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AVR weather station for newbie...

AVR weather station for newbie...

2006-01-09 by Kong

hi all,

foa, newbie here, so pls go easy, if you could ;-)
i'm looking at building a weather station. google tells me there are a 
few out there based on PIC. someone suggested AVR atmega169 but i'm put 
off by its mlf packaging.
i'll need adc, lcd, push buttons, ram/flash to store data history, 
serial to PC later. it looks like pic16f877 should be the trick for me 
but i figure i should give avr a chance. so i'm here looking at the 
whys/why-nots of using AVR to build my weather station.
ok. flame away.

cheers
-ls kong

Re: [AVR-Chat] AVR weather station for newbie...

2006-01-09 by Zack Widup

On Mon, 9 Jan 2006, Kong wrote:

> 
> hi all,
> 
> foa, newbie here, so pls go easy, if you could ;-)
> i'm looking at building a weather station. google tells me there are a
> few out there based on PIC. someone suggested AVR atmega169 but i'm put
> off by its mlf packaging.
> i'll need adc, lcd, push buttons, ram/flash to store data history,
> serial to PC later. it looks like pic16f877 should be the trick for me
> but i figure i should give avr a chance. so i'm here looking at the
> whys/why-nots of using AVR to build my weather station.
> ok. flame away.
> 
> cheers
> -ls kong
> 

The atmega16 is not all that different than the PIC 16F877.  It's in the 
same package.  You will probably find the program a little simpler with 
the AVR, as I find the ADC, timers, etc. simpler to program in the AVR's 
(less setup directives). Also, the 32 working registers in the AVR's make 
things a lot simpler than the single W register in the PIC's.

Zack

Re: AVR weather station for newbie...

2006-01-09 by Kong

tom,

i'm half way to being converted! by nothing more than the quality of
your post alone! ;-)

the last time i wrote anything substantial (>10 years ago), i went for
delphi instead of VB or VC++, does that make me a PIC or an AVR person?  

now if, i say if, i decide to go with AVR. which chip and tools would
you recommend i start with? assuming that i am not going to stop with
one project...
is the atmega169 a good chip to start with?
is the ATAVRBFLY (butterfly?) a worthy toy to learn with?
should i get the stk500 or are the better alternatives?

could you recommend some good sites/links (beside this one of course)
for me to read up on?

thanks.

--kong


--- In AVR-Chat@yahoogroups.com, Thomas Keller <tkeller1@n...> wrote:
>
> Kong wrote:
> 
> >hi all,
> >foa, newbie here, so pls go easy, if you could ;-)
> >i'm looking at building a weather station. google tells me there are a 
> >few out there based on PIC. someone suggested AVR atmega169 but i'm
put 
> >off by its mlf packaging.
> >i'll need adc, lcd, push buttons, ram/flash to store data history, 
> >serial to PC later. it looks like pic16f877 should be the trick for me 
> >but i figure i should give avr a chance. so i'm here looking at the 
> >whys/why-nots of using AVR to build my weather station.
> >ok. flame away.
> >cheers
> >-ls kong
> >  
> >
> Kong,
> 
>   There is nothing inherently "wrong" ( or "right," for that matter)in 
> choosing a PIC over an AVR, or vice versa.  Among the denizens of this 
> particular mailing list you will, of course, find most promoting and 
> advocating the use of the AVR family (odd thing, that).
> 
>   My take on the ifferences is as follows (not necessarily in any order 
> of importance):
> 
> 1)  efficiency.  The PIC line is a four phase clocking architecture, 
> which means that each instructiins take at LEAST 4 clock cycles to 
> complete.  The AVR is a single-phase clocling architecture.  The 
> majority of instructions cvomplete in a single clock cycle.  This means 
> that, all other things (fabrication technology, etc.) being equal, the 
> PIC will requuire more power per instruciton to get the job done.
> 
> 2) computing architecture.  The PIC has what I personally consider
to be 
> a very clumbsy architectural design.  The registerset usage is not 
> orthogonal,  memroy addressing isn't linear, etc.  While PICs are 
> imminently programmable (witness the massive nuymber of PICs in use,
and 
> the hughe number of hobbyist projects based on PICs), these 
> architecturalk detailsmake them more difficult to program.  Some people 
> seem to see the very small PIC instruction set as a plus.  I do not.
> 
> 3) While there are a large number of different AVR processors avaiable, 
> the PIC line swamps the AVR line in terms of numbers of family members. 
> Moreover,  there can be fairly substantial differences in the way
things 
> are done from one PIC family to another.  Forthe most part, AVRs are 
> AVRs. Within reasonable limits, what works on one AVR will work on 
> another (exluding, of course, the use of hardware resources such as 
> additional peripheral features in the larger, more powerful familky 
> members).
> 
> 4)  While some newer PIC support ISP (In System Programming) without 
> specialized expensive hardware and software, many (most?) do not.  
> Worse, the programming hardware that works for one PIC family may or
may 
> not work for the next more powerful family up the line, which can be a 
> real headache if you discover that theprocessor you chose is lacking in 
> some speed or hardware resource you need, and overlooked in your
initial 
> selection.
> 
> 5)   **ALL** of the software you will need to develop a project on te 
> AVR is freely available, including some stellar quality software 
> directly from Atmel.  For the PIC line, you'll pretty muvch be limitewd 
> to what you can purchase (though not exclusively).  I am not aware
of an 
> implmentation, for example, of gcc for the PIC, but it is out there for 
> the AVR (primary reason for this, I suspect,is the complexity of 
> supporting a wide range of PIC processors, with the massively differing 
> hardware and software requirements).
> 
> 6) back to the programming issiue a moment:  for about $5 (retail cost 
> of components) you can easily construct a programming dongle usable
with 
> ANY AVR processor.  A DB-25M connector, 5 strands of wire, and a means 
> of connecting the wires at the other end to the AVR (I saw oe guy who 
> useed mini-alligator clips - not something I would recommend,
however).  
Show quoted textHide quoted text
> I don't know of anyone who can put together a PIC programming platform 
> for $5.
> 
> 7)  Though I haven't searched exhaustively for PIC support, my 
> experience in searching for AVR support onthe World Wide Web has been 
> p[leasantand highly productive.  I wuld be verysurprised to see the 
> level and scope of free web basedsupport for the PIC that I have found 
> for the AVR family.
> 
> 8)  IN terms of raw speed,  AVRs are availablew, in general, up to 20 
> MIPs in performance.  PICs (with the exception of the dsPIC line) are 
> restricted to 10 MIPs, max.  (there is one AVR that offers 48 MIPs 
> performance, but it is a special unit, and I don't consider it fair to 
> include it in this comparison(the AT76USB370, 48 Mhz clock, up to 12 
> Mbps USB 2.0).
> 
> 9)  Finally, and most importantly:  if you go with PIC, you  will not 
> enjoy the benefits and pleasures of dealing with all of us, here in AVR 
> land!!!!
> 
> tom
>

Re: [AVR-Chat] AVR weather station for newbie...

2006-01-09 by Thomas Keller

Kong wrote:

>hi all,
>foa, newbie here, so pls go easy, if you could ;-)
>i'm looking at building a weather station. google tells me there are a 
>few out there based on PIC. someone suggested AVR atmega169 but i'm put 
>off by its mlf packaging.
>i'll need adc, lcd, push buttons, ram/flash to store data history, 
>serial to PC later. it looks like pic16f877 should be the trick for me 
>but i figure i should give avr a chance. so i'm here looking at the 
>whys/why-nots of using AVR to build my weather station.
>ok. flame away.
>cheers
>-ls kong
>  
>
Kong,

  There is nothing inherently "wrong" ( or "right," for that matter)in 
choosing a PIC over an AVR, or vice versa.  Among the denizens of this 
particular mailing list you will, of course, find most promoting and 
advocating the use of the AVR family (odd thing, that).

  My take on the ifferences is as follows (not necessarily in any order 
of importance):

1)  efficiency.  The PIC line is a four phase clocking architecture, 
which means that each instructiins take at LEAST 4 clock cycles to 
complete.  The AVR is a single-phase clocling architecture.  The 
majority of instructions cvomplete in a single clock cycle.  This means 
that, all other things (fabrication technology, etc.) being equal, the 
PIC will requuire more power per instruciton to get the job done.

2) computing architecture.  The PIC has what I personally consider to be 
a very clumbsy architectural design.  The registerset usage is not 
orthogonal,  memroy addressing isn't linear, etc.  While PICs are 
imminently programmable (witness the massive nuymber of PICs in use, and 
the hughe number of hobbyist projects based on PICs), these 
architecturalk detailsmake them more difficult to program.  Some people 
seem to see the very small PIC instruction set as a plus.  I do not.

3) While there are a large number of different AVR processors avaiable, 
the PIC line swamps the AVR line in terms of numbers of family members. 
Moreover,  there can be fairly substantial differences in the way things 
are done from one PIC family to another.  Forthe most part, AVRs are 
AVRs. Within reasonable limits, what works on one AVR will work on 
another (exluding, of course, the use of hardware resources such as 
additional peripheral features in the larger, more powerful familky 
members).

4)  While some newer PIC support ISP (In System Programming) without 
specialized expensive hardware and software, many (most?) do not.  
Worse, the programming hardware that works for one PIC family may or may 
not work for the next more powerful family up the line, which can be a 
real headache if you discover that theprocessor you chose is lacking in 
some speed or hardware resource you need, and overlooked in your initial 
selection.

5)   **ALL** of the software you will need to develop a project on te 
AVR is freely available, including some stellar quality software 
directly from Atmel.  For the PIC line, you'll pretty muvch be limitewd 
to what you can purchase (though not exclusively).  I am not aware of an 
implmentation, for example, of gcc for the PIC, but it is out there for 
the AVR (primary reason for this, I suspect,is the complexity of 
supporting a wide range of PIC processors, with the massively differing 
hardware and software requirements).

6) back to the programming issiue a moment:  for about $5 (retail cost 
of components) you can easily construct a programming dongle usable with 
ANY AVR processor.  A DB-25M connector, 5 strands of wire, and a means 
of connecting the wires at the other end to the AVR (I saw oe guy who 
useed mini-alligator clips - not something I would recommend, however).  
I don't know of anyone who can put together a PIC programming platform 
for $5.

7)  Though I haven't searched exhaustively for PIC support, my 
experience in searching for AVR support onthe World Wide Web has been 
p[leasantand highly productive.  I wuld be verysurprised to see the 
level and scope of free web basedsupport for the PIC that I have found 
for the AVR family.

8)  IN terms of raw speed,  AVRs are availablew, in general, up to 20 
MIPs in performance.  PICs (with the exception of the dsPIC line) are 
restricted to 10 MIPs, max.  (there is one AVR that offers 48 MIPs 
performance, but it is a special unit, and I don't consider it fair to 
include it in this comparison(the AT76USB370, 48 Mhz clock, up to 12 
Mbps USB 2.0).

9)  Finally, and most importantly:  if you go with PIC, you  will not 
enjoy the benefits and pleasures of dealing with all of us, here in AVR 
land!!!!

tom

Re: [AVR-Chat] AVR weather station for newbie...

2006-01-09 by Thomas Keller

Kong wrote:

>hi all,
>
>foa, newbie here, so pls go easy, if you could ;-)
>i'm looking at building a weather station. google tells me there are a 
>few out there based on PIC. someone suggested AVR atmega169 but i'm put 
>off by its mlf packaging.
>i'll need adc, lcd, push buttons, ram/flash to store data history, 
>serial to PC later. it looks like pic16f877 should be the trick for me 
>but i figure i should give avr a chance. so i'm here looking at the 
>whys/why-nots of using AVR to build my weather station.
>ok. flame away.
>  
>
   An additonal note, not related to the AVR vs PIC issue:


  In an older issue of Circuit Cellar, Ink, there is a feature on 
building your own ultrasonic anemometer.  realtively simple, at least 
from the hardware perspective:  foiur small towers, on the corerns of a 
small platofrm, each with an ultrasonic transducer mouted at the top, 
each transducer pointed tooward the diagonally opposite corent, and 
mounted to that the corners are in the NW/SE, NE/SW directions.  A 
lkittle software magic measuring temprature and changes in propagation 
delay of utlrsaonic burts between the corners, and viola!  Instant 
ultrasonic anemometer.  Cool, eh?  I'll look up the specific cite for 
you guys and post it later, but it is availabelonlineat 
www.circuitcellar.com (I am pretty sure of the URL).  Publishedin 1998 
or so. (original proejct based on a PIC and a mini-computer)
tom

Re: [AVR-Chat] Re: AVR weather station for newbie...

2006-01-09 by James Hatley

----- Original Message ----- 
Show quoted textHide quoted text
From: "Kong" <kong.ls@gmail.com>
To: <AVR-Chat@yahoogroups.com>
Sent: Monday, January 09, 2006 8:48 AM
Subject: [AVR-Chat] Re: AVR weather station for newbie...


>
> tom,
>
> i'm half way to being converted! by nothing more than the quality of
> your post alone! ;-)
>
> the last time i wrote anything substantial (>10 years ago), i went for
> delphi instead of VB or VC++, does that make me a PIC or an AVR person?
>
> now if, i say if, i decide to go with AVR. which chip and tools would
> you recommend i start with? assuming that i am not going to stop with
> one project...
> is the atmega169 a good chip to start with?
> is the ATAVRBFLY (butterfly?) a worthy toy to learn with?
> should i get the stk500 or are the better alternatives?
>
> could you recommend some good sites/links (beside this one of course)
> for me to read up on?
>
> thanks.
>
> --kong
>
>
<<< snip >>>

Hello Kong,

I believe that the STK500 is a very good bargain and it even comes with a
chip to get you started. Not sure what they are sending these days but for
$79 ( Digikey, All-American, etc. ) it is a good start and I'm sure if you
wanted you could make a weather station out of it. But it may be better to
use it get your feet wet and build what you really want went you've done
some experimenting.

Some easy google searches will find other AVR prototype boards ... there are
many and many good ones.

Here I use the Imagecraft compiler for my projects and I strongly recommend
it. The 4k version is without any charges and you can get started, just
download the demo version and get go. If you need larger the standard
version is quite inexpensive for such a marvelous C compiler. If you just
need assembly then AVR Studio has all you would need I believe.

The Atmel site has a lot of reading. Search for articles in google there are
many. And it seems I remember a weather station article on the Maxim/Dallas
web site somewhere. Lots of luck and learning.

Jim

Re: AVR weather station for newbie...

2006-01-10 by Kong

--- In AVR-Chat@yahoogroups.com, Thomas Keller <tkeller1@n...> wrote:
>   In an older issue of Circuit Cellar, Ink, there is a feature on 
> building your own ultrasonic anemometer.  

thanks again tom. found it as a featured article.
there's also a wireless weather station based on pic16f873...
http://www.circuitcellar.com/

-kong

Re: [AVR-Chat] Re: AVR weather station for newbie...

2006-01-10 by Ralph Hilton

On Mon, 09 Jan 2006 16:48:24 -0000 you wrote:

>
>tom,
>
>i'm half way to being converted! by nothing more than the quality of
>your post alone! ;-)
>
>the last time i wrote anything substantial (>10 years ago), i went for
>delphi instead of VB or VC++, does that make me a PIC or an AVR person?  
>
>now if, i say if, i decide to go with AVR. which chip and tools would
>you recommend i start with? assuming that i am not going to stop with
>one project...
>is the atmega169 a good chip to start with?
>is the ATAVRBFLY (butterfly?) a worthy toy to learn with?
>should i get the stk500 or are the better alternatives?
>
>could you recommend some good sites/links (beside this one of course)
>for me to read up on?

http://www.prllc.com/productcart/pc/viewPrd.asp?idcategory=6&idproduct=12

Chapter 5, Project Development
This chapter focuses on the orderly development of a project using microcontrollers.  A
complete wireless indoor/outdoor weather station is developed in its entirety to
illustrate the process.
--
Ralph Hilton
http://www.ralphhilton.org
C-Meter: http://www.cmeter.org
FZAOINT http://www.fzaoint.net

Re: AVR weather station for newbie...

2006-01-10 by Kong

--- In AVR-Chat@yahoogroups.com, Ralph Hilton <ralph@r...> wrote:
>
http://www.prllc.com/productcart/pc/viewPrd.asp?idcategory=6&idproduct=12
> 
> Chapter 5, Project Development
> This chapter focuses on the orderly development of a project using
microcontrollers.  A
> complete wireless indoor/outdoor weather station is developed in its
entirety to
> illustrate the process.
> --

thanks ralph. but is that an expensive book or what? perhaps it's
targeting people in the embedded system industry and not for hobbyists...

Re: AVR weather station for newbie...

2006-01-10 by Kong

iiuc, this problem is not particular to electronic outdoor temperature
sensing. the same can be said about mecury thermometer placed outdoor.
electronics only bring the readings indoor and perhaps into a pc, then
even on to the internet. also, sometime it's not only the absolute
readings that're of interest but also the trends, from one day to
another, from one month to another and if it survives that long, from
one year to another...

--kong

--- In AVR-Chat@yahoogroups.com, Thomas Keller <tkeller1@n...> wrote:
>
>   One thing that has always bothered me about electronic weather
station 
> design:
>    How do you normalizee temperarture readings (perhaps I am using the 
> wrong term here).?
> 
>    If you place your temperature sensor diredtly in the sunlight, it 
> will likely register a higher reading thanthe actual ambient ait 
> temperature, due to direct heating by the IR of the sun.  if you
enclose 
> it, you have the heating of the enclosure to correct for.
> 
> 
>   Enclose it in something highlky reflective? (e.g., a piece of white 
> ABS pipe, with plenty of airflow thhrough it, or a polished aluiminum 
> enclosure with plenty of airflow?)   Simply place it under an "awning" 
> laid out to insure that no sunlight impinges directly upon the
sensor?   
> How far fromthe inner surface of this awning would thesensor need to
be, 
> not to pick up erroneous readings due to radiation of heat fromthe
awning?
Show quoted textHide quoted text
> 
> *heh*  sometimes my mind asks too many quesitons, eh?
> 
> tom
>

Re: [AVR-Chat] Re: AVR weather station for newbie...

2006-01-10 by Thomas Keller

Kong wrote:

>tom,
>
>i'm half way to being converted! by nothing more than the quality of
>your post alone! ;-)
>  
>

>*blush*
>  
>

>the last time i wrote anything substantial (>10 years ago), i went for
>delphi instead of VB or VC++, does that make me a PIC or an AVR person?  
>
>  
>

   I don't know that it is relevant at all.  While I never chose to use 
Delphi for anything, from wqhat I have read and heard over the years, it 
was a quite servicable applicaiton development platform.  Frankly (being 
an anti_Micey$lu$h bigot) I'm more imnpressed with you choosing s 
non-Mickey$lu$h product.  I have never liked the "Visual" product line.

>now if, i say if, i decide to go with AVR. which chip and tools would
>you recommend i start with? assuming that i am not going to stop with
>one project...
>is the atmega169 a good chip to start with?
>is the ATAVRBFLY (butterfly?) a worthy toy to learn with?
>  
>
   *WHOA*   that's sort of like asking "What's the best graphics card" 
or "Who makes the best computer?" *heh*

   The ATMEGA169 appears to be a very powerful chip.  I haven't studieid 
it in detail, but IIRC it includes direct LCD support, right?  If that 
is correct, and if you plan on workign with many LCDs, that might be a 
way to go.  The Biutterly is an amazing, low cost device, capable of 
increidble feats, given its cost.   Quite limited in overall 
capabilities, but if you're ona tight budget, it might be an exceellent 
first choice.

>should i get the stk500 or are the better alternatives?
>
>  
>
  Well.   An interesting question.   The STK-500 is certainly among the 
most reasonably priced vendor supplied development systems I have seen 
on the markert.  $79(US) is not a high price at all.  With one, in my 
not so humble opinion, serious designflaw, it is a fairly well designed 
piece of gear, at a reasonable price (and I wouldn't let that single 
perceivced design flaw stop me from purchsasing one...ikndeed, had I the 
$$$ to spasre, one would be sitting here on my deslk at this very moment).

  My complaint is the number of "add-on" moduels needed to support the 
entire range of AVR family processors.  By the time you have purchsased 
the entire set of "expansion" modules, you have over $700 invested.  It 
is now starting to be priced more like other maker'ssystems. )-:  In 
particulkar, I am distressedby theri choice of support for DIP packaged 
processors.

  There is no need for there to be a requirement for additional 
ecxapnasion kits toi support *ANY* size of DIP processor.  I canpurchase 
a 48 pin DIP zero insertion force socket from Digikey for $25 (qty 1) 
which will accept and support anything from a 6 pin DIP through a 40 pin 
DIP, ineither .3 or.6" widths.  A rational and inexpesnive means of 
supporting a very wide range of processors.   I am disappointed thsat 
the engineers at Atmel didn't make such a choice. In general, I find 
their engineering innovative, intelligent and impressive.

   But then, one could also argue that I am looking a gift horse in the 
mouth.   In my opinion, Atmel is by far themost hobby friendly vendor of 
microcontorller and related chips in the marketplace today.  Their 
support and their incredibly generous sample policies make using Atmel 
processors for hobby projects a pure joy, at least for me.

(to be fair, my understnading is that Micorchip also has a faily lenient 
sampling policy, though, having no use for their products, I haven't 
checked that our for myself)  Also to be fair, MicorChip manufactures a 
wide range of non-processor products, mostly in support of embedded 
processor development.  Signal converters, op amps, sensors, etc., etc., 
and some with very impressive specifications.   WHile I may disparage 
the PIC line (mostly because the architecture is rooted inthe 1970s), 
MiceroChip is a quality, profesisonal company, provbiding high quality, 
well designed components to the industry.,  I can get a little carried 
away with my technical criticisms, sometimes.

>could you recommend some good sites/links (beside this one of course)
>for me to read up on?
>  
>
   Googlefor AVR.  There are HUNDREDS of web sites out there.  Watch at 
the bottom of the pages you visit for the AVR WEb Ring, asnd join it.   
www.avrfreaks.net is a superb (if sometimes chaotic) source of AVR and 
AVR related informaiton and resources.   And don't be a stranger to 
Atmel's website.  I have downloaded virtualkly every AVR related 
document they offer.  In general, their Applications Notesd are well 
written and highly informative.  Likewise their Data Sheets,  (don't 
underestimate the educaitonal value of data sheets, by the by.  I always 
read thme cover to cover, sewveral times, when starting with a new 
device).  My only minnor quibble is that the company's German roots show 
through sometimes.  Atmel's publicaitons have been my first encounter 
with "German English" (similar in principal to the Japanese English we 
often see in instructions or printed matter in products made in Japan, 
and, I suspect, for similar reasons). Sometimes the syntax of a sentence 
can really throw you on first reading.  Indeed, sometimes the syntax 
leads to amusing reading.

  Never the less, the quality and literacy of their publicaitons is VERY 
high.  (I will disgree again here toward MicroChip.  Despite the fact 
that MicroChip[ is a "native" American company, where Atmel is a German 
company, I find the quality and iun particular the :"literateness" of 
their publication to be inferior to those of Atmel, and frnakly, I find 
it difficult to locate the informaiton I am seeking in most of their 
docuemnts.  ut that could just be me)

   As for whicxh chip to start with, I think the better question for you 
would be:  what sort of project do I wish to start with?  Select the AVR 
which is appropriate to your project. If that is an 8 pin ATTINY11, so 
be it.  If it is a 144 pin ATMEGA, so be it.  It's just more pins, which 
means more I/O functions.  it's not  not more "difficult".  If you can 
successfully implement a project using the smallest ATTINY11, you 
canjust as well successfulky implememntn a project using the largest, 
most powerful ATMEGA processor.

   BTW, take a look a t the newest memebers of the ATTINY family, the 
ATTINY 24/44/84.  New pavckage outline for Atmel:  14 pin DIP (also 
soic, and some other SMT formats).  Most intresting.  The ATTINY84 has 4 
K of Flash, 512 bytes of SRAM, 512 bytes of EEPROM, 8 channels DAC, and 
an onchip temperaturesensor, and costs, IIRC, $1.14 qty 1.  20Mhz 
maximum clock rate, BTW.

  I **DO** wish Atmel would recognize the need for faster AVRs.  We 
know, form the AT76USB370 that they can make AVRs that run at higher 
speeds (48 Mhz clock, offerint 48 MIPs of performance).  I cannot fathom 
why they don';t introduce soem 40 to 60 Mhz chips.  i am quite sure 
theye's a market for them (besides which, it isn;t all that difficukt 
oir expensive to push 20 Mhz designs to 40 or 80 Mhz, these days.  Just 
scale down the geometry a bit, mostly).

  Well, I'm starting to ramble now.....bye


tom

AVR overclocking question

2006-01-10 by Thomas Keller

So...has anyone here overclocked AVR chips?  How successfully?  Hpow far?

   I note that some fothe Atmel data sheet charts show performance at up 
to 24 Mhz, which is 25% above the rated 20 Mhz maximum clock.

   I also note that Atmel is very specific about not pushing the clcok 
speedfor the EEPROM over certain fairly conservative limits.  I am 
guessing,   based on their literature, that the EEPROM circuits are the 
most sensitive to excessive clock speeds (whihc kind of makes sense, 
thinking about how EEPROMS are written).

  In any case, any experience?

tom

wireless stuff

2006-01-10 by Thomas Keller

Kong wrote:

>there's also a wireless weather station based on pic16f873...
>http://www.circuitcellar.com/
>  
>
  Speakjing of wireless, Atmel isn't suppoting it YET, though I have 
little doubt that they will come on board eventually:


  Check out Zigbeee wireless mesh networking.   IEEE 802.15.4 standard 
for a 2.4 Ghz sprread specxtrum mesh network protocol which offers 
self-forming, self-healing network deployment, and operability withoiut 
interference inthe vicinity of other wiresless 2.4 Ghz services such as 
802.11x and Bliuetooth (no intereference ineither direction, accoirding 
to the specs)

  A quick overview:   2.4 Ghz, 250 Kbps, originally designed to support 
wireless sensor networks.  In the  base conficuration, it offers 75 
meters range, node to node.  Since the network is a mesh, so long as no 
node is any further than75 meters from any other node, the network 
maintains integrity, regardlessof overall distance from "first node" 
to:"last node."  You can alos use RF power amplifiers and hihger end 
antennae to achieve up to just shy of 1 mile of range.,

   All Zigbee capable components I have seen so far are completely 
self-contained,.  Most are embedded on a 16 or 32 bit processor, but 
have saparate ROM-based Zigbee networking stacks included, so all you do 
fromthe processor is push a few values into dsome setup registers, and 
start passing the network data.   Zigbee protocolhandlesall addressing 
issue and so on, so if a message comes acorss the network for yoiuyr 
processoir,m it gets an interrupt teling it so, with no other overhead 
inyour softeware at all.

  There are also add-on Zigbee "processors" which can be hung off the 
side of your existing uP.

    Zigbeee is very inexpensive.  One vendor will soon (1Q 06, 
allegedly) be shipping a 12.5 Mhz,m 16 bit processor with embedded 
Zigbee hardware/firmware.  Included are hardware encryption 
accelerator,m hardware based random number support,  a wide range of  
typical embedded processor peripherals, all for about US$5 qty 1.   
Believe it or not.

  There are more and more vendors jumping on the Zigbee bandwagon. My 
understanding is that Zigbee is huge in Europe (though i have no 
specific informaiton on that).

   Jennic is one vendor offering both embedded processors enabled for 
Zigbee, as well as Zigbee addons.  www.Jennic.com, IIRC.


Tom

Re: [AVR-Chat] Re: AVR weather station for newbie...

2006-01-10 by Thomas Keller

One thing that has always bothered me about electronic weather station 
design:


   How do you normalizee temperarture readings (perhaps I am using the 
wrong term here).?

   If you place your temperature sensor diredtly in the sunlight, it 
will likely register a higher reading thanthe actual ambient ait 
temperature, due to direct heating by the IR of the sun.  if you enclose 
it, you have the heating of the enclosure to correct for.


  Enclose it in something highlky reflective? (e.g., a piece of white 
ABS pipe, with plenty of airflow thhrough it, or a polished aluiminum 
enclosure with plenty of airflow?)   Simply place it under an "awning" 
laid out to insure that no sunlight impinges directly upon the sensor?   
How far fromthe inner surface of this awning would thesensor need to be, 
not to pick up erroneous readings due to radiation of heat fromthe awning?

*heh*  sometimes my mind asks too many quesitons, eh?

tom

Re: [AVR-Chat] Re: AVR weather station for newbie...

2006-01-10 by Ralph Hilton

On Tue, 10 Jan 2006 15:45:46 -0000 you wrote:

>--- In AVR-Chat@yahoogroups.com, Ralph Hilton <ralph@r...> wrote:
>>
>http://www.prllc.com/productcart/pc/viewPrd.asp?idcategory=6&idproduct=12
>> 
>> Chapter 5, Project Development
>> This chapter focuses on the orderly development of a project using
>microcontrollers.  A
>> complete wireless indoor/outdoor weather station is developed in its
>entirety to
>> illustrate the process.
>> --
>
>thanks ralph. but is that an expensive book or what? perhaps it's
>targeting people in the embedded system industry and not for hobbyists...

It seems in line with computer book costs which are generally quite high.
I got mine from Amazon.co.uk which was cheaper.
--
Ralph Hilton
http://www.ralphhilton.org
C-Meter: http://www.cmeter.org
FZAOINT http://www.fzaoint.net

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by John Samperi

At 02:25 AM 11/01/2006, you wrote:

>   So...has anyone here overclocked AVR chips?

What is the fascination with over clocking chips?
So far I run my chips at 8MHz (half the max speed )
and find myself putting a few NOPs here and there to
slow  them down. So WHY do you need to do it?


Regards

John Samperi

********************************************************
Ampertronics Pty. Ltd.
11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
Website  http://www.ampertronics.com.au
*Electronic Design * Custom Products * Contract Assembly
********************************************************

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by Micah Stevens

I looked into overclocking to facilitate a PWM scenario I needed to run. After 
calculating though, I'd need to run the chip at 80Mhz to make due, a bit 
over-spec, so I'm doing something different now. 

Just as an example,

-Micah 
Show quoted textHide quoted text
On Tuesday 10 January 2006 12:39 pm, John Samperi wrote:
>  At 02:25 AM 11/01/2006, you wrote:
>  >   So...has anyone here overclocked AVR chips?
>
>  What is the fascination with over clocking chips?
>  So far I run my chips at 8MHz (half the max speed )
>  and find myself putting a few NOPs here and there to
>  slow  them down. So WHY do you need to do it?
>
>
>  Regards
>
>  John Samperi
>
>  ********************************************************
>  Ampertronics Pty. Ltd.
>  11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
>  Tel. (02) 9674-6495       Fax (02) 9674-8745
>  Email: john@ampertronics.com.au
>  Website  http://www.ampertronics.com.au
>  *Electronic Design * Custom Products * Contract Assembly
>  ********************************************************
>
>
>
> YAHOO! GROUPS LINKS
>
>
>  Visit your group "AVR-Chat" on the web.
>  
>  To unsubscribe from this group, send an email to:
>  AVR-Chat-unsubscribe@yahoogroups.com
>  
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by Ralph Hilton

On Tue, 10 Jan 2006 13:15:54 -0800 you wrote:

>
>I looked into overclocking to facilitate a PWM scenario I needed to run. After 
>calculating though, I'd need to run the chip at 80Mhz to make due, a bit 
>over-spec, so I'm doing something different now. 

If its just the PWM clock that needs to be faster then I'd go for one of the AVR chips
with a 64MHz PWM PLL clock .

--
Ralph Hilton
http://www.ralphhilton.org
C-Meter: http://www.cmeter.org
FZAOINT http://www.fzaoint.net

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by James Hatley

Yes, good point Ralph ...

He should check out the ATtiny26, it has a really fast PWM capability.

Jim


----- Original Message ----- 
From: "Ralph Hilton" <ralph@ralphhilton.org>
To: <AVR-Chat@yahoogroups.com>
Sent: Tuesday, January 10, 2006 2:08 PM
Subject: Re: [AVR-Chat] AVR overclocking question


> On Tue, 10 Jan 2006 13:15:54 -0800 you wrote:
>
> >
> >I looked into overclocking to facilitate a PWM scenario I needed to run.
After
> >calculating though, I'd need to run the chip at 80Mhz to make due, a bit
> >over-spec, so I'm doing something different now.
>
> If its just the PWM clock that needs to be faster then I'd go for one of
the AVR chips
Show quoted textHide quoted text
> with a 64MHz PWM PLL clock .
>
> --
> Ralph Hilton
> http://www.ralphhilton.org
> C-Meter: http://www.cmeter.org
> FZAOINT http://www.fzaoint.net
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by Micah Stevens

Thanks for the tip, I'll take a look at it. I need 6 independant outputs 
though.. 

-Micah 
Show quoted textHide quoted text
On Tuesday 10 January 2006 2:25 pm, James Hatley wrote:
>  Yes, good point Ralph ...
>
>  He should check out the ATtiny26, it has a really fast PWM capability.
>
>  Jim
>
>
>  ----- Original Message -----
>  From: "Ralph Hilton" <ralph@ralphhilton.org>
>  To: <AVR-Chat@yahoogroups.com>
>  Sent: Tuesday, January 10, 2006 2:08 PM
>  Subject: Re: [AVR-Chat] AVR overclocking question
>
>  > On Tue, 10 Jan 2006 13:15:54 -0800 you wrote:
>  > >I looked into overclocking to facilitate a PWM scenario I needed to
>  > > run.
>
>  After
>
>  > >calculating though, I'd need to run the chip at 80Mhz to make due, a
>  > > bit over-spec, so I'm doing something different now.
>  >
>  > If its just the PWM clock that needs to be faster then I'd go for one of
>
>  the AVR chips
>
>  > with a 64MHz PWM PLL clock .
>  >
>  > --
>  > Ralph Hilton
>  > http://www.ralphhilton.org
>  > C-Meter: http://www.cmeter.org
>  > FZAOINT http://www.fzaoint.net
>  >
>  >
>  >
>  > Yahoo! Groups Links
>
> SPONSORED LINKS
> Atmel avr   Microcontrollers   Intel microprocessors
>   Pic microcontrollers
>
>
> YAHOO! GROUPS LINKS
>
>
>  Visit your group "AVR-Chat" on the web.
>  
>  To unsubscribe from this group, send an email to:
>  AVR-Chat-unsubscribe@yahoogroups.com
>  
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by Micah Stevens

150Khz * 8bits = 38.4 mhz.. so that would work. Which chips have the 64Mhz 
PWM? I'm not seeing it in the product overview. 

-Micah 
Show quoted textHide quoted text
On Tuesday 10 January 2006 2:08 pm, Ralph Hilton wrote:
>  On Tue, 10 Jan 2006 13:15:54 -0800 you wrote:
>  >I looked into overclocking to facilitate a PWM scenario I needed to run.
>  > After calculating though, I'd need to run the chip at 80Mhz to make due,
>  > a bit over-spec, so I'm doing something different now.
>
>  If its just the PWM clock that needs to be faster then I'd go for one of
> the AVR chips with a 64MHz PWM PLL clock .
>
>  --
>  Ralph Hilton
>  http://www.ralphhilton.org
>  C-Meter: http://www.cmeter.org
>  FZAOINT http://www.fzaoint.net
>
>
> YAHOO! GROUPS LINKS
>
>
>  Visit your group "AVR-Chat" on the web.
>  
>  To unsubscribe from this group, send an email to:
>  AVR-Chat-unsubscribe@yahoogroups.com
>  
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: [AVR-Chat] AVR overclocking question

2006-01-10 by Micah Stevens

Ahh. the Power Stage Controllers, for lighting.. interesting.. Thanks for the 
tip..

-Micah 
Show quoted textHide quoted text
On Tuesday 10 January 2006 2:45 pm, Micah Stevens wrote:
>  150Khz * 8bits = 38.4 mhz.. so that would work. Which chips have the 64Mhz
>  PWM? I'm not seeing it in the product overview.
>
>  -Micah
>
>  On Tuesday 10 January 2006 2:08 pm, Ralph Hilton wrote:
>  >  On Tue, 10 Jan 2006 13:15:54 -0800 you wrote:
>  >  >I looked into overclocking to facilitate a PWM scenario I needed to
>  > run. > After calculating though, I'd need to run the chip at 80Mhz to
>  > make due, > a bit over-spec, so I'm doing something different now.
>  >
>  >  If its just the PWM clock that needs to be faster then I'd go for one
>  > of the AVR chips with a 64MHz PWM PLL clock .
>  >
>  >  --
>  >  Ralph Hilton
>  >  http://www.ralphhilton.org
>  >  C-Meter: http://www.cmeter.org
>  >  FZAOINT http://www.fzaoint.net
>  >
>  >
>  > YAHOO! GROUPS LINKS
>  >
>  >
>  >  Visit your group "AVR-Chat" on the web.
>  >  
>  >  To unsubscribe from this group, send an email to:
>  >  AVR-Chat-unsubscribe@yahoogroups.com
>  >  
>  >  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
>
> SPONSORED LINKS
> Atmel avr   Microcontrollers   Intel microprocessors
>   Pic microcontrollers
>
>
> YAHOO! GROUPS LINKS
>
>
>  Visit your group "AVR-Chat" on the web.
>  
>  To unsubscribe from this group, send an email to:
>  AVR-Chat-unsubscribe@yahoogroups.com
>  
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: AVR overclocking question

2006-01-11 by Dave VanHorn

--- In AVR-Chat@yahoogroups.com, Micah Stevens <micah@9...> wrote:
>
> 
> I looked into overclocking to facilitate a PWM scenario I needed to 
run. After 
> calculating though, I'd need to run the chip at 80Mhz to make due, a 
bit 
> over-spec, so I'm doing something different now. 

The tiny-26 has a PLL clock that can run the I/O at 64 MHz when running 
from 8 MHz clock.  I use this to do PWM at 500kHz

Re: [AVR-Chat] AVR overclocking question

2006-01-11 by Thomas Keller

John Samperi wrote:

>At 02:25 AM 11/01/2006, you wrote:
>
>  
>
>>  So...has anyone here overclocked AVR chips?
>>    
>>
>
>What is the fascination with over clocking chips?
>So far I run my chips at 8MHz (half the max speed )
>and find myself putting a few NOPs here and there to
>slow  them down. So WHY do you need to do it?
>  
>

  Quite simple:  I have potential applicaitonsd whre a 20 Mhz processor 
simply isn't fast enough.  The obvious solution, of course,m is another 
processor family, burt I *LIKE* the architecture of the AVR and would 
prefer to utilize AVRs.  Probably ain't going ot happen, though.

 On another note, I oknow a fellow I chat with on IRC who claims to work 
at Atmel.  he asserts that Atmel will be annoucnig (most likely in march 
or April) a new family of processors tentatively dubbed "AVR32" which 
are ellegedly targetted at competing withthe ARM9 family.  Interesting, 
if true.  Per this source, some of the earlirer and smaller versionm 
will be available in SMT  packages, but most willbe BGA (not good for 
hobbyists, but then, how many hjobbyists are using ARM9 anfd higher 
processors, eh?)

tom

RE: [AVR-Chat] wireless stuff

2006-01-11 by stevech

Some other 802.15.4 vendors (ZigBee is a consortium like WiFi to define the
upper layer protocols)...

Helicomm
Crossbow
MaxStream
Dust, Inc.
Ember Networks

Home automation...
Eaton (soon)
Hawking (summer)
Show quoted textHide quoted text
-----Original Message-----
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of Thomas Keller
Sent: Tuesday, January 10, 2006 7:41 AM
To: AVR-Chat@yahoogroups.com
Subject: [AVR-Chat] wireless stuff

Kong wrote:

>there's also a wireless weather station based on pic16f873...
>http://www.circuitcellar.com/
>  
>
  Speakjing of wireless, Atmel isn't suppoting it YET, though I have 
little doubt that they will come on board eventually:


  Check out Zigbeee wireless mesh networking.   IEEE 802.15.4 standard 
for a 2.4 Ghz sprread specxtrum mesh network protocol which offers 
self-forming, self-healing network deployment, and operability withoiut 
interference inthe vicinity of other wiresless 2.4 Ghz services such as 
802.11x and Bliuetooth (no intereference ineither direction, accoirding 
to the specs)

  A quick overview:   2.4 Ghz, 250 Kbps, originally designed to support 
wireless sensor networks.  In the  base conficuration, it offers 75 
meters range, node to node.  Since the network is a mesh, so long as no 
node is any further than75 meters from any other node, the network 
maintains integrity, regardlessof overall distance from "first node" 
to:"last node."  You can alos use RF power amplifiers and hihger end 
antennae to achieve up to just shy of 1 mile of range.,

   All Zigbee capable components I have seen so far are completely 
self-contained,.  Most are embedded on a 16 or 32 bit processor, but 
have saparate ROM-based Zigbee networking stacks included, so all you do 
fromthe processor is push a few values into dsome setup registers, and 
start passing the network data.   Zigbee protocolhandlesall addressing 
issue and so on, so if a message comes acorss the network for yoiuyr 
processoir,m it gets an interrupt teling it so, with no other overhead 
inyour softeware at all.

  There are also add-on Zigbee "processors" which can be hung off the 
side of your existing uP.

    Zigbeee is very inexpensive.  One vendor will soon (1Q 06, 
allegedly) be shipping a 12.5 Mhz,m 16 bit processor with embedded 
Zigbee hardware/firmware.  Included are hardware encryption 
accelerator,m hardware based random number support,  a wide range of  
typical embedded processor peripherals, all for about US$5 qty 1.   
Believe it or not.

  There are more and more vendors jumping on the Zigbee bandwagon. My 
understanding is that Zigbee is huge in Europe (though i have no 
specific informaiton on that).

   Jennic is one vendor offering both embedded processors enabled for 
Zigbee, as well as Zigbee addons.  www.Jennic.com, IIRC.


Tom



 
Yahoo! Groups Links

Re: [AVR-Chat] AVR overclocking question

2006-01-11 by John Samperi

At 01:25 PM 11/01/2006, you wrote:
>   Quite simple:  I have potential applicaitonsd whre a 20 Mhz processor
>simply isn't fast enough.

Is it a hardware or software limitation? Can you rewrite part
(or all??) of the application in assembler perhaps? I understand
the case of a PWM scenario where you could be limited by the
PWM frequency. In other words I would NOT consider over clocking
a processor in a production unit, but that's just me, I like
things to run WELL within their specs.

Regards

John Samperi

********************************************************
Ampertronics Pty. Ltd.
11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
Website  http://www.ampertronics.com.au
*Electronic Design * Custom Products * Contract Assembly
********************************************************

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-11 by Micah Stevens

But I'll need 5-6 independant outs. The Lighting chips might do the trick, I 
need to sit down and read the datasheet, and find out how much they are, and 
if they're even available yet. 

Thanks!
-Micah 
Show quoted textHide quoted text
On Tuesday 10 January 2006 7:19 pm, Dave VanHorn wrote:
>  --- In AVR-Chat@yahoogroups.com, Micah Stevens <micah@9...> wrote:
>  > I looked into overclocking to facilitate a PWM scenario I needed to
>
>  run. After
>
>  > calculating though, I'd need to run the chip at 80Mhz to make due, a
>
>  bit
>
>  > over-spec, so I'm doing something different now.
>
>  The tiny-26 has a PLL clock that can run the I/O at 64 MHz when running
>  from 8 MHz clock.  I use this to do PWM at 500kHz
>
>
>
>
>
>
>
>
> SPONSORED LINKS
> Atmel avr   Microcontrollers   Intel microprocessors
>   Pic microcontrollers
>
>
> YAHOO! GROUPS LINKS
>
>
>  Visit your group "AVR-Chat" on the web.
>  
>  To unsubscribe from this group, send an email to:
>  AVR-Chat-unsubscribe@yahoogroups.com
>  
>  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-11 by James Hatley

I couldn't find any at90pwm at www.findchips.com yet.

How about 6 ATtiny26s one for each PWM? they are inexpensive...

Jim
Show quoted textHide quoted text
----- Original Message ----- 
From: "Micah Stevens" <micah@9250x.com>
To: <AVR-Chat@yahoogroups.com>
Sent: Wednesday, January 11, 2006 9:09 AM
Subject: Re: [AVR-Chat] Re: AVR overclocking question



But I'll need 5-6 independant outs. The Lighting chips might do the trick, I
need to sit down and read the datasheet, and find out how much they are, and
if they're even available yet.

Thanks!
-Micah

On Tuesday 10 January 2006 7:19 pm, Dave VanHorn wrote:
>  --- In AVR-Chat@yahoogroups.com, Micah Stevens <micah@9...> wrote:
>  > I looked into overclocking to facilitate a PWM scenario I needed to
>
>  run. After
>
>  > calculating though, I'd need to run the chip at 80Mhz to make due, a
>
>  bit
>
>  > over-spec, so I'm doing something different now.
>
>  The tiny-26 has a PLL clock that can run the I/O at 64 MHz when running
>  from 8 MHz clock. I use this to do PWM at 500kHz
>
>
>
>
>
>
>
>
> SPONSORED LINKS
> Atmel avr   Microcontrollers   Intel microprocessors
>   Pic microcontrollers
>
>
> YAHOO! GROUPS LINKS
>
>
> Visit your group "AVR-Chat" on the web.
>
> To unsubscribe from this group, send an email to:
> AVR-Chat-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.



Yahoo! Groups Links

Re: [AVR-Chat] AVR overclocking question

2006-01-11 by Zack Widup

On Wed, 11 Jan 2006, John Samperi wrote:

> At 01:25 PM 11/01/2006, you wrote:
> >   Quite simple:  I have potential applicaitonsd whre a 20 Mhz processor
> >simply isn't fast enough.
> 
> Is it a hardware or software limitation? Can you rewrite part
> (or all??) of the application in assembler perhaps? I understand
> the case of a PWM scenario where you could be limited by the
> PWM frequency. In other words I would NOT consider over clocking
> a processor in a production unit, but that's just me, I like
> things to run WELL within their specs.
> 
> Regards
> 
> John Samperi
> 

I have been playing around with the direct digital synthesis project on 
Jesper's AVR page:

http://www.myplace.nu/avr/minidds/index.htm

If you want an output of more than a few hundred kHz, you either need to 
overclock the AVR, use frequency multiplication, or find something faster 
(if it exists). 

Zack

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-11 by Micah

I was considering that. It's not out of the question as I could have a 
master controller feed instructions to them upon boot I think, I didn't 
look at the details of how the tiny26s get their instruction code, but I 
would bet I could feed it from a bigger micro.

-Micah


James Hatley wrote:
Show quoted textHide quoted text
> I couldn't find any at90pwm at www.findchips.com yet.
>
> How about 6 ATtiny26s one for each PWM? they are inexpensive...
>
> Jim
>
> ----- Original Message -----
> From: "Micah Stevens" <micah@9250x.com>
> To: <AVR-Chat@yahoogroups.com>
> Sent: Wednesday, January 11, 2006 9:09 AM
> Subject: Re: [AVR-Chat] Re: AVR overclocking question
>
>
>
> But I'll need 5-6 independant outs. The Lighting chips might do the 
> trick, I
> need to sit down and read the datasheet, and find out how much they 
> are, and
> if they're even available yet.
>
> Thanks!
> -Micah
>
> On Tuesday 10 January 2006 7:19 pm, Dave VanHorn wrote:
> >  --- In AVR-Chat@yahoogroups.com, Micah Stevens <micah@9...> wrote:
> >  > I looked into overclocking to facilitate a PWM scenario I needed to
> >
> >  run. After
> >
> >  > calculating though, I'd need to run the chip at 80Mhz to make due, a
> >
> >  bit
> >
> >  > over-spec, so I'm doing something different now.
> >
> >  The tiny-26 has a PLL clock that can run the I/O at 64 MHz when running
> >  from 8 MHz clock. I use this to do PWM at 500kHz
> >
> >
> >
> >
> >
> >
> >
> >
> > SPONSORED LINKS
> > Atmel avr   Microcontrollers   Intel microprocessors
> >   Pic microcontrollers
> >
> >
> > YAHOO! GROUPS LINKS
> >
> >
> > Visit your group "AVR-Chat" on the web.
> >
> > To unsubscribe from this group, send an email to:
> > AVR-Chat-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>
>
> SPONSORED LINKS
> Atmel avr 
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Re: [AVR-Chat] AVR overclocking question

2006-01-12 by Thomas Keller

John Samperi wrote:

>At 01:25 PM 11/01/2006, you wrote:
>  
>
>>  Quite simple:  I have potential applicaitonsd whre a 20 Mhz processor
>>simply isn't fast enough.
>>Is it a hardware or software limitation? Can you rewrite part
>>(or all??) of the application in assembler perhaps? I understand
>>the case of a PWM scenario where you could be limited by the
>>PWM frequency. In other words I would NOT consider over clocking
>>a processor in a production unit, but that's just me, I like
>>things to run WELL within their specs.
>>
>>    
>>
  In this case, it is a software issue.   Sinmply not enough time to 
execute all the necessarty instrucitonsd at a measly 20 Mhz.  (OK, I 
admit it, I've been spoit by 100 Mhz, 600 Mhz, 3.8 Ghz Intel Crapiums)  
But seriously, the primary project I have in mind would require at 
*LEAST* an 800 MIPs (hopefully that would mean an 800 Mhz) processor, 
which is **WAY** outside what we're ever going to see in an AVR.  An 
ARM9 ( or that new ARM processor, that will supposedly sclae to at least 
1 Ghz, and which, oddly enough, QualComm, of all companies, has 
licensed), or maybe from the new AVR32 line (to which I alluded in an 
eariler post), but not bloody likely in an 8 bit AVR, even though, aside 
from the speed issue, my app doesn't really need any more than an 8 bit 
processor. *sigh*  (a 32 bit 100 Mhz logic analyzer, in case you're 
wondering, with up to 16 Mbytes of logging capacity) [of course, doiing 
it with a 32 bit processor would considerably simnplify certain aspects 
of the design and software]

  Mostly, I was just not quite "idly" curious.


tom

Re: [AVR-Chat] AVR overclocking question

2006-01-12 by Thomas Keller

Zack Widup wrote:

>On Wed, 11 Jan 2006, John Samperi wrote:
>  
>
>>At 01:25 PM 11/01/2006, you wrote:
>>    
>>
>>>   Quite simple:  I have potential applicaitonsd whre a 20 Mhz processor
>>>simply isn't fast enough.
>>>      
>>>
>>Is it a hardware or software limitation? Can you rewrite part
>>(or all??) of the application in assembler perhaps? I understand
>>the case of a PWM scenario where you could be limited by the
>>PWM frequency. In other words I would NOT consider over clocking
>>a processor in a production unit, but that's just me, I like
>>things to run WELL within their specs.
>>I have been playing around with the direct digital synthesis project on 
>>Jesper's AVR page:
>>
>>http://www.myplace.nu/avr/minidds/index.htm
>>
>>If you want an output of more than a few hundred kHz, you either need to 
>>overclock the AVR, use frequency multiplication, or find something faster 
>>(if it exists). 
>>    
>>
  Oh, it exists.   One can easily find 25 and 40 MIPS capable 8051 
derivatives  out there, and there are literally DOZENS of smeiconductor 
makers with proprietary 8 bit (an.d.or 16 and/or 32 bit) 
Ucontrollers/uPorcessors out there.  But I am lazy and picky.  I want to 
do it on the AVR  architecture, even though, for reaosns alluded to in 
my reply to john, I know it cannot POSSIBLY be (unless I choose to 
implment an AVR clone running at many hundreds of Mhz in an FPGA (and 
don't laugh...www.opencoure.org (I think that's right) has the VHDL code 
in open source form to create a generic AVR processor in a Xilinx FPGA 
that will easily run at 50 Mhz.   Not counting the cot of the FPGA 
development system/programming hardware, it would cost about $25 or so 
to make of those.  I may actually do this someday, just for the hell of it))

tom

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Thomas Keller

Micah Stevens wrote:

>But I'll need 5-6 independant outs. The Lighting chips might do the trick, I 
>need to sit down and read the datasheet, and find out how much they are, and 
>if they're even available yet. 
>
>Thanks!
>-Micah 
>
>On Tuesday 10 January 2006 7:19 pm, Dave VanHorn wrote:
>  
>
>> --- In AVR-Chat@yahoogroups.com, Micah Stevens <micah@9...> wrote:
>> > I looked into overclocking to facilitate a PWM scenario I needed to
>>
>> run. After
>>
>> > calculating though, I'd need to run the chip at 80Mhz to make due, a
>>
>> bit
>>
>> > over-spec, so I'm doing something different now.
>>
>> The tiny-26 has a PLL clock that can run the I/O at 64 MHz when running
>> from 8 MHz clock.  I use this to do PWM at 500kHz
>>    
>>

   Or use one of the serial input PWM driver chips available form any 
number of vendors, and control it with the AVR lighting chip. *heh*

Tom

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Thomas Keller

James Hatley wrote:

>I couldn't find any at90pwm at www.findchips.com yet.
>
>How about 6 ATtiny26s one for each PWM? they are inexpensive...
>

   Interesting.  I hadn't noticed that Digikey doesn't actuyally list 
the AT90PWM chips.

   I have a couple of AT90PWM3s Atmel sampled me, so they *ARE* 
avaialble.  Might have to contact Atmel directly to find out how to buy.

Tom

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Thomas Keller

Micah wrote:

>I was considering that. It's not out of the question as I could have a 
>master controller feed instructions to them upon boot I think, I didn't 
>look at the details of how the tiny26s get their instruction code, but I 
>would bet I could feed it from a bigger micro.
>  
>
   Not a problem. You just program then with generic code which can 
request or accept control parameters via a parallel or serial input port.

tom

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Micah Stevens

On Wednesday 11 January 2006 8:27 pm, Thomas Keller wrote:
>
>     Or use one of the serial input PWM driver chips available form any
>  number of vendors, and control it with the AVR lighting chip. *heh*
>

Links? I didn't see any that fit my purpose that weren't $20 a chip.

-Micah

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Thomas Keller

Micah Stevens wrote:

>
>On Wednesday 11 January 2006 8:27 pm, Thomas Keller wrote:
>  
>
>>    Or use one of the serial input PWM driver chips available form any
>> number of vendors, and control it with the AVR lighting chip. *heh*
>>
>>    
>>
>
>Links? I didn't see any that fit my purpose that weren't $20 a chip.
>  
>
  I'll see what I can find.   $20 oisn't bad, though.  Keep in mind that 
your boards become more complex and more expensive, and your reliabilty 
goes down with every additional chip you use.  So, is $20 really allthat 
expensive?  You'd be replacing 6 8 pin DIPS with an 8 pin DIP and a 16 
(24?) pin DIP.  Much simpler to fabricate, less expensive and smaller 
PCB,. 

   Now, if this is a one-off project, many of these issues will be 
irrelevant, but if you're planning to produce these boards for sale, the 
size and cost of the PCB is going to become MUCH more relevant to you.

tom

Re: [AVR-Chat] AVR overclocking question

2006-01-12 by Richard Reeves

Zack:
> I have been playing around with the direct digital synthesis project
> on Jesper's AVR page:
> 
> http://www.myplace.nu/avr/minidds/index.htm
> 
> If you want an output of more than a few hundred kHz, you either need
> to overclock the AVR, use frequency multiplication, or find something
> faster (if it exists). 
The Analog Devices DDS range are really nice chips and some have 
internal PLLs to get the high output frequencies with a (relatively) 
low frequency master clock.  Cheap, easy to work with, and if you 
don't expect them to give decent sines beyond a fifth to a quarter of 
the MCLK, well worth using.





Richard---
"Iz dana u dan ona dolazi i odlazi u talasima"
   http://www.van-gogh.co.yu/

Re: [AVR-Chat] Re: AVR overclocking question

2006-01-12 by Micah

Thomas Keller wrote:

> Micah Stevens wrote:
>
> >
> >On Wednesday 11 January 2006 8:27 pm, Thomas Keller wrote:
> > 
> >
> >>    Or use one of the serial input PWM driver chips available form any
> >> number of vendors, and control it with the AVR lighting chip. *heh*
> >>
> >>   
> >>
> >
> >Links? I didn't see any that fit my purpose that weren't $20 a chip.
> > 
> >
>   I'll see what I can find.   $20 oisn't bad, though.  Keep in mind that
> your boards become more complex and more expensive, and your reliabilty
> goes down with every additional chip you use.  So, is $20 really allthat
> expensive?  You'd be replacing 6 8 pin DIPS with an 8 pin DIP and a 16
> (24?) pin DIP.  Much simpler to fabricate, less expensive and smaller
> PCB,.
>
>    Now, if this is a one-off project, many of these issues will be
> irrelevant, but if you're planning to produce these boards for sale, the
> size and cost of the PCB is going to become MUCH more relevant to you.
>
> tom

Agreed. I verified today the availability of production quantities of 
the AT90PWM series chips, and these seem to have sufficient resources to 
do what I need. I'm still wrapping my head around the PWM peripheral, 
but so far it looks pretty good. So, at less than $5, for these, yes, 
$20 is a lot.

-Micah

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