I'm new to microcontrollers world.

I have only a little experience with Z80 based systems.

I saw some Atmel AVR's sources and I loved it: very clear.

Someone suggest me to start with PIC, someone else with AVR.

The net is full of doc/projects about PIC and give me a bit of
confusione; AVR much less...instead.

What do you think about? What's the best approach for a beginner?

Thanks in advance

[Frank] wrote:

If you are on a path to doing very large projects you want to use the
AVR -- it has more of a 'big processor' feel to it, it works better with
C than a PIC, and there are free C compilers available.

If all you ever need is an itty bitty sequencer, then there's no
technical reason to choose an AVR over a PIC.

Generally I choose microprocessors based on the following:

* Do they have the peripherals I need? Often the features that
drive my decision is whether I can do what I want with the
peripheral set; the core is just what happens to be attached
to the peripherals.

* Do the pins have enough oomph to do what I want? A circuit with
a processor and a bunch of drivers is much larger than a circuit
with just a processor. IIRC the PIC and the TI MPS430 excel at
this.

* Will it be fast enough, and big enough? You have to be careful
here -- you're not just looking for raw speed and storage, but
speed and storage as you're going to use them. Both the MPS430
and the AVR fit C better than the PIC does, which means that
they get more out of the underlying resources than the PIC if
you're using the language. If all you're going to use is
assembly, then it's not so big a deal.

* For small projects I look at how familiar I am with the chip,
because it takes time to spin up on a new architecture. For
large projects I figure that the time to learn the new
architecture and the expense of new tools will be paid back
in efficiency as time goes on -- this is obviously a judgment
call, and one that should be made carefully.

--

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

If it's my choice, I pick the micro and ask for additional money for
different micro. For example:

1. Arm (cost)
2. Avr (cost + 100)
3. Freescale (cost + 300)
4. MSP (cost + 500)
5. PIC (cost + 1000)

I will do any micro with the right price. Otherwise, I prefer ARM M3
Cortex nowaday, except for very low power and code density with AVR.
ARM M3 is around 30% higher in power and 40% higher in code space than
AVR, but a non-issue most of the time.

The LMI chips meet most of what I need, except for the relatively new
company. TI and ST are coming on-line with M3 soon. Hopefully, they
will have parts close enough to LMI.

On Feb 19, 1:54 pm, "[Frank]" <____n...@email.it> wrote:

You will see violently different opinions on this.

Many people learned their first micro projects on the PIC. Many
learned their first projects on the AVR.

If you have experience with Z80 code, you will not have terrible
difficulty picking up either architecture, but the AVR will be more
familiar to you (not that it's particularly Z80-like, but it's simply
less weird than PIC).

Having used both architectures, my preference is strongly for AVR.

[Frank] wrote:
Download the tool sets and try them. Find one you like.

Or choose an application, and work backwards from there.

I suggest you also look at
SiLabs C8051F family, and their ToolSticks
TI MSP 430 family, Similar toolsticks, but no 5V parts
Zilog's devices, since you already have some background there
eZ80, Z8F, ZENO etc
Freescale, who are having a push on their smaller parts.

-jg

[Frank] wrote:

This will give you some info to get started Frank:
http://www.dontronics-shop.com/pages.php?pageid=23

Don...


--
Don McKenzie
E-Mail Contact Page: http://www.dontronics.com/e-mail.html

Crystal clear, super bright OLED LCD (128x128) for your microcontroller.
Simple serial RX/TX interface. Many memory sizes.
http://www.dontronics-shop.com/produ...roductid=16460

No More Damn Spam: http://www.wizard-of-oz.com

[Frank] wrote:


It does not really matter which micro to start with. Whatever you do,
you will screw up for many times. However:

1. Beware: PIC is addictive and brain damaging, especially for the
beginners.

2. All of the hardware that you need to start working the AVR is 5 wires
connected to the PC LPT port.

3. AVR is much better for C/C++ programming.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

On 2007-02-19, Tim Wescott <tim@seemywebsite.com> wrote:
AVRs certainly do not, anyway. In fact, Atmel is taking the AVRs in the
opposite direction, and has halved the specified source and sink current
recently in some newer parts (e.g. TinyX61). Very disappointing for us!
I hope they reconsider.

[Frank] wrote:
As most people tend to suggest AVR,
(I've chozen PIC, and I'm very happy with them ;-)
a few pros for PIC:
- the availability of PICs is much better ("Microchip cares about small customers")
- there are number of good C-like, Basic-like, Pascal-like, Python-like freeware compilers
(e.g. JAL v2: (including a complete IDE), see
http://www.wattystuff.net/tiki/tiki-...page=PIC+Micro
- the number of peripherals per pin is very high on PICs
- the JAL community is very helpful in solving problems (don't know the status of AVR groups)

Maybe the most important factor, determining your choice: "what's your neighbor using ?",
so you can get help with those small but nasty startup problems.

cheers,
Stef Mientki

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1171910012.299179.171790@m58g2000cwm.googlegr oups.com...
<SNIP>
Now that bit definitely is true. The PIC achitecture sure is weird. But
I've been coding PICs in assembler for what must be about 2-years now so am
almost used to it.

The PIC makes you think, ALOT. But I find there are things you can do with
them that are just mind boggling amazing. Being able to multiply and divide
a 24-bit number in 4 clock cycles on a 40 MIPS dsPIC makes you wonder where
you'd been all your life. That's like 100nanoseconds!!

But PICs sure are weird. As I have become programming them.

Also, each PIC release architecture is almost drastically different from the
next, ie. 12F, 16F, 18F, 30F. Things like getting used to having the target
register on the left, is now on the right. Perculiar stuff like that.

The PICs though I find a joy to program.

On Feb 19, 12:54 pm, "[Frank]" <____n...@email.it> wrote:
AVR butterfly + free C gcc complier is $20 , a nice cheap startup kit,
you can mix C and assembler very easily with the AVR.

On Feb 19, 2:30 pm, "Aly" <,shfskf...@sliuflky4iuhdf.erl> wrote:
Not bad for 10M 24 bits.

I haven't check it yet, so not sure about /.
Arm M3 core claims to have single cycle 32 bits at 50 MHz.
20 nanoseconds 32 bits multipler for $3 is simply amazing.

On Feb 19, 5:30 pm, "Aly" <,shfskf...@sliuflky4iuhdf.erl> wrote:
24 bit? divide alone is 18 cycles on a dsPIC.

Aly wrote:
From what I've read of the specs, the dsPIC is a whole new beast, very
different from its little PIC siblings. I also remember reading something
about an engineer at Microchip saying that basically the dsPIC was a new
core with just a bit of PIC likeliness bolted on.

YMMV as usual, but while I tend to seriously dislike the PICs, I'm quite
neutral regarding the dsPIC. It seems to be a clean and nice design; I'll
wait until I'll actually work with it to make up my mind.

Regards,
D.

Terran Melconian wrote:
Very unlikely.
There is a general trend downwards in drive ability in uC, as they push
the die sizes down. 8-10mA is now a common spec point, with PIN maxs
in the region of 25mA, and package Max's 100-200mA.

If you want more on one pin, add a transistor.

If you want to push many-pin drive, you are better with CPLDs, where the
package limits are 500mA @ 44pin or 1000mA @ 100pin

-jg

Jim Granville wrote:
I second JG on his Zilog mention. They have a few different families, and
quite a lot of different parts in the Z8 Encore! (XP or not) one.

The main Z8 Encore! advantages I see are:
- very low cost dev kits, including USB probes
- free development environment: asm, unlimited C compiler, debugger, ...
- good documentation
- not a choice of peripherals as wide as Microchip's, but good ones (one of
Zilog's historical strengths)
- low cost chips, and they're available in DIP packages! (Someone with more
experience and buying budget might give you a more accurate picture when it
comes to large-quantity prices.)

I must say I'm biased, as for some reason I'm very much at home with the
Zilog chips, much more than with other architectures. I like their assembly,
the way they're set up and so on, but of course you would have to check for
yourself, Z80 background or not.

The ZNEOs, the new 16-bitters in the family, seem to be very very nice
chips. Well I say 16-bitters, but actually they're 32-bit chips with a
24-bit address space and a 16-bit bus width... Their design is clean, and
although I have not yet taken the time to do a proper systematic analysis,
they seem to be close to a Z80000 running in Z8000 mode (ie with the 24 bits
address space, just like the Z8001). That would make them very much like the
Motorola 68000, with the possibility of evolution to a full 32-bit chip.
They're fairly orthogonal, and with 16 general-purpose registers they're
much more modern designs than the Z80/eZ80.

As with the Z8s, some low-cost dev kits are available, with free tools. Not
many parts yet though, basically variants of the same one with different
Flash and RAM sizes and with/without the external bus. This core's first
silicon errata also shows an annoying bug in the stack frame handling, so
you might want to wait for a new revision to bypass this issue.


OK, enough of the shameless plug. Zilog, you owe me on this one.

If you're planning on learning and experimenting with those chips, low-cost
kits and tools and DIP packages are pretty useful. But if you want to do
this for a living, at any rate follow all advice given to you by the wise
people of this NG: play with the tools, design you application and go
backwards from there. Best way to get the right part for the job.

Regards,
D.

"[Frank]" wrote:
I suppose this wasn't an assembly source. If you choose the
AVR, you better forget the ATMEL assembler and write your
own. I can tolerate crippled hardware (you have to make
compromises if you want small and cheap chips) but there
is no reason to use a confusing assembly syntax. Here a
example of a simple program, once written with the Atmel
assembler and once written with a clean syntax for the
AVR:

ftp://137.193.64.130/pub/assembler/uhr_e.pdf

"steve" <bungalow_steve@yahoo.com> wrote in message
news:1171926117.400805.3150@q2g2000cwa.googlegroup s.com...
You don't use the implemented MUL and DIV style instructions. You develop
your own through bit manipulation and shifting. ;-)

"Herbert Kleebauer" <klee@unibwm.de> skrev i meddelandet
news:45DAB907.78C5998F@unibwm.de...
Or use the Free IAR Assembler
--
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB

Herbert Kleebauer ha scritto:

Anyway seems Atmel AVR assembler v2 will be better.