Driver to drive?

[john jardine]

"Pete" <pete4242@hotmail.com> wrote in message
news:b8c37e79.0410061056.5f5202e2@posting.google.com...

I am completely newbie to microcontrollers, and that's probably why I
don't understand when Microchip's documentation for their sample
application TB055 says "C1 and C2 values selected according to crystal
load capacitance". The sample is at
http://ww1.microchip.com/downloads/en/AppNotes/91055C.pdf and the
picture is right at the beginning of the sample.

I have 20MHz PIC16C745, should I still use 6 MHz chrystal? What should
be C1 and C2 values? Or/and, how do I calculate the values of C1 and
C2?

Thanks!

Microchip PIC Data sheets have been written by lunatics.
22pF seems to work well for most* crystals used with a PIC.
Use whatever crystal you have to hand. The PIC will happily run from DC
through 20MHz.
nb: The lower frequency PICs seem surprisingly easy to overclock. For
development purposes, I've run 4MHz units quite happily at 25MHz.
regards
john

* Tiny 32,768Hz watch crystals need maybe 150kohm of external series
resistance adding or they wont work.

 

[SioL]

"john jardine" <john@jjdesigns.fsnet.co.uk> wrote in message
news:ck1rar$70e$1@news6.svr.pol.co.uk...

nb: The lower frequency PICs seem surprisingly easy to overclock. For
development purposes, I've run 4MHz units quite happily at 25MHz.
regards
john

How about AVR?

SioL

 

[Nicholas O. Lindan]

"sarah" <sarahshen2003@yahoo.ca> wrote

I run protel dxp compile PCB project and got the warning: off-grid
netlist label ... I am wondering what does it mean and how to solve
it.

Try dumping an ASCII netlist and looking at the info for the offending
component.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

 

[john jardine]

"John Todd" <tser827@yahoo.com> wrote in message
news:Xns9579465772802tser827yahoocom@129.250.170.84...

John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote in news:qGZ
$nVMQpXYBFwrm@jmwa.demon.co.uk:

I read in sci.electronics.design that Rich Grise <null@example.net
wrote (in <rKa8d.4134$eq1.3864@trnddc08&gt about 'Is this antenna
article serious?', on Mon, 4 Oct 2004:


I thought you meant that there was a specific reference to a Bussard
ramjet.


For a really great story concerning a Bussard engine,
read Poul Anderson's "Tau Zero"!

I lost my copy of it maybe 30 years ago but somewhat annoyingly I've been
stuck with an oft remembered but very hazy memory of a described spaceship
data encoding system that compressed vast amounts of data into maybe just 6
transmitted digits. The decoding and unzipping back on earth apparently
took phenomenal time and computer power.
Any idea if this the same book?.
I'd love to reread and actually *understand* what Poul was on about .
regards
jhon

 

[Rich Grise]

On Wednesday 06 October 2004 01:33 pm, Spehro Pefhany did deign to grace us
with the following:

On Wed, 06 Oct 2004 19:32:28 GMT, the renowned Rich Grise
null@example.net> wrote:

And good cross-language puns are rare.

The problem is that few can understand them, good or not.

Q: How many eggs do you need to make an omlette?
A: One is an oef.

Danny Kaye used to tell the story of the three little French

kittens, Un, Deux, and Trois. Well, one day, the three little
French kittens, Un, Deux, and Trois, were playing in the park
[he drags this part out, in a caricature French accent] The ice
on the pond was very thin. [he says, "veauhgry ssin. Not ssick,
ssin."] The little kitten,s playing on the thin ice, the thin
ice breaks, Crash!
Un, Deux, Trois, quatre, cinq.

[ducking, running]

 

[Boki]

Thank your for information, I have a problem about Bluetooth Sound device
here,

===================================================================
A. Bluetooth earphone occupy bandwidth when everytime it
connected(handshake) to PC HOST
B. Bluetooth earphone occupy bandwidth only receiving data(music).
===Which one is correct?=================================================

If (A) is correct, what a limited ...

Does it possible Bluetooth 2.0 to apply more bandwidth?


Best regards,
Boki.


"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com>
???????:41646688.EAFB1AE9@hotmail.com...

boki wrote:

Dear All,
I try to use many Bluetooth devices at the same time for my
PC/NB, when enable them individually, they will work good(The only no
good is sound quality of Bluetooth earphone). If I enable them all,
the mice move speed will drop down(like a mice taking stone) until I
stop another Bluetooth device, then the mice work normally.

The Bluetooth bandwidth is limited?

Yes, Bluetooth devices 'share' the bandwidth, so the more that are in use
in a given location, the less bandwidth each one has. It's only 732 ?
kbits/sec max available anyway, so I'm sure we'll hear plenty more about
problems with Bluetooth devices as they become more widely used.


Graham

 

[john jardine]

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
newsV4PzpAXk3YBFwLH@jmwa.demon.co.uk...

I read in sci.electronics.design that john jardine
john@jjdesigns.fsnet.co.uk> wrote (in <cjv3hi$87p$1@newsg4.svr.pol.co.u
k&gt about 'Marketing blurb - bullsh*t baffles etc', on Tue, 5 Oct 2004:

Golly, it aint arf fast!

Actually, you're lucky if it IS 'arf as fast as claimed. But it is, no
doubt, much faster than dial-up.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

You're on broadband, yes?.

I was expecting maybe only a 3X improvement on the existing 3kByte/sec. For
me, the big benefit for the extra Ł3 a month was that people could still
ring in while a big PDF is downloading.
It's actually running about 24-34 kByte per second which is nice
regards
john

 

[Dave VanHorn]

Same rules apply to PIC and AVR processors.

Applying crystals properly isn't that hard, but you DO need to read the data
sheet for the crystal.


--
KC6ETE Dave's Engineering Page, www.dvanhorn.org
Microcontroller Consultant, specializing in Atmel AVR

 

[john jardine]

"SioL" <Sio_spam_L@same.net> wrote in message
news:se%8d.3894$F6.1062582@news.siol.net...

"john jardine" <john@jjdesigns.fsnet.co.uk> wrote in message
news:ck1rar$70e$1@news6.svr.pol.co.uk...

nb: The lower frequency PICs seem surprisingly easy to overclock. For
development purposes, I've run 4MHz units quite happily at 25MHz.
regards
john

How about AVR?

SioL

Never had chance to try one :-(

Might change though as I'm getting a bit fed up having to spend hours
figuring out what bit settings mchip have buggered up each time they bring a
new chip out.
I keep reading the AVRs have a cleaner internal design.
(My 'perfect' chip would be something as versatile as the PIC/AVR but run
prog's like a Z80 on whiz)
regards
john

 

[Winfield Hill]

Tom Seim wrote...

Strange, I thought you were in favor of John Kerry. Curious.

No doubt, like me, he's simply strongly against G. W. Bush.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Spehro Pefhany]

On Wed, 06 Oct 2004 09:46:57 -0700, the renowned John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

You can do the reverse: feed back a bit of the ramp voltage into the
guts of the current source such as to increase the current as the ramp
runs. This adds a t-squared term to the curve, nearly compensating
shunt resistance or any other effects that bow the ramp down. I've
done this with 25 ns ramps.

Nice trick.

Reminds me of the old RTD linearization trick. Well, sort of.
John

Sort of.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Winfield Hill]

Ken Smith wrote...

The J201 didn't work for us. We ended up talking Interfet into
producing (selecting) fets for us that are tuned to our need.

You found the J201 family different from the 2N4867 family?
Or did the low-noise screening issue get you? Please provide
more detail. Thanks!

Fusetec looked a little hopeful.
I've also got info coming from Stetron

Consider the issues you have posed. Pass 250mA capability with
a low voltage drop (a volt more or less, which could be inside
the feedback loop), but handle 600V peak. This implies the node
will experience a power level of greater than 0.25 * 600V = 150W
at the beginning of an event, which is clearly too much for small
components unless the time duration is very short, on the order
of milliseconds. This is a simple matter of energy-rate (power)
and thermal mass in the component withstanding the fault voltage.

Your job is to find a way to protect the 600V PTC component, and
to prevent it from overheating as it handles an event. Fuzetec
is not specific: their FHR series says, "keep the time short."

Apparently this business of specifying thermal mass isn't easy, so
manufacturers give you a bit of data. But really Ken, you're on
your own to characterize the part and find an effective way to use
it to buy a few hundreds of valuable microseconds or a millisecond
or two during which to switch to plan B. First, it's your task to
find a reasonable part, and then devise a way to characterize it
for your specific application. Then it's your task to find a way
to best utilize the capabilities of that part, surrounding it with
backup stage-II circuitry to take over the task, with more energy-
capable components, like circuit breakers or mechanical relays.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Mike Monett]

John Larkin wrote:

On Wed, 06 Oct 2004 15:39:12 -0400, Mike Monett <no@spam.com> wrote:

Another issue is that you can't take n-bit data and digitally
correct it to n-bit data without nasty artifacts, missing codes
and ghastly differential linearity.

I'm not sure I understand. A sensor produces analog signals. You
digitize this to whatever accuracy needed, then use a polynomial or
lookup table to get the corrected value. The output is monotonic and
within whatever error tolerance you determine. There are no nasty
artifacts, missing codes or differential nonlinearity problems. So
where's the problem?

How could you possibly take n-bit readings, apply a polynomial
correction, and get n-bit data without missing codes? And how could
you maintain fractional-LSB differential linearity? After all, the
only thing you can do is add or subtract multiples of one LSB.

Sheesh.

John

John,

I really don't understand your objection. Sensor calibration and
linearization is big business. Many sensors are moving the electronics
inside the package to obtain the benefit of improved performance. Your HP
spectrum and network analyzers have the calibration and linearization
routines built-in.

I'm sure you must be thinking of something else, so I compiled a short
list of articles on the topic. Note that I avoided any large pdf files to
save you the download time.

The Changing Role of Software

http://www.sensorsmag.com/articles/0398/da0398/main.shtml

Improve Sensor Linearity and Conformity

http://www.dataforth.com/catalog/doc_834.html

Custom Curve Linearization

http://www.laurels.com/linearizing.htm

Approaches for Compensating Span and Offset in Pressure Sensors

http://www.maxim-ic.com/appnotes.cfm/appnote_number/743

Voltage-to-Range Conversion

http://www.acroname.com/robotics/info/articles/irlinear/irlinear.html

Interfacing with GP2D02 sensors

http://www.barello.net/Papers/GP2D02/

Measuring Air Flow

http://www.kele.com/tech/monitor/Flow/TRAirFlw.html

Does this help?

Regards,

Mike Monett

 

[Winfield Hill]

Tom Seim wrote...

The truth is while these terrorists are still alive oil production
WILL be up and down. But if 40 million Iraq's are against the
terrorists and in favor of oil production they will take care of
these punks in due time.

That's a big if. It appears that 40 million Iraq's want our troops
out of their lives, and couldn't give a damn about oil production.
Short-sighted and ill-advised perhaps, but still...

As for the "terrorists," we see the general populace wildly cheering
every atrocity against our troops. These aren't terrorists, they're
ordinary citizens and arguably some are "freedom fighters," who aren't
about to "take care of these punks in due time," but who are eager to
cheer our withdrawl.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Dirk Bruere at Neopax]

Rich Grise wrote:

On Tuesday 05 October 2004 04:02 am, Reg Edwards did deign to grace us with
the following:


- - - and next year it will be Tehrehan. Then Pyongyang. Then - - -
!

Yeah, the drunken bully never learns from things like Ho Chi Minh City.

They do, but have to be reminded every generation.
BTW, number of 'insurgent' attacks in Iraq in September exceeded 2300.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org

 

[Spehro Pefhany]

On Tue, 05 Oct 2004 17:08:26 GMT, the renowned "Clarence" <no@No.com>
wrote:

I usually do not see Fred's crap. Killfiled you know. SO your reply is the
first I have seen. He hasn't changed his song, nor got a clue.
Fred Boggs is FOS. The Polls show it "TOO CLOSE TO CALL" at this point.
He is simply trying, unsuccessfully, to show Bush being Bushwhacked by the
extreme left. It hasn't happened!

You know if they are running neck and neck, Kerry will have the edge.
;-)

If your considering moving, pack your bags.

My young kid's AAA baseball team just gained a great first baseman.
<shrug> It's always an option.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Boki]

short pin.8 pin.4 work...



"boki" <bokiteam@ms21.hinet.net>
???????:4c3c095a.0410061853.1226ded1@posting.google.com...

Dear All,
I have a portable device that has a 5-V to 0-V pulse output(
without constant frequency, but below 10Hz range), I want this signal
could be detected by PC RS232 port.

I try many connection type, the RS232 still can't detect the device
pulse.

Do we have to design RS-232 handshake circuits with device output to
make the RS232 detect that pulse?

* I don't have to transmit data,just only pulse detection.

Is that baud rate problem? or ? @@


Thank you very much for your help.

Best regards
Boki.

 

[John S. Dyson]

In article <6c71b322.0410061802.6bb3a94e@posting.google.com>,
soar2morrow@yahoo.com (Tom Seim) writes:

xray <notreally@hotmail.invalid> wrote in message news:<n9o6m05djo1kksab3p6urf2h6pus5nudm1@4ax.com>...
On 5 Oct 2004 17:57:22 -0700, soar2morrow@yahoo.com (Tom Seim) wrote:

They can move to the same country that Alec Baldwin moved to after
making the same threat in 2000. I would happily send them brochures.

Toughen up. You are only #3 in the list of right wing clowns here.

No problem, Bill Clinton would be "right wing" amongst you lib wackos.

Actually, Bill Clinton seemed to have less of a policy bias, but instead

was obviously interested in his political legacy. Bill Clinton was
all about gaining power in the American political sense, and had little
apparent interest in left vs. right wing. In essence, he was very
much a chameleon(sp), and his position was based more upon what would
make the listener happy (or making himself look better than reality)
instead of telling the truth. This visceral dyshonesty (sic) of Bill
Clinton would make him have more superficial characteristics of the
AMERICAN left, but he wasn't really as far left wing as the generally
far far left Democrat party.

On the other hand, George W. Bush is almost the opposite, who would
make decisions (or answer questions) that might be popularly unfavorable,
but would be the longer term correct thing to do -- that is, given
available information.

Given the current political situation, George W Bush would cry about
the loss of young American lives based upon their sacrifice and his
responsibility as President... On the other hand, Bill Clinton would
cry in the same situation, because of the imposition of the situation
against his presidency, and the potential negative consequences of his
popularity. The Dems overwhelming belief in their destiny to control
the American populace and maintain political power was evidenced by the
regrets (as mentioned by some Democrats) that they were unhappy that
the attainable 'glory' associated with the 9/11 event would be earned
by George W. Bush instead of bestowed onto the Dems by providence.

My guess is the complex of envy and hatred against George W Bush resulted
mostly from the 1) Fl election fiasco caused by Al Gore's team -- sometimes
causing other individuals to have to behave differently than they prefer,
2) The trust that George Bush has earned, even though he has shown
imperfection, 3) Envy that a Democrat president wasn't in power when
9/11 occured, and anger that the associated FDR type glory wouldn't
possibly be earned by the Democrat (even though the alternative to
Bush would have been more like the demi-communist/weasel Wallace/Gore
instead of a simple man with a reasonable moral compass like Truman/Bush.)
4) The Democrats entitlement mentality that they should be party of
the president. 5) The general mental instability of both the constituents
and the collective Democrat party, where they seem to have the worst
attributes of man.

(For example, breaking (both violence and theft of things like computers)
into another party's headquarters is unacceptable
behavior from any party, but is recently TOO COMMON behavior from the
Democrats, while tending to be the exception to the rule from other parties.
There are idiots on both sides, but the Dems tend to generally even have more
hillbilly type idiots, contrary to the common belief that the GOPers
tend to have lots of 'em. Frankly, both sides have 'em, but the Dems
are generally that way, unless they are viscerally dishonest elites or
maybe even just misled and wayward.)

Another example, the Dems seem to TOO EASILY blur the distinction between
telling incorrect facts and telling lies. Where you'll find MOST OFTEN
that the Dems will KNOWINGLY tell a lie (e.g. 200Million instead
of 120Million, yet an OBVIOUS telling of
unknowingly incorrect facts by ANYONE ELSE (or facts that have become
questionable) is deemed by Dems to be equvalent to the common Democrat
(often leftist) character flaw of deception. This is a way of cheating,
where an incredibly dangerous Democrat character/judgement flaw is implied
to be equivalent to a truly honest judgement or claim based upon unknowingly
incorrect data. (It is true that the flawed intelligence data is just
as dangerous as the general character and integrity flaws of the Dems,
but the weakened intellegence agencies were mostly damaged by Democrat
policies anyway... :-().

(Frankly, there are good Democrats available, but they seldom run
for the presidency -- e.g. Evan Bayh. Evan tends to spin his politics
to be more centrist than they really are, but he isn't too darned bad
when compared with Kerry -- who is a flaming leftist, and generally
the farthest left Senator.)

There are definitely alot of flaws on the right also, but the prominent
American leftist party (the Democrats) would be laughable if they weren't so
dangerous and some people actually take them seriously.

John

 

[John S. Dyson]

In article <20041004184910.22356.00001480@mb-m16.aol.com>,
rolavine@aol.com (Rolavine) writes:

From: Spehro Pefhany

Long article in the NYT here:
http://www.nytimes.com/2004/10/03/international/middleeast/03tube.html

They were just 7075-T6 aluminum, which is pretty common stuff in the
aircraft industry (also used for making bicycle frames etc.). The
technical information is unusually detailed for a newspaper article.

It's pretty clear now that the Bush Admin made up the Iraqi threat and it's
related documentation,

Please provide references to the fact that Putin didn't warn Bush about

Saddam's intent. Please provide references to the fact that the CIA
(and other intelligence agencies) weren't seriously damaged by mostly
Democrat policies, including during the Clinton administration/screwup.

John

 

[Travis Hayes]

"john jardine" <john@jjdesigns.fsnet.co.uk> wrote in message
news:ck21po$irl$1@news8.svr.pol.co.uk...

"John Todd" <tser827@yahoo.com> wrote in message
news:Xns9579465772802tser827yahoocom@129.250.170.84...
John Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote in news:qGZ
$nVMQpXYBFwrm@jmwa.demon.co.uk:

I read in sci.electronics.design that Rich Grise <null@example.net
wrote (in <rKa8d.4134$eq1.3864@trnddc08&gt about 'Is this antenna
article serious?', on Mon, 4 Oct 2004:


I thought you meant that there was a specific reference to a Bussard
ramjet.


For a really great story concerning a Bussard engine,
read Poul Anderson's "Tau Zero"!

I lost my copy of it maybe 30 years ago but somewhat annoyingly I've been
stuck with an oft remembered but very hazy memory of a described spaceship
data encoding system that compressed vast amounts of data into maybe just
6
transmitted digits. The decoding and unzipping back on earth apparently
took phenomenal time and computer power.
Any idea if this the same book?.
I'd love to reread and actually *understand* what Poul was on about .
regards
jhon

You are thinking of "Gold at the Starbow's End", by Fredrick Pohl. The
process described was called "engodelization", I suppose after Godel. The
back-of-envelope version of this concept is to represent each character as a
prime number, then send back the product of the primes. The receiver has to
factor the received data to recover the primes used. For example, if I sent
the number 2040, you would factor it to see that I sent 2 2 2 3 5 17, and
then figure out what I meant with those 6 numbers.