Would really like input/opinions on the ARM/CORTEX M3

>"linnix" <me@linnix.info-for.us> wrote in message 
>news:5825b6fb-e219-4b8d-8d3f-60a1dd5a1281@r8g2000prm.googlegroups.com...
>> Oh, I am talking about Salado, Texas

>Yes, I do mean CA and TX.  I routinely work with NY (4 hours) and
>SZ,CN (12 hours).

>I will do a pcb prototype soon, probably with tqfp48 (STM32F103C8T6)
>and micro USB.

>Look like the board has 8MHz crystal.  Wonder why they didn't use
>25MHz.

The STM32Fs have an on chip 8MHz RC oscillator and a PLL to get to 72MHz 
(for the 'performance' parts).

Using an 8MHz crystal means that the power in the oscillator is reasonable 
and that you can switch between internal and external clocks without 
changing anything else.

This can burn you if you have code that defaults to the local oscillator 
because everything looks great but the clock is not as accurate as you 
expected. (I once spent some time debugging a system which did this - bad 
connection between external clock and processor so the clock on the board 
looked good but the UART ran at not quite the right speed.)

Michael Kellett

In article <5825b6fb-e219-4b8d-8d3f-60a1dd5a1281
@r8g2000prm.googlegroups.com>, me@linnix.info-for.us says...
> 
> On Dec 30, 8:40&#4294967295;pm, justme <jble...@gmail.com> wrote:
> > Oh, I am talking about Salado, Texas
> 
> Yes, I do mean CA and TX.  I routinely work with NY (4 hours) and
> SZ,CN (12 hours).

Currently in UK working with people in Europe and Texas and Florida.


-- 
Paul Carpenter          | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/>    PC Services
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<http://www.gnuh8.org.uk/>  GNU H8 - compiler & Renesas H8/H8S/H8 Tiny
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On Dec 31, 12:25=A0am, "Michael Kellett" <nos...@nospam.com> wrote:
> >"linnix" <m...@linnix.info-for.us> wrote in message
> >news:5825b6fb-e219-4b8d-8d3f-60a1dd5a1281@r8g2000prm.googlegroups.com...
> >> Oh, I am talking about Salado, Texas
> >Yes, I do mean CA and TX. =A0I routinely work with NY (4 hours) and
> >SZ,CN (12 hours).
> >I will do a pcb prototype soon, probably with tqfp48 (STM32F103C8T6)
> >and micro USB.
> >Look like the board has 8MHz crystal. =A0Wonder why they didn't use
> >25MHz.
>
> The STM32Fs have an on chip 8MHz RC oscillator and a PLL to get to 72MHz
> (for the 'performance' parts).
>
> Using an 8MHz crystal means that the power in the oscillator is reasonabl=
e
> and that you can switch between internal and external clocks without
> changing anything else.
>
> This can burn you if you have code that defaults to the local oscillator
> because everything looks great but the clock is not as accurate as you
> expected. (I once spent some time debugging a system which did this - bad
> connection between external clock and processor so the clock on the board
> looked good but the UART ran at not quite the right speed.)

Yes, USB PLL needs 48MHz and CPU PLL needs 72MHz.  I would probably
pick 24MHz crystal.  You need code to switch between RC and XTAL
anyway.

On Thu, 30 Dec 2010 12:25:04 -0800, Mark Borgerson wrote:
<snip>

>> >
>> OTOH, there are horror stories as well.  Needed to other some parts.
>> Digikey and Mouser don't stock them, and need to buy 1000 and wait
>> several weeks. Canadian F* got them, and better prices in small qty.
>> Got in the web.  Entered the order.  Punched in credit card number.
>> Submitted...  Nothing happen.  Got back to the main screen.  Reg. with
>> new account.  Login with new account.  Wrong Password!!!  Click on
>> forgot password link.  Check my email.  Nothing there.  Tried "forgot
>> password" again.  Still Nothing.  Call them.  The one lady handling all
>> internet sale was out to lunch.  Tried again the next day.  She needed
>> to email me the account form.  Next day, still nothing in email.
>> 
>> Forget it, I'll buy 1000 from Digikey.  If I have so much trouble
>> before paying, what would happen after paying F*.
> 
> I must admit I've made design decisions based on what's available at
> DigiKey only to get bitten on the butt two years later when the parts
> were out of stock with 12-week lead times.  In general, when they're out
> of stock at DigiKey, they're also hard to find from other sources.  
> Alas, that has happened when a customer placed an order that doubled the
> annual volume for a particular board. They hate it when you say you can
> deliver 10 this week, but the next 30 may be 12 weeks out.   Of course,
> those orders always come in just before vacations or holidays!  ;-(
> 
> 
> Alas, for companies with small volumes in niche markets, inventory
> control can be more magic than management.    I don't want to retire in
> a few years with two years worth of parts unused on the shelf.
> 
> 
> Mark Borgerson

My ritual is to have browser tabs open to Mouser, DigiKey, AvnetExpress
and Arrow.  I find that for many parts Avnet has a better price even
in the <100 piece count. I needed a couple hundred ULN2803 a while back
and Mouser/Digikey did not have enough.  I was able to buy a 1000 pack
from Avnet for only a few dollars more than the price I was going to pay
Mouser and DigiKey for a few hundred.  I'm set on 2803's for while :)
Avnet has standard fedex ground shipping for $8 I think it is.  I usually
get the parts in 2 days from Tempe, AZ.

I have found that for some parts Jameco can have good prices and stock
on hand.  Jameco had some Omron relays I needed when everyone else was
short on stock.

OnSemi, MicroChip, Fairchild, Kingbright and some others that I cannot
think of off the top of my head, have online ordering.  I can usually
get parts directly from MicroChip in 2 or 3 days with their standard
fedex shipping.  They must fill that big blue jet from Thailand each
night.

The good news is the days of having to deal with some rep that does
not want to return your call because you dont need 10K pieces are
gone.  


-- 
Joe Chisolm
Marble Falls, Tx.

In article <v-OdnZ4_3vmH2IPQnZ2dnUVZ_qidnZ2d@earthlink.com>, jchisolm6
@earthlink.net says...
> 
> On Thu, 30 Dec 2010 12:25:04 -0800, Mark Borgerson wrote:
> <snip>
> 
> >> >
> >> OTOH, there are horror stories as well.  Needed to other some parts.
> >> Digikey and Mouser don't stock them, and need to buy 1000 and wait
> >> several weeks. Canadian F* got them, and better prices in small qty.
> >> Got in the web.  Entered the order.  Punched in credit card number.
> >> Submitted...  Nothing happen.  Got back to the main screen.  Reg. with
> >> new account.  Login with new account.  Wrong Password!!!  Click on
> >> forgot password link.  Check my email.  Nothing there.  Tried "forgot
> >> password" again.  Still Nothing.  Call them.  The one lady handling all
> >> internet sale was out to lunch.  Tried again the next day.  She needed
> >> to email me the account form.  Next day, still nothing in email.
> >> 
> >> Forget it, I'll buy 1000 from Digikey.  If I have so much trouble
> >> before paying, what would happen after paying F*.
> > 
> > I must admit I've made design decisions based on what's available at
> > DigiKey only to get bitten on the butt two years later when the parts
> > were out of stock with 12-week lead times.  In general, when they're out
> > of stock at DigiKey, they're also hard to find from other sources.  
> > Alas, that has happened when a customer placed an order that doubled the
> > annual volume for a particular board. They hate it when you say you can
> > deliver 10 this week, but the next 30 may be 12 weeks out.   Of course,
> > those orders always come in just before vacations or holidays!  ;-(
> > 
> > 
> > Alas, for companies with small volumes in niche markets, inventory
> > control can be more magic than management.    I don't want to retire in
> > a few years with two years worth of parts unused on the shelf.
> > 
> > 
> > Mark Borgerson
> 
> My ritual is to have browser tabs open to Mouser, DigiKey, AvnetExpress
> and Arrow.  I find that for many parts Avnet has a better price even
> in the <100 piece count. I needed a couple hundred ULN2803 a while back
> and Mouser/Digikey did not have enough.  I was able to buy a 1000 pack
> from Avnet for only a few dollars more than the price I was going to pay
> Mouser and DigiKey for a few hundred.  I'm set on 2803's for while :)
> Avnet has standard fedex ground shipping for $8 I think it is.  I usually
> get the parts in 2 days from Tempe, AZ.
> 
> I have found that for some parts Jameco can have good prices and stock
> on hand.  Jameco had some Omron relays I needed when everyone else was
> short on stock.

I like Jameco for connectors and headers.  Their prices are often a 
fraction of the Newark and DigiKey prices.  I also like to sample the
robotics stuff---but I too often end up with toys that go unused.  ;-(

If I ever retire, I've got at least two years worth of robotic
hardware and Cortex dev kits to keep me busy.  

> 
> OnSemi, MicroChip, Fairchild, Kingbright and some others that I cannot
> think of off the top of my head, have online ordering.  I can usually
> get parts directly from MicroChip in 2 or 3 days with their standard
> fedex shipping.  They must fill that big blue jet from Thailand each
> night.
> 
I quite often go to the TI,  Analog Devices, and Maxim Direct sites for 
parts that aren't available other places.

> The good news is the days of having to deal with some rep that does
> not want to return your call because you dont need 10K pieces are
> gone.  
That's true.  I worked through a rep for about 6 years with SAMTEC
connectors before they got their own direct-purchase web site
up and running.



Mark Borgerson

Well, Rick, I was just hoping to find someone that woudn't mind
answering some questions in the begging of my implementing the Cortex
M3.  In tha past, I have found that this can give one an exponential
jump in coming up to speed.  There is a tremendous waste of time in
trying to 'get there' by searching and reading stuff that is really
not needed to what one is actually looking for.  Kind of a 'pay it
forward' type of thing rather than mooching on other's good graces.

Naturally, if the receptor is greedy, he can run the donor crazy.
That is not me.



Joe



On Thu, 30 Dec 2010 18:40:08 -0800 (PST), rickman <gnuarm@gmail.com>
wrote:

>On Dec 30, 8:29&#4294967295;pm, justme <jble...@gmail.com> wrote:
>> I really admire those companies that understand that expedience builds
>> loyalty.
>>
>> I do not see how that STM can sell this eval. board for this price
>> except that it is, for them, a loss leader that will pay off hugely
>> when designs reach fruition.
>>
>> I wish that there was someone around here, near
>> Salado, that could collaborate on the Cortex M3.
>>
>> Yes, the agility of a small company can reap huge rewards.
>>
>> Joe
>
>What sort of collaboration are you thinking of?  I have never found
>distance to be much of an issue in regards to collaboration.  Time and
>motivation are usually much bigger factors whether a business project
>or a hobby project.
>
>Rick

I understand, but that really isn't collaboration.  You are asking for
a mentor.

Rick


On Jan 1, 8:34=A0pm, justme <jble...@gmail.com> wrote:
> Well, Rick, I was just hoping to find someone that woudn't mind
> answering some questions in the begging of my implementing the Cortex
> M3. =A0In tha past, I have found that this can give one an exponential
> jump in coming up to speed. =A0There is a tremendous waste of time in
> trying to 'get there' by searching and reading stuff that is really
> not needed to what one is actually looking for. =A0Kind of a 'pay it
> forward' type of thing rather than mooching on other's good graces.
>
> Naturally, if the receptor is greedy, he can run the donor crazy.
> That is not me.
>
> Joe
>
> On Thu, 30 Dec 2010 18:40:08 -0800 (PST), rickman <gnu...@gmail.com>
> wrote:
>
> >On Dec 30, 8:29 pm, justme <jble...@gmail.com> wrote:
> >> I really admire those companies that understand that expedience builds
> >> loyalty.
>
> >> I do not see how that STM can sell this eval. board for this price
> >> except that it is, for them, a loss leader that will pay off hugely
> >> when designs reach fruition.
>
> >> I wish that there was someone around here, near
> >> Salado, that could collaborate on the Cortex M3.
>
> >> Yes, the agility of a small company can reap huge rewards.
>
> >> Joe
>
> >What sort of collaboration are you thinking of? =A0I have never found
> >distance to be much of an issue in regards to collaboration. =A0Time and
> >motivation are usually much bigger factors whether a business project
> >or a hobby project.
>
> >Rick
>
>

Rick,

What is your goal in dissecting this request of mine?  Are you hung up
on the taxonomy of the request.  I really don't want someone to hold
my hand in my endeavor rather, someone who wouldn't mind answering a
few questions about resources that would answer all of my questions.

Thank you for your concern.

Joe




On Sat, 1 Jan 2011 21:29:05 -0800 (PST), rickman <gnuarm@gmail.com>
wrote:

>mentor

On Jan 2, 10:57=A0pm, justme <jble...@gmail.com> wrote:
> Rick,
>
> What is your goal in dissecting this request of mine? =A0Are you hung up
> on the taxonomy of the request. =A0I really don't want someone to hold
> my hand in my endeavor rather, someone who wouldn't mind answering a
> few questions about resources that would answer all of my questions.
>
> Thank you for your concern.
>
> Joe

My goal was to figure out if you were someone I would be interested in
collaborating with.

I won't mind helping you if you are interested in email help.
Arranging time for phone conversations is a bit harder.

Rick

On Jan 2, 8:26=A0pm, rickman <gnu...@gmail.com> wrote:
> On Jan 2, 10:57=A0pm, justme <jble...@gmail.com> wrote:
>
> > Rick,
>
> > What is your goal in dissecting this request of mine? =A0Are you hung u=
p
> > on the taxonomy of the request. =A0I really don't want someone to hold
> > my hand in my endeavor rather, someone who wouldn't mind answering a
> > few questions about resources that would answer all of my questions.
>
> > Thank you for your concern.
>
> > Joe
>
> My goal was to figure out if you were someone I would be interested in
> collaborating with.

Me too.  I would like to collaborating with people working on LPC1343/
STM103 prototypes.  I can draft the PCB layout, using: USB micro B,
TQFP48 and one or more high density FPC connectors.  I can order a
batch of FPC connecting cables one time, for connecting boards.  Sizes
and shapes are open for suggestions.

>
> I won't mind helping you if you are interested in email help.
> Arranging time for phone conversations is a bit harder.

Me three.  And I am always here in C.A.E.