasen@free.net.nz> wrote:
>On 2007-03-24, Lionel <usenet@imagenoir.com> wrote:
>> On 24 Mar 2007 09:07:41 GMT, jasen <jasen@free.net.nz> wrote:
>>
>>>On 2007-03-23, Anthony Fremont <spam-not@nowhere.com> wrote:
>>>> jasen wrote:
>
>>>>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>>>>
>>>> Speak for yourself. Since when is A/D resolution not important for an
8
>>>> bitter?
>>>
>>>how often is 10 bits too few ?
>>
>> Quite often. Photography & audio work, just for two popular examples.
>
>you want to do serious audio *1 or imaging *2 on a 20MIPS 8-bitter ?
Hell no! I was speaking generally. ;^)
> *1 for toys, or telephony, 8 bits are enough
>
> *2 I can't see 10 bits needed for an exposure meter,
Well, light meters for photographics work on a Log2 scale, so it
requires more ADC resolution than you might expect at first glance.
That said, a good sample & hold in front of a dual-slope converter
would be perfectly suitable for most such purposes.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
\|/ \|/ Perna condita delenda est
---^----^---------------------------------------------------------------
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Author: LionelDate: 22:40 25-03-07
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On Sat, 24 Mar 2007 14:39:09 GMT, Lostgallifreyan <no-one@nowhere.net>
wrote:
>Lionel <usenet@imagenoir.com> wrote in
>news:0g8a039nv97085vme4997faf4nhuko1uf0@4ax.com:
>
>>>>> It's an 8-bit microcontroller it doesn't need that extra stuff ...
>>>>
>>>> Speak for yourself. Since when is A/D resolution not important for
>>>> an 8 bitter?
>>>
>>>how often is 10 bits too few ?
>>
>> Quite often. Photography & audio work, just for two popular examples.
>>
>
>Agreed. SOme tasks like laser scanning might call for a small dedicated
>controller, and you'd certainly want 16 bits there, especially if colour
>mixing was needed.
>
>Even a small task like lin/log conversion, which many on Usenet advise me
>was best solved by code, needs to use 16 bits for accuracy over a decent
>range.
Indeed.
> Unless more tiny micros are made with 16 bit ADC and DAC on board,
>people will always be agonising over expensive analog computation IC's. Far
>better that we have a small number of cheap standard parts we can learn to
>code for.
ADCs & DACs are sold as modules for exactly this reason.
> If I knew I could have this, I'd put more effort into learning
>it. I don't want to do it with a 40 pin device that needs a diploma to
>learn either
Mate, that's electronics for you. If you need those sorts of features,
you need to either pay someone else the big bucks to make you one, or
study long enough to figure out how to make one yourself. (At which
time you'll discover why the first option is so expensive.)
>, I want to do it with a 4 pin IC and some very simple high
>level language.
I'm tempted to make a joke here about wanting a pony. ;^)
>
>The way things are now, even real experts have argued and floundered over
>what best to advise. If more small micros had 16 bit analog I/O built in,
>people like me wouldn't even have to ask.
16 bit ADCs (& even DACs) are expensive & difficult to implement at
the best of times. Trying to put them on a microcontroller would be
just about impossible to do at a sane price. (Plus it'd require
multiple, ultra-low-noise, power lines & complex shielding.)
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
\|/ \|/ Perna condita delenda est
---^----^---------------------------------------------------------------
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