Rabbit 3400 CPU module

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Do you know if it is possible in Rabbit 3400 CPU module to access all its
serial com ports simultaneously?
Does its C development environment support multiple threads?



Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Yes, providing there's not too much data moving around.  Stick to low
baud rates or fewer com ports running simultaneously because the Rabbit
doesn't include much in the way of FIFOs on the UARTs.

Quoted text here. Click to load it

Dynamic C has cooperative multitasking features built in which work fine
for many people.  If you're looking for POSIX threads you're out of luck.

Kelly

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Thank you for your reply.

Does Dynamic C has a simulator so that I can try writing code for Rabbit
3400 before I purchase the board? (Does Dynamic C avalible for free trial
download?)
Does the Rabbit 3400 CPU module is the only one with analog input?



Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Not that I know of - you might drop an email to the sales folks at
Rabbit and find out for sure.

Quoted text here. Click to load it

Not that I know of.

Quoted text here. Click to load it

Yes.

There is a second C compiler for the Rabbit chip from Softools.  It's
widely considered to generate faster/smaller code than Dynamic C and
also supports ANSI C, separate compilation of files, and the other
things one generally expects of a contemporary software IDE.  There's
even a free trial version.  http://www.softools.com /

Kelly

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

You may wish to look at http://www.rabbitethernetize.com , where you will
find a very good deal for a development system, complete with Dynamic C,
and a free copy of the new book on embedded design with the Rabbit 3000,
for a total of US$99.00

Bill

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Great deal - I always like buying dev kits when the company loses money
on the sale!

Kelly

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

I wonder why they aren't providing the 3700 rather than the 3720 in a
development kit.  Usually, the dev kits include the option with the
most RAM, in my experience.

Jon

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

Oh, and Kelly... they sell the 3720 at $55 in singles.  Why would you
imagine they are losing money?

Jon

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Software, cables, wall wart(s), and the book.  The best part of the deal
is that I'll now have an up-to-date copy of Dynamic C.  (Whoohoo - new
bugs to discover and work around!)

The most egregious dev kit I ever bought was from Zilog - 3 wall warts,
a 5-port 10/100 hub, at least two Cat-5 cables, and the usual RS-232
cables.  I've received a ton of use from the various pack-ins although I
can't I played with their board for more than a few hours.

Kelly

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

The dev kit includes the wall wart, the Dynamic C compiler, a
development board into which to plug the RCM3720 card, a wall chart of
info on the CPU...

I believe the module price is just that -- the price for the bare module.

Bill

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

Yes, that was my understanding.  I also note that the $99 price
appears to be gone.  But my logic for asking the question follows this
line of reasoning:

(1)  Products, including development kits, sell in qty-1 pricing with
a factor of about 4X the actual BOM costs.

(2)  If the 3720 is selling (not on special, but normally) in qty-1
for $55, I tend to imagine that the cost to put it into the shipping
box is in the $14 range.  Certainly, no more than $20.

(3)  I wasn't able to find the prototyping board separately, but lets
grant it the same cost -- somewhere from $14 to $20.

(4)  The software's manufacturing cost is nil.  There may be some
supposed lost opportunity in including it, but it's not a hard cost
item.  Further, if a developer decides to use this system in a
product, then the profits will arrive from the sales of the modules
when more than a few of them are involved (which, I'm sure, is Rabbit
Semi's hope -- no one likes the idea of having to support lots and
lots of one-off customers.)  Let's call the CD cost as $2.

(5)  The AC adapter is close to nil.  Being very gracious, call it $4.

(6)  The serial cable is also close to nil.  Neck and neck with the AC
adapter.  Frankly, I'd be surprised if it is over $2 to Rabbit.  But
let's call it $4, being the gracious folks we are.

Total?  $20*2+4*2+2 = $50 cost.  Even if I am off by a factor of two
on all these (and I'm sure I'm not that far off) then we aren't
talking about losing money.

The short of this is that I don't believe they lose money every time
they sell the kit, even at $99.  Of course, I completely understand
their desire for $199 -- as that is about 5X what I believe is their
actual cost and that is about what one tends to price at, ignoring
knowing more about the business (which I cannot pretend to know.)  And
I am willing to accept that $99 is probably good pricing worth serious
consideration, if you need their development kit and their software,
too.

By the way, I didn't notice the chart being mentioned (though I can
now see something that looks like a fold-over in the zoomed up picture
of the kit) and I haven't talked about the reference book they are
tossing in or other printed docs.  I'm sure these account for a few
dollars, as well.  But nothing to cause this to become a loss.

I remain unconvinced that they are losing money selling these at $99.
But I do suspect it is a nice deal for those needing exactly these
features and intending to buy, anyway.

Jon

Re: Rabbit 3400 CPU module
On Thu, 14 Jul 2005 21:08:56 GMT, Jonathan Kirwan

Quoted text here. Click to load it

Whoops!  I was looking NOT at the promotion page.  My bad.

Jon

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

As may be, and Kelly's assumption of a loss was likely erroneous. But so
what? Why would we wish anyone to sustain a loss?

Quoted text here. Click to load it

More relevant is that their development bundles normally list for
anywhere from $130 on up, with the lowest being for older Rabbit 2000
products. The product at the URL I specified has a normal list of $199,
which appears to be consistent with their other pricing. It has been
offered on that URL at $99, for some time now, and more recently, they
have offered the book as a free bonus.

Quoted text here. Click to load it

I sincerely hope they do not lose money. I'm happy to get a good deal,
but if the vendor bleeds for my benefit, it is not, in the long run,
likely to benefit me -- I need a supplier whose long-term health is not
uncertain.

Quoted text here. Click to load it

It is indeed a nice deal, and if it makes some modest profit for them,
so much the better. I'm a great fan of profitability, for developers,
suppliers, and others. ;)

Bill

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

And there, we can agree.  I just didn't see why anyone should imagine
they were cutting their nose off on this one.  Some manufacturers
really do, you know, lose money with the idea of making something very
nice and cheap enough so that an engineer might just buy it or get it
'on spec.'  Like an impulse item, really -- speculating that it might
be useful in the not-too-distant future.  This is how I picked up a
system for the Mot. '908's, for example -- it was exactly free.  No
question here that Motorola lost money.  And the world is confusing
enough that it is helpful to avoid going around adding to it by
conflating the cases where some manufacturers really DO lose money
with those cases where they don't.

Jon

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

Oh, absolutely! If not for profit, why are we doing all this work? ;)

I'm in favor of low-margin introductory items, but as I said before, I
want the vendor to remain healthy, else why bother to learn to use his
stuff?

Bill

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

Hmm?  I do it because I love it.  I'd do it if I weren't paid for it,
though probably less of it.

Quoted text here. Click to load it

What can I say?  I want more choices than less -- at least, that is,
if they are offering something I may need in my short lifetime,
anyway.  But I want them getting rich off of my customers, not off of
me!

More to the point, I suppose, is this:  They are the ones who have the
greater benefit if I help sell their product by designing it into a
product.  Since they reap the upside of their business, I think it is
more their capital that should be risked in the first place.  And
less, mine.  (If they want to cut me into a percentage of their
profits, I'll take up more risk.)  Or, in other words, I understand
why companies do give away excellent development tools at zero or very
reduced cost.  It can make good business sense.

But focusing back on why I said anything at all, I just prefer not to
conflate what *is* clearly a real loss-leader with what isn't.

Jon

Re: Rabbit 3400 CPU module
Quoted text here. Click to load it

The way I look at it, I paid them $99 for a compiler upgrade and couple
of software modules.  They are shipping me some additional hardware that
I don't care much about.

I don't worry too much about the why's of product pricing anymore.  The
marketeers and business wonks are supposed to be professionals.  If they
underprice their product and go out of business, it'll just make them
smarter the next time around.  Trust Darwin.

Kelly

Re: Rabbit 3400 CPU module

Quoted text here. Click to load it

There is that!  ;)

Jon

Site Timeline