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PICList Thread
'Muscle Wires(R) FAQ (fwd)'
1994\11\30@172644 by crocontroller discussion list

PIC Users,

       In response to several questions about Muscle Wires I have
forwarded a copy of the latest FAQ file from Mondotronics, the company
that makes them.  Roger Gilbertson, the president, makes his e-mail
address available for other questions.  It is in the FAQ.

       Have fun,

Martin Kirk
Arizona State University
spam_OUTmlkTakeThisOuTasu.edu
(602) 263-9270

---------- Forwarded message ----------
Date: Tue, 29 Nov 1994 19:38:11 -0800
From: Roger G. Gilbertson <.....mondoKILLspam@spam@mondo.com>
To: mlkKILLspamasu.edu
Subject: Muscle Wires(R) FAQ

Hello Martin -

Thank you for your interest in our Muscle Wires(R) products. Here's our
latest Muscle Wires Frequently Asked Questions file. We also have a product
flyer as a separate email file. Please request it from us if you have not
received it already.

If you provide us with your postal address we will send you our printed
version (with photos) and keep you informed with future mailings.

Thanks again for your interest!

Roger G. Gilbertson
President

    /\  /\  /\
   //\\//\\//\\     Mondo-tronics, Inc.          Phone 415-455-9330
/////  //  //  ///// 524 San Anselmo Ave #107-20    Fax 415-455-9333
   \\//\\//\\//     San Anselmo, CA 94960        email .....infoKILLspam.....mondo.com
    \/  \/  \/      USA                     Order Line 800-374-5764

======================================================================

           MUSCLE WIRES - FREQUENTLY ASKED QUESTIONS
                           email V10


Q: What are Muscle Wires?

A: Muscle Wires are thin, highly processed strands of a nickel-titanium
alloy called nitinol - a type of Shape Memory Alloy that can assume
radically different forms or "phases" at distinct temperatures.


Q: How do Muscle Wires work?

A: At room temperature Muscle Wires are easily stretched by a small force.
However, when conducting an electric current, the wire heats and changes to
a much harder form that returns to the "unstretched" shape - the wire
shortens in length with a usable amount of force.


Q: How much do Muscle Wires shorten?

A: Muscle Wires can be stretched by up to eight percent of their length and
will recover fully, but only for a few cycles. However when used in the
three to five percent range, Muscle Wires can run for millions of cycles
with very consistent and reliable performance.


Q: How strong are Muscle Wires?

A: Large wires are stronger than small ones, and strength varies with
diameter. The strength to expect from a wire when heated is shown by the
Recovery Weight in the table below.

The Deformation Weight indicates the amount needed to stretch a wire when
cool - about one sixth the force exerted when the wire is heated. Our
largest wire has over 45 times the strength of the smallest size, so you
can easily match wire strength to your needs.


Q: What if I need more strength?

A: For more strength, use two or more wires in parallel. This gives you as
much strength as needed, and still keeps the fast cycle times of smaller
wires.


Q: How fast can Muscle Wires activate?

A: Muscle Wires contract as fast as they are heated - in one thousandth of
a second or less. To relax, the wire must be cooled, which depends on the
conditions surrounding the wire, and its size. Our new Flexinol HT series
of wires has a higher transition temperature and cools up to 50% faster
than the LT wires. The table below gives typical cycle rates for both LT
and HT wires in still air. Moving air or immersing the wires in a fluid
like a water/glycerine mixture can increase these by ten times or more.


Q: How much power do Muscle Wires use?

A: The power needed to activate a wire depends on its diameter, length, and
the surrounding conditions. The table below gives typical current levels
for "room temperature" conditions. Power can be increased, but once the
wire has fully shortened, power should be reduced to prevent overheating.

-----------------------------------------------------------------
           Table 1.  Flexinol Muscle Wire Properties
-----------------------------------------------------------------
              Wire    Linear  Typical  Deform. Recovery  Typical
Wire       Diameter    Resist. Current  Weight*  Weight*   Rate**
Name       (microns)  (ohm/m)     (mA) (grams)   (grams)  (LT/HT)
-----------------------------------------------------------------
Flexinol 037     37       860       30       4       20    52/68
Flexinol 050     50       510       50       8       35    46/67
Flexinol 100    100       150      180      28      150    33/50
Flexinol 150    150        50      400      62      330    20/30
Flexinol 250    250        20    1,000     172      930     9/13
-----------------------------------------------------------------
  * Multiply by 0.0098 to get force in Newtons
 ** Cycles per minute, in still air, at 20 Centigrade
    LT = low temp 70 degrees C, HT high temp 90 degrees C
-----------------------------------------------------------------


Q: How long do Muscle Wires last?

A: When used in the three to five percent range under proper conditions
Muscle Wires can run for millions of cycles. Often, other parts of a device
will fail or need adjusting long before the Muscle Wire does.


Q: What are the advantages of Muscle Wires?

A: Compared to motors or solenoids, Muscle Wires have many advantages:
small size, light weight, low power, a very high strength-to-weight ratio,
precise control, AC or DC activation, low magnetism, long life, and direct
linear action.

These features let you create whole categories of amazing new devices that
would be difficult or impossible with anything other than Muscle Wires.


Q: What are the keys to using Muscle Wires?

A: For longest lifetimes and best performance from your Muscle Wire
devices, follow these key points:

  * Have good electrical & mechanical connections.
  * Protect the wire from overheating.
  * Protect the wire from overstraining.

Each of these can be accomplished in many different ways. These topics and
more are covered in detail our new 128 page "Muscle Wires Project Book".

For more on this book and all our other products, see our Muscle Wires
Products flyer. Please request it if you have not received it already, and
contact us with any further questions you may have. Thanks again!

    /\  /\  /\
   //\\//\\//\\     Mondo-tronics, Inc.          Phone 415-455-9330
/////  //  //  ///// 524 San Anselmo Ave #107-20    Fax 415-455-9333
   \\//\\//\\//     San Anselmo, CA 94960        email EraseMEinfospam_OUTTakeThisOuTmondo.com
    \/  \/  \/      USA                     Order Line 800-374-5764

======================================================================
Legal. (C)1994 Mondo-tronics, Inc. Muscle Wires is a registered
trademark of Mondo-tronics, Inc. so please use it with the
M and the W capitalized. Eat your vegetables. :(*)

E-FAQ V10.1
9411.01

I think that 50VDC will be reasonably safe so long as it's
indoors, in a dry area, and the voltage is not referenced to
earth ground. Put whatever protection you can around the area
to reduce the chance of people grabbing things.

That said, I think there's a significant chance of injury
due to *thermal* burns. That Nitinol wire gets pretty hot,
as I recall, and there should be enough power dissipated to
give somebody a nasty burn. You're more likely to have trouble
due to this than from electric shock. Remember McDonald's
and the infamous 'hot coffee' lawsuit!

Why would you want art lovers to touch this thing anyway? Those
wires aren't very rugged, and the first ham-handed six-year-old
that gets close will destroy it in seconds. And probably think
it's funny, too.......

forbesmspam_OUTpeak.org   KC7LZD
Mark G. Forbes
"Never ascribe to malice that which can be blamed on the engineer."

1995\11\09@043913 by Errington A

A range of 3wire displays are made by III-V systems, and stocked by Farnell
in the UK.  They include 2 digit and 4 digit 7seg displays in red and
green.

They are all based on the MM5450N display driver chip, which takes 34 serial
data bits in on the 3 wire interface and controls 34 LED segment drivers.

Andy
---------------------------------------------------------------------
Andrew M Errington                               Tel: +44 1524 593678
Microcomputer Consultant                         Fax: +44 1524 844011
Lancaster University                      @spam@a.erringtonKILLspamlancaster.ac.uk
Lancaster LA1 4YW     www.lancs.ac.uk/people/cpaame/cpaame.htm
---------------------------------------------------------------------

>Does anyone know where I can purchase LT8522 led display referrenced in
>AN592? Is there a "better" device? I'm looking for any serial led display
>with at least 3 seven seg. displays and built in logic/latches for serial
>interface.  Thanks, Eric Seeley

1995\11\09@082624 by Warren Crossfield

Eric;

   Here's one used the other day...worked without any trouble at all!


   MAXIM MAX7219CWG-ND  (That's the Digi-Key part# for the SO-24 part)

   $8.27 ea.

   Serial input 8 digit LED Driver Multiplexed.


cheers.



                                           -Warren
_______________________________________________________________________________
Subject: 3 WIRE LED DISPLAY
From:    e_seeley%KILLspamOWENS.RIDGECREST.CA.USKILLspamprdnet.polaroid.com at INET
Date:    11/8/95  9:45 PM

Does anyone know where I can purchase LT8522 led display referrenced in
AN592? Is there a "better" device? I'm looking for any serial led display
with at least 3 seven seg. displays and built in logic/latches for serial
interface.  Thanks, Eric Seeley

1995\11\10@122829 by Preben Granberg

'Re : 3 wire LED display (well 2 wire)'
1995\11\10@131535 by Robin Abbott

I suggest that an excellent device for 2 wire I/O expansion is the
M5450. This offers 34 output bits clocked in on a data and
clock line, the outputs only being transferred on the last
clock. It's perfect for up to 4, seven segment displays,
driven on a non-mux basis, good for other apps as well !

Robin

RemoveMErobin.abbottTakeThisOuTdial.pipex.com

1995\11\10@140006 by reginald neale

1996\06\30@040928 by Lee Jones

Hi Neil,

> I have an application where I want to send half duplex serial data between
> two PIC 16c74 microcontrollers through a one wire link (+ gnd of course))
> The thoroughput required is 32 bits of data (the value of 4 registers)
> needed to be sent 30 times per second

Since you want to send 4 octets (32 bits) 30 times per second, anything
at or above 1200 baud would suffice.  If you're going to put any sort of
checksum on each "packet", you might want to use 2400 baud.  Generally,
the slower the link, the less noise susceptibility.

Depending on the distance between the PICs, you might be able to get
away with TTL signal levels between the devices.  I'd use that for a
link up to several feet.  Beyond that distance, a differential signal
such as RS-422, RS-423, or RS-485 would work well.  Driver chips are
easier than RS-232 since they use lower, single ended voltage swings.
And you have control both the physical interface on both ends.

> I want to keep this simple. I don't want to start playing with
> UARTS and USARTS, even though a USART is built into the PIC (its
> seems quite complex for a beginner like me) and a one line link
> (asynchronous) is a must. Perhaps someone could suggest a simpler
> method.

Bite the bullet and learn about UARTs.  There's a reason that UART
stands for Universal Asynchronous Receiver Transmitter.  It does the
octet parallel to time dependant bit serial data conversion that you
say you want for this project.  If you find a chip by another name
that does the same function, you're deluding yourself if you think
you're not working with a UART/USART.

You can still get external UARTs that are programmed totally with
jumpers (i.e. no software setup).  The interface is 8 bit parallel
with a couple more lines for handshaking.  If you have enough pins
free on the PICs you're using, one end can write octets and the
other end can read octets.  Nothing simpler.

                                               Lee

-------------------------------------------------------------------
Jones Computer Communications             spamBeGoneleespamBeGonefrumble.claremont.edu
509 Black Hills Dr, Claremont, CA 91711         voice: 909-621-9008
-------------------------------------------------------------------

1996\06\30@141604 by james

1996\06\30@172221 by Neil Gandler

1996\07\03@123410 by Byron A Jeff

1996\07\03@143635 by Kalle Pihlajasaari

Hi,

> Typical of handshaked parallel transfers between devices like printer ports
> and whatnot.
>
> So the transmit protocol for each is:
>
> 1) Check other handshake line and make sure its inactive.
> 2) Place your data and Assert your handshake line.
> 3) Wait for the other to assert it's handshake.
> 4) Remove data and de-assert your handshake.

Reminicent of EI, EO two wire interrupt controller daisychaining.

Have a look at a Zilog data book and use the method described
somewhere in there.  The devices have an effective master and slave
flavour but in your case it won't matter as the 'bus' will be
released regularly.  Basicly the 'slave' chip asks for permission
and receives it if the master is available at other times the
master waits for the slave to ACK after a request.  It is easier
to leave the connection tilted in one direction when idle if there
is bandwidth as there cannot be the deadlock you mention.

> The problem is a deadlock occurs if both are in sync and both do (1) and (2)
> at the same time. Talk about blown buffers! Even if the actual transfer
> is preceeded with a null handshake both will proceed.

Place a 1kOhm resistor in series and the blown buffer will be avoided.

Cheers
--
Kalle Pihlajasaari     TakeThisOuTkalleEraseMEspam_OUTdata.co.za
Interface Products     Box 15775, Doornfontein, 2028, South Africa
+27 (11) 402-7750      Fax: +27 (11) 402-7751

1996\07\03@152527 by Norm Cramer

1996\10\03@032606 by Herve Cousin

At 22:19 02.10.96 -0400, you wrote:
>Hello,
>I need to implement a SPI, QSPI or Microwire interface with a pic16cxx
>and was wondering if anyone had any information/source code on it?
>Thanks for the help.
>
>
Hi Gerry,

Have a look at the application notes-page of Microchip, especially under
"Serial EEPROMS TUTORIALS AND APPLICATION NOTES" with SPI and IIC (with
source code):

http://www.microchip2.com/appnotes/appnotes.htm

Regards,

Herve
Herve R. Cousin - Inorganic Analytical Chemistry,
Federal Institute of Technology (ETH-Z)
CH-8092 Zurich, Switzerland
Tel.:    + 41-1-632-4472, Fax:     + 41-1-632-1090,
RemoveMEcousinTakeThisOuTinorg.chem.ethz.ch, http://www.analytica.ethz.ch/cousin.html

1996\10\03@195604 by Gael Waiche

'Fire alarms and 2 wires methode'
1996\10\07@105101 by vador Eduardo Tropea (SET)

Hi everybody:

 I'm serching information about the following topics:

1) What norms must comply a fire alarm in USA and Europe?
2) What's the protocol used for two wires smoke & fire detectors? These
detectors use 2 wires for power supply & comunications, all connecteds in a
ring.

 I'm implementing an anti-fire & anti-asalt alarm with two PICs (16C62A &
16C84) but I want to make it better and expandable.
 Any pointer would be appreciated.

bye SET.

********************************************************************************
Salvador Eduardo Tropea (SET) - salvadorEraseME.....inti.edu.ar
Work: INTI (National Institute of Industrial Technology) Sector: ICE
(Electronic Control & Instrumentation)
Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina

1996\10\07@121530 by Ian Stirling

>
> Hi everybody:
>
>   I'm serching information about the following topics:
>
> 1) What norms must comply a fire alarm in USA and Europe?
> 2) What's the protocol used for two wires smoke & fire detectors? These
> detectors use 2 wires for power supply & comunications, all connecteds in a
> ring.
>
>   I'm implementing an anti-fire & anti-asalt alarm with two PICs (16C62A &
> 16C84) but I want to make it better and expandable.
>   Any pointer would be appreciated.
>

Well, for the european market, you'll need to get it CE marked, and comply
with any local regulations. CE marking covers a lot of feilds, from
EMC emmission/acceptance, to electrical safety, .....
It can't be sold in europe, if not CE marked, look for info on the
web on altavista, using CE NEAR precompliance


> bye SET.
>
>
*******************************************************************************
*
> Salvador Eduardo Tropea (SET) - EraseMEsalvadorinti.edu.ar
> Work: INTI (National Institute of Industrial Technology) Sector: ICE
> (Electronic Control & Instrumentation)
> Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina
>


--
Ian Stirling.                        |  http://web.students.stir.ac.uk/~is06
AKA Caeser, Bolonewbie.              |  Pretty sad at the moment, should get
                                    |  better tho.

1996\10\07@121541 by brooke

1996\10\07@132027 by John Payson

1996\10\08@084324 by vador Eduardo Tropea (SET)

This mail is related to the fire alarm question:

Some body said
>> It is my understanding that conventional (non digital) fire alarm
>> systems
>> use two wires that run from the controller and are terminated at the far
>> end with a resistor.  The current is used as a check to see if the wires
>> have opened.  If there is an open circuit, the alarm sounds a trouble
>> alarm.
>> The fire sensors are paclaced across these two wires and if a sensor
>> detects
>> a fire it shorts the wires.  You can see that if a fire broke out along
>> the
>> wires it might melt the insulation and short the wires also giving a
>> fire
>> alarm.  Some fire sensore require 12 VDC power so another 2 wires are
>> used
>> to provide the power for the sensors that require power.

and another replayed

{Quote hidden}

>Hmm... I don't know about fire alarms, but I've seen other applications
>in which devices sat on two wires, drawing power (not outrageous current)
>and when one needed to send a signal, it would increase its current
>consumption dramatically but not totally short out its wires.  A simple
>example of such a scheme would be a bunch of PICs running off 7805's,
>each with 220-ohm resistors from some port pins to Vdd, with all of these
>devices running off a weak 12-volt supply (say, 22 ohms series resistance)
>with a strong 9v supply underneath it.  If no PICs turn on their grounding
>resistors (and they don't otherwise use too much current) the supply should
>sit a little under 12v.  If the supply goes all the way up to 12 or down to
>9v, however, there's a problem.

Thank you guys, but I'm searching for a protocol, for example NOTIFIER can put
99 fire-detectors in a ring of 2 wires across a building and notify which of
the 99 detectors is active.

SET.
********************************************************************************
Salvador Eduardo Tropea (SET) - RemoveMEsalvadorEraseMEEraseMEinti.edu.ar
Work: INTI (National Institute of Industrial Technology) Sector: ICE
(Electronic Control & Instrumentation)
Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina

1996\10\08@133058 by Brooke

1996\12\03@184429 by Steve Hardy

> From: Mayes uk <RemoveMEmikespam_OUTKILLspamD-M-G.DEMON.CO.UK>
>
> Hi,
>
> I have looked around and found lots of code to implement
> I2C master PICs, but I haven't found any code for
> bit banging I2C slave.
>
> Is there an ANxxx covering this?
> Has anyone got some code they could e-mail me, or pointer
> to some code?

As I mentioned in a previous post, the timing requirements for the I2C
slave even at 100KHz are too severe for a software implementation.
This is why the 16CXX series implement a slave I2C in hardware, but
leave the master implementation to software.

The reason for this disparity is that the master drives the clock line,
whereas the slave has to follow the clock and respond if necessary
within quite tight timing constraints.

This problem may be mitigated somewhat if you are writing both master
and slave.  In this case, the master can be aware that the slave is
slow and thus relax its clock rate to, say, 10KHz.  Strictly speaking,
it is no longer an I2C slave, but may well be good enough for the
application.

Regards,
SJH
Canberra, Australia

1996\12\03@192425 by ang (Chee Foon Tiang)

On the contrary, a bit-banged I2C slave is possible to be
implemented.

What you need is a start condition detection circuit which
can be be implemented using cheap 74HCTxx logics.

If interested, please e-mail me.
And sorry, as I do not have the PIC codes.
I have a big-banged 100kHz slave on a 4-bit Hitachi's
microcontroller.


Regards,

Peter Tiang
RemoveMEtiangcfoonTakeThisOuTspamhitachi.com.my

{Quote hidden}

>> From: Mayes uk <EraseMEmikespamspamBeGoneD-M-G.DEMON.CO.UK>
>>
>> Hi,
>>
>> I have looked around and found lots of code to implement
>> I2C master PICs, but I haven't found any code for
>> bit banging I2C slave.
>>
> Is there an ANxxx covering this?
> Has anyone got some code they could e-mail me, or pointer
> to some code?
>
>Is I mentioned in a previous post, the timing requirements

for
{Quote hidden}

>the I2C
>slave even at 100KHz are too severe for a software
>implementation.
>This is why the 16CXX series implement a slave I2C in
>hardware, but
>leave the master implementation to software.

>The reason for this disparity is that the master drives the
>clock line,
>whereas the slave has to follow the clock and respond if
>necessary
>within quite tight timing constraints.

>This problem may be mitigated somewhat if you are writing
>both master
>and slave.  In this case, the master can be aware that the
>slave is
>slow and thus relax its clock rate to, say, 10KHz.  Strictly
>speaking,
>it is no longer an I2C slave, but may well be good enough for
>the
>application.

>Regards,
>SJH
>Canberra, Australia

'Philips 3-wire (Data, Strobe and Acknowledge) prot'
1996\12\13@215918 by ang (Chee Foon Tiang)

1996\12\14@004041 by Todd Peterson

'Microchip's I2C license (was: "Re: Philips 3-wire '
1996\12\14@060204 by fastfwd

Todd Peterson <RemoveMEPICLISTKILLspamMITVMA.MIT.EDU> wrote:

> I am looking at doing a project using Philips I2C Bus and, through
> a series of phone calls, happened to end up talking with the
> Philips in-house patent attorney about it.  He told me some news
> that disturbed me:  he said, and I paraphrase fairly close to the
> original - ' I won't say thay Microchip is breaking the law using
> I2C YET, but they do not have a valid license.' .... I, of course,
> contacted MCHIP and they told me they DID have a license.
> ....
> Anyone know for sure why I was told by Philips that Microchip was on
> their bad list?

Todd:

No, don't get your hopes up... I don't know what's going on, either.

Here's everything I DO know about Microchip, Philips, and the I2C
license.  I've divided it into "good" and "bad" categories, but
beyond that, it's completely disoganized... I'm too tired to try to
put these points into any meaningful order:

BAD:

   1.  When Microchip first started making I2C EEPROMs, the term
   "I2C" was conspicuously absent from all of their documentation,
   as was any acknowledgement that the protocol was owned by
   Philips.

   2.  I don't know how the I2C licenses are written; if they
   differentiate between "dumb" devices like EEPROMs and "smart"
   devices like microcontrollers, Microchip may have stepped on
   their toes by incorporating I2C (even though it's only Slave
   Mode) into the PICs.

   3.  Microchip's microcontrollers don't implement Master Mode in
   hardware, but Microchip advertises them as containing a
   Synchronous Serial Port "with I2C".  Maybe Philips doesn't like
   that.

   4.  Microchip has traditionally taken a too-casual approach to
   trademarks; the "Pro Master" programmer had to be renamed "Pro
   Mate" when it was discovered that the name was already taken,
   and even the word "PIC" can't be used in any of Microchip's
   development tools, since it's trademarked by a European company.
    Maybe they used the I2C trademark inappropriately, too... I
   don't know.

GOOD:

   1.  In general, Philips seems willing to license the I2C
   protocol to just about ANYONE... As you mentioned, there are AT
   LEAST 15-20 licensees.

   2.  Microchip Technology is a member of the ACCESS.bus Industry
   Group, and ACCESS.bus uses the I2C protocol.  By supporting
   AbIG, Microchip is supporting Philips.

   3.  All the current literature acknowledges that I2C is a
   Philips trademark, and the Microchip databooks even reference
   the Philips "I2C and how to use it" spec.

   4.  Microchip is now #2 worldwide in serial-EEPROM sales
   (behind -- WAY behind, by the way -- SGS-Thomson).

Ok... That's it.  Sorry I didn't have any specific information for
you.

-Andy

=== Andrew Warren - fastfwdSTOPspamspam_OUTix.netcom.com                 ===
=== Fast Forward Engineering - Vista, California          ===
===                                                       ===
=== Custodian of the PICLIST Fund -- For more info, see:  ===
=== http://www.geocities.com/SiliconValley/2499/fund.html ===

 I'm trying to find the Schottky diodes used in the 12v real all
circuit used to interface serial ports to Dallas one wire devices
(Dallas app note 74). Its an ERA-82-004, and I can't find it, or a
cross refrence anywhere.

 On a PIC related note: I've been designing a PIC based interface to
the DS1820 temperature sensors for the last couple of weeks in my
spare time. It has a 2k eeprom for serial number storage, max232 for
rs232 interface, and uses a LP2950 to regulate the power from the
RS-232's DTR and RTS lines. I was planning one producing these and
selling them for about $60, including 2 sensors. The purpose was to
take the load off the computer (and so that it would work under a
multitasking enviornment like Linux or Win95).

 But I forgot something. I had read app note 74 a long time ago, and
I knew that you could use the serial port to directly talk to the
devices, but I forgot about it. No I know that my device really isn't
needed, and that it can all be done in software on the host, with 4
diodes and a resistor.

 Needless to say - when you charge ahead on a project don't forget to
do your research first. At least I hadn't gone so far as to get boards
produced yet <G>.

 Brian

---
 Nexus Computing        spamBeGonenexusSTOPspamEraseMEeskimo.com        http://www.eskimo.com/~nexus
 The Islet BBS       FidoNet by PPP dialup                     (206)927-9219
 Brian Lane       embedded systems programmer                         KC7TYU

'wirewrap tools'
1997\01\12@123053 by VENKATARAMANI B.(ECE)

Our students are interested in doing Microcontroller based projects.
Since the time available for the project is limited, a simple batch
of students may not be able to end up with a finished, well proven
product. Hence we would like a no. of batches to carry out the work
to achieve them . For this purpose, wirewraping the circuit, I feel
would be ideal.
   Towards this end, we would like to procure wirewrap tools (both
machine operated and manually operated) for wrapping as well as
unwrapping,
wires for wraping and so on. Can you please send me the addresses of
the companys (including their Fax no.s) who are manufacturing these
tools. Please send this information personally to me.
Thanking You,
With regards,
Dr.B.Venkataramani,
Asst. Professor,
E.C.E. Dept.,
Regional Engg. College,
Tiruchirappalli-620 015
INDIA
----------------------------------
email:KILLspambvenkispamBeGonerect.ernet.in
----------------------------------

'wirewrap tools -Reply'
1997\01\12@200954 by Chee Foon Tiang

Wirewrapping is expensive, not the tools itself
but the cost of the IC sockets (with wire-wrap
turned-pins) is going to kill you.
However, it is very reliable and I trust it more
than soldering which gets exponentially trickier as
your pin count grows.

If you insist, check out RS International or Farnell
both from the UK but has world-wide operations.
I think UK PICers can provide you with the contact
number.


{Quote hidden}

>Our students are interested in doing Microcontroller
>based projects.
>Since the time available for the project is limited, a
>simple batch
>of students may not be able to end up with a finished,
>well proven
>product. Hence we would like a no. of batches to carry
>out the work
>to achieve them . For this purpose, wirewraping the
>circuit, I feel
>would be ideal.
>    Towards this end, we would like to procure
>wirewrap tools (both
>machine operated and manually operated) for wrapping
>as well as
>unwrapping,
>wires for wraping and so on. Can you please send me
>the addresses of
>the companys (including their Fax no.s) who are
>manufacturing these
>tools. Please send this information personally to me.
>Thanking You,
>With regards,
>Dr.B.Venkataramani,
>Asst. Professor,
>E.C.E. Dept.,
>Regional Engg. College,
>Tiruchirappalli-620 015
>INDIA
>----------------------------------
>email:EraseMEbvenkiEraseMErect.ernet.in
>----------------------------------

1997\01\12@201623 by Gerry Smith

1997\02\10@032029 by Gvran Mvrk

1997\02\10@081537 by Luigi Rizzo

> > I need to link(RF or microwave) two 16c84's for one-way serial coms.
> > Range only needs to be ~ 5 ft, baud => 1200.  I would prefer a single
> > chip if possible with no external inductor, preset frequency is fine.
> > Could someone point me in the right dirrection?     Thanks, Dave Ebsen.
> What about 300 THz? (Infrared). Siemens, Temic, Novalog, Rohm and HP has
> transcievers fulfilling your requirements.

have you tried to get them in less than 10K quantities (of course, not
bundled in some high-price product which uses them)

       Luigi
-----------------------------+--------------------------------------
Luigi Rizzo                  |  Dip. di Ingegneria dell'Informazione
email: @spam@luigi@spam@spam_OUTiet.unipi.it    |  Universita' di Pisa
tel: +39-50-568533           |  via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522           |  http://www.iet.unipi.it/~luigi/
_____________________________|______________________________________

1997\02\10@123604 by Zack Cilliers

Hi there!

Have a look at this site rfsolutions.co.uk/rf_prods/rf_prods.html
I am sure this is what you are looking for.

Zack
spamBeGonezcKILLspampixie.co.za
There is no justice.
There is just us.

----------
> From: D. and S. Ebsen <.....ebsendsmspam_OUTINAV.NET>
> To: TakeThisOuTPICLIST.....TakeThisOuTMITVMA.MIT.EDU
> Subject: WIRELESS LINK FOR 2 PICS
> Date: Monday, February 10, 1997 9:51 AM
>
> I need to link(RF or microwave) two 16c84's for one-way serial coms.
> Range only needs to be ~ 5 ft, baud => 1200.  I would prefer a single
> chip if possible with no external inductor, preset frequency is fine.
> Could someone point me in the right dirrection?     Thanks, Dave Ebsen.

1997\02\10@145957 by radyan

1997\02\11@030335 by Gvran Mvrk

Luigi Rizzo wrote:
>
> > > I need to link(RF or microwave) two 16c84's for one-way serial coms.
> > > Range only needs to be ~ 5 ft, baud => 1200.  I would prefer a single
> > > chip if possible with no external inductor, preset frequency is fine.
> > > Could someone point me in the right dirrection?     Thanks, Dave Ebsen.
> > What about 300 THz? (Infrared). Siemens, Temic, Novalog, Rohm and HP has
> > transcievers fulfilling your requirements.
>
> have you tried to get them in less than 10K quantities (of course, not
> bundled in some high-price product which uses them)
>
>         Luigi
> -----------------------------+--------------------------------------
> Luigi Rizzo                  |  Dip. di Ingegneria dell'Informazione
> email: TakeThisOuTluigiKILLspamspamiet.unipi.it    |  Universita' di Pisa
> tel: +39-50-568533           |  via Diotisalvi 2, 56126 PISA (Italy)
> fax: +39-50-568522           |  http://www.iet.unipi.it/~luigi/
> _____________________________|______________________________________
Farnell Components (http://www.farnellcomponents.com) lists the HP
HDSL-1000 at approx.7USD in single quantities. The Temic and Siemens
parts TFDS4000 and IRM3105 are better, and I'm sure you could find
distributors also for these parts.
Goran Mork

1997\02\12@042511 by lmclaren

D. and S. Ebsen wrote:
>
> I need to link(RF or microwave) two 16c84's for one-way serial coms.
> Range only needs to be ~ 5 ft, baud => 1200.  I would prefer a single
> chip if possible with no external inductor, preset frequency is fine.
> Could someone point me in the right dirrection?     Thanks, Dave Ebsen.

Can you get Elektor magazine, There are a nubmer of ads for wirless
modems etc.

--
Lee McLaren                          .....lmclarenRemoveMEtrumpet.com.au
Comstra pty. ltd.                    RemoveMElmclarenspamBeGonecomstra.com.au
2 Kirksway place                     phone       03 62244488
Hobart Tasmania                      fax         03 62244601
Australia 7000                       mobil       018 138682

'It was five hours of Boggs's "channelling". After three hours
I asked him to summon up the soul of Jimi Hendrix and requested
All Along the Watchtower. You know, the guy's been dead
twenty years but he still hasn't lost his edge'
Mulder

 I am trying to use the DS 1820 digital thermometer from Dallas
Semiconductors with a PIC16C84 but I can't read the correct temperature.

 I also have tried the Steve Marchant program for interfacing the DS1820
with PIC16C84. The only temperature that i read is 3.5 degrees Celsius.

 Has anybody used this device with 16c84?

 Thanks for any insight you can offer.


----------------------------

Athanassios Mavrogeorgiadis
  Electrical Engineer
 spamBeGonetmav@spam@spam_OUTtitan.ee.auth.gr

----------------------------

1997\05\14@085540 by johan.haglow.1359

Athanassios Mavrogeorgiadis wrote:
>
>   I am trying to use the DS 1820 digital thermometer from Dallas
> Semiconductors with a PIC16C84 but I can't read the correct temperature.
>
>   I also have tried the Steve Marchant program for interfacing the DS1820
> with PIC16C84. The only temperature that i read is 3.5 degrees Celsius.
>
>   Has anybody used this device with 16c84?
>
>   Thanks for any insight you can offer.
>
> ----------------------------
>
> Athanassios Mavrogeorgiadis
>    Electrical Engineer
>   TakeThisOuTtmavspamtitan.ee.auth.gr
>
> ----------------------------
Hi
I have used the DS1820 with 484 without any problems just take care of
the timing limits in the  datasheets. I have code for interfacing with
three different DS1820 att the same time and display it on a LCD. I
don't have it with me right now but i can send it to you if you
want.just send me a mail. If you have an oscilloscope try to check if
you have right signals out.
                                       Johan

'1 or 3 Wires Keyboard ?!?'
1997\05\27@235216 by senna

'1-wire bus'
1997\05\30@060952 by FrankT

1997\05\30@061825 by David BALDWIN

1997\06\02@115450 by David BALDWIN

'Pics and wire-wrapping..'
1997\06\10@205643 by Ravindra Divekar

1997\06\10@231645 by Reginald Neale

1997\06\10@232053 by Sean Breheny

1997\06\11@004029 by William Chops Westfield

1997\06\11@073300 by Andy Kunz

1997\06\11@094143 by Byron A Jeff

1997\06\11@150659 by Leon Heller

In message <9706102342.AA14448EraseMEshakti.hal.com>, Ravindra Divekar
<RemoveMEravindraEraseMEspam_OUTHAL.COM> writes
>Hi folks!
>this is my first attempt at making a
>wire-wrapped board.
>
>Please tell me:
>do we need to use special IC sockets, if so,
>what are they called?
>how much do wire-wrapping tools cost ?
>
>has anybody used a bread-board for prototyping a PIC ?

The sockets are just called "wire-wrap sockets", you do need special
ones. A hand tool costs a few $s, I'd start with one of these, rather
than a power tool.

Leon
--
Leon Heller
Amateur radio callsign: G1HSM
Email: @spam@leonRemoveMEEraseMElfheller.demon.co.uk http://www.lfheller.demon.co.uk
Tel: +44 (0) 118 947 1424 (home) +44 (0) 1344 385556 (work)

1997\06\12@002634 by Richard Adamec

'wire wrapping'
1997\06\12@042532 by Tim Forcer

Few comments, please ignore if you've heard it/them already.

1.  I'd invest in a "proper" wire-wrap stripper such as those made by CK in
Germany (mine for 30 AWG = 0.25mm is part number 3756).  The built-in
stripper in the 3-in-one tool gets irksome when doing a lot of wrapping.
Proper tool also makes it easy to get the length of stripped wire absolutely
right.

2.  When wrapping a daisy chain connection such as a data bus or clock line,
don't go a>b, b>c, c>d etc.  Go a>b, c>d, e>f etc THEN b>c, d>e etc.  Reason
is that you may want to change the connections, and if it's early in the
daisy chain, you have to unwrap the whole lot.  Sometimes an unwrapped wire
can be re-wrapped, but it won't provide a RELIABLE connection.  This
matters, since a good wire-wrap connection is very good, certainly better
than single-sided PCB.  One guy here one time wrote a program to sort a
netlist to give this coherent two-level wrap.  When used with our
long-obsolete PCB layout program to get a good placement, meant that boards
were wrapped a lot faster than the 30 wraps/hour quoted in this list by
someone who once did it for a living.  I suspect reason is that most of the
time is taken identifying unambiguously the two pins to be wrapped, and/or
checking the work with a continuity tester - actually doing the stripping
and wrapping is a matter of seconds.

3.  If you're going to do any significant amount of wrapping (or for
sustained periods), I'd advise shelling out the megabucks for a powered
cut-strip-wrap tool.  The heads on these things cost over 200 UKpound, but
they make life very easy.  (The heads are easily damaged by inexperienced
users.)  Main problem with a powered tool is that it works by tension, so
the wrapped board has a tendency to come out of the assembly frame with a
pronounced curvature!  There are ways round this, which I won't bore you
with, especially as any engineer or technician can work out their own.

4.  Just because a design works on wire-wrap, doesn't mean it will work on
PCB!  Since wire-wrap is essentially point-to-point, and the connections are
often at almost random orientations (and certainly with no sharp corners
except at pins), the high-frequency characteristics are totally different to
those of a PCB.  A PCB may suffer much more crosstalk and interference, and
there may be signal skews that were absent on the wire wrap board.
Wire-wrapping is perfectly capable of functioning correctly for years, so
only change to PCB if quantity or other considerations such as space dictate.

5.  Surface mount and wire-wrap CAN go together.  It is most unfortunate
that Vero stopped making a wonderful system that allowed you to put together
what amounted to custom wire-wrap surface mount footprints for PLCC
packages.  However, there are still lots of companies out there making
megabucks selling transition connectors/sockets/adaptors.

6.  A previous comment said don't waste two colours just on Vcc and Gnd -
omitting to mention that most prototyping boards provide a Vcc/Gnd grid that
you link the sockets to with Z links (so called because they are more or
less that shape - you drop them over power pins and solder in place before
starting wrapping).  It's also a good idea to solder a decoupler between the
power pins at this stage - adding after wrapping is not easy, unless you
aren't bothered about getting the capacitor closely connected to the IC
pins, in which case why bother at all?  Z links should not be used to
connect pins such as chip selects and output enables to power - you may want
to change a permanent enable to controlled enable!

7.  It's easy to implement a "branching star" connection scheme in
wire-wrap, and this may be very useful for analogue signals and to minimise
clock skew.  Just watch out for the wrapping strategy as per comment 2
should there be any possibility you might want to modify the net.

8.  An undocumented wire-wrap, or worse, a documented wire-wrap that's been
modified in unrecorded ways, is an absolute nightmare to reverse-engineer
for the actual netlist.  It's the sort of mistake lots of people make - once.

That wraps up my 2p worth.  Sorry folks, couldn't resist.

Tim Forcer            Tel: (+44) (0)1703 593362
                     Fax: (+44) (0)1703 592053
                   email:  EraseMEtmf@spam@ecs.soton.ac.uk
Department of Electronics & Computer Science
Room 3005, Building 35
The University, Southampton, SO17 1BJ     UK

1997\06\12@094603 by myke predko

1997\06\12@195907 by Ross McKenzie

<big unwrap>

>That wraps up my 2p worth.  Sorry folks, couldn't resist.
>
>Tim Forcer            Tel: (+44) (0)1703 593362
>                      Fax: (+44) (0)1703 592053
>                    email:  @spam@tmfspam_OUT.....ecs.soton.ac.uk
>Department of Electronics & Computer Science
>Room 3005, Building 35
>The University, Southampton, SO17 1BJ     UK
>

Two comments from Down Under in addition to Tim Forcer's excellent summary
of the art.

1. There used to be available some thin plastic sheets which slid over the
wire wrap socket pins and provided clearly readable numbers for each wire
wrap pin from the action side. You could also write the circuit reference,
IC4, etc on these little cheat sheets. I would never attempt a wrap job of
any size without these sanity-savers. Nothing worse than putting your head
on the pillow at night and find that you are still counting 1..28 looking
through the bottom of the IC.

2. I always used a photocopy of the circuit being wrapped and drew along
each circuit track with a bright green felt tip pen as it was wrapped. There
was never any doubt about whether a connection had been done despite ringing
telephones, etc.

Regards,

Ross McKenzie
Melbourne Australia

'wire wrapping and SimmStick.'
1997\06\12@201749 by Don McKenzie

myke predko wrote:

big snips ---------

> Actually, for PICs, I should point out that the SIMMSticks are great
> prototyping tools (I used one for one of the projects in my book) and can
> reduce your prototype build drastically.  Mixing them with point to point
> and wire-wrapping can be a very effective PIC prototyping method.
> That wraps up my 2p worth.  Sorry folks, couldn't resist.
> Sorry Tim for the long missive on wire wrap versus other forms,
> myke

Glad someone finally got around to this point Myke. I too am a fan of
wire wrap and have used it for small and large prototypes, however
having all your PIC circuitry on a 30 pin SimmStick module means you
only have to wire wrap, or solder point to point your specific I/O.

And when you have finished your birdsnest, and finally have it
de-bugged, you then pull out your SimmStick and re-use it in your next
project.

New SimmSticks are now appearing that may even cover your specific I/O
task.

Interfacing to the SimmStick can be done via a set of 30 male/female
pins, or a 30 pin memory module socket. This lends itself readily to
breadboard, and veroboard interfacing.

SimmStick also has proto type boards, so for a one off design, the
SimmStick proto board becomes the final product. You only need to join
your CPU board to your Proto board with a simple bus using veroboard or
male/female pins. Suitable veroboard that has 30 tracks in parallel at
.1" centers must be one of the most common boards available off the
shelf.

Don McKenzie  spamBeGonedonEraseMEdontronics.com   http://www.dontronics.com

PICSTART and Newfound PIC Programmers Firmware Upgrades.
SLI, the serial LCD that auto detects baud rates from 100 to 125K bps.
SimmStick(tm) A PIC proto PCB the size of a 30 pin Simm Memory Module.
Send a blank message to infospamBeGonedontronics.com for more details.

1997\08\09@090627 by Octavio Nogueira

I have routines to work with DS1802 1 wire termometer, if you want
I can send it to you.

Regards,

Octavio
======================================================
Octavio Nogueira  - e-mail:   RemoveMEnogueira@spam@spamBeGonemandic.com.br
http://www.geocities.com/~oct_nogueira
"ProPic" Production PIC Programmer Windows under US$20
======================================================
----
De: Frank Schmalz <.....schmalz@spam@EraseMEBV.RZ.FH-MUENCHEN.DE>
Para: .....PICLISTRemoveMEMITVMA.MIT.EDU
Data: Sexta-feira, Agosto 08, 1997 09:32
Assunto: DS2430 1-Wire EEprom with pic ?

>Hi,
>has anyone worked with the Dallas DS2430 or other 1-Wire bus chips yet?
>I want to connect a DS2430 246 Bit EEprom to store the last setpoint of
my
>instrument to the PIC16C72. I have the data-sheet, but somehow I have a
>feeling that I will need a little bit more than that. Does anyone have
more
>information, knows where to get more information, or even could give me
>some hints ?

1997\08\09@103313 by Guy Farebrother

If possible could I please get a copy of these routines? I am looking at
talking to a DS1996 for memory storage and I think it uses the same
one-wire interface.

Thanks in advance

----------
{Quote hidden}

> From: Octavio Nogueira <.....nogueiraSTOPspam@spam@MANDIC.COM.BR>
> To: PICLISTEraseME@spam@MITVMA.MIT.EDU
> Subject: Re: DS2430 1-Wire EEprom with pic ?
> Date: Saturday, August 09, 1997 7:05 AM
>
> I have routines to work with DS1802 1 wire termometer, if you want
> I can send it to you.
>
> Regards,
>
> Octavio
> ======================================================
> Octavio Nogueira  - e-mail:   RemoveMEnogueiraspamBeGonemandic.com.br
> http://www.geocities.com/~oct_nogueira
> "ProPic" Production PIC Programmer Windows under US$20
> ======================================================
>  ----
> De: Frank Schmalz <spamBeGoneschmalzKILLspam@spam@BV.RZ.FH-MUENCHEN.DE>
> Para: PICLISTspam_OUT@spam@MITVMA.MIT.EDU
> Data: Sexta-feira, Agosto 08, 1997 09:32
> Assunto: DS2430 1-Wire EEprom with pic ?
>
> >Hi,
> >has anyone worked with the Dallas DS2430 or other 1-Wire bus chips yet?
> >I want to connect a DS2430 246 Bit EEprom to store the last setpoint of
> my
> >instrument to the PIC16C72. I have the data-sheet, but somehow I have a
> >feeling that I will need a little bit more than that. Does anyone have
> more
> >information, knows where to get more information, or even could give me
> >some hints ?

I'm working on a simple serial control project and need some ideas please.
My application requires that a master unit transmit and recieve from as
many as 30 slave units.
The messages are only a byte long and the master will pole all slaves. I
need a way of powering and communicating with the slaves via a 3 pin mic
lead.(sheilded twisted pair). I would also like to use the system on
exsisting audio lines thus leaving only one wire for comms.(and a ground).
The final problem is the comms need to be inaudible(out of the audio
range.) Natsemi have a powerline modem chip whick will operate on a carrier
up to 50 Khz however it needs the mains zero crossing for synchronising and
im running dc. Any Ideas Huh?!!

Cheers
Richard Bond..
spamBeGonerichardb@spam@mailbox.uq.edu.au

1997\10\15@120010 by Pierce Nichols

1997\10\15@213358 by Peter Wintulich

It looks like you could use a similar method to the radio stations. They send
broadcast quality audio over a two wire ballanced line, they have center tap
the transformers at each end. Then they use earth as one wire and the center
taps as the second wire.

You could use the same idea.
1) use the phantom power (about 48V) to power the Micros,
2) super impose the data on the power as a pulse per bit time.


I have a rough untested design that uses for the :-
Transmitter == A tristate o/p pin, dc isolation cap, two resistors as voltage
divider.

Reciver == An opamp, four resistors and a cap.
                and maybe a 555 ic

Phantom power is often taped off the ballanced line with a couple of resistors.


Regards
Peter Wintulich
RemoveMEPwintuliEraseMEKILLspamMicrobits.com.au

1997\10\16@003411 by Mike Keitz

On Thu, 16 Oct 1997 11:09:13 +0930 Peter Wintulich
<spamBeGonePWintulichspam_OUTRemoveMEMICROBITS.COM.AU> writes:
>It looks like you could use a similar method to the radio stations.
>They send
> broadcast quality audio over a two wire ballanced line, they have
>center tap
> the transformers at each end. Then they use earth as one wire and the
>center
> taps as the second wire.

The result is the audio signal is sent differentially between the two
wires in the pair, and the DC is sent common-mode.  Good transformers
(for minimum degradation of the audio signal, for recording-studio
quality) are likely to be expensive.  If you just need PA or broadcast
quality then this could work well.


>
>You could use the same idea.
>1) use the phantom power (about 48V) to power the Micros,

I don't know why 48V would be required, use about 12V and pass it through
7805 regulators to power the PIC.

>2) super impose the data on the power as a pulse per bit time.
>
>
>I have a rough untested design that uses for the :-
>Transmitter == A tristate o/p pin, dc isolation cap, two resistors as
>voltage
> divider.
>
Design the driver so if the line gets shorted (sudden change in voltage
will cause the coupling cap to discharge through the driver), reversed,
or overvolted, the PIC ouput is safe.  This probably means using an
external driver, not the PIC output directly.

At high frequences, the transformer may distort attempts to apply a
common-mode signal via the center tap.  If it were an ideal transformer
it wouldn't, but there will be some leakage in any real transformer.
Connecting small capacitors from the audio lines (ends of the winding) to
the center tap should solve this.

>Reciver == An opamp, four resistors and a cap.
>                 and maybe a 555 ic

Yes, just couple the power line signal from before the voltage regulator
into an amplifier and clean it up to logic levels.  The voltage regulator
may not like having a bunch of high-frequency junk at its input.  Use a
LC filter so the L is a choke to remove data from the power and the C
gives the regulator the large input capacitance that they like.  If the L
in the filter is one side of a transformer then it would be easy to use
the other side for data in-out using a differential line driver/receiver
chip.

The data channel won't have response to DC like a wired RS-232 connection
does.  For low bit rates, consider FSK modulation / demodulation using
4046 or similar chips.  This keeps the data signal frequency out of the
audio range.  At high bit rates (likely higher than a PIC with something
else to do can generate easily directly), use a Manchester code or
similar so there is no DC content.  The Manchester code will also limit
the low-frequency component of the data signal to about half the bit
rate.
>
>Phantom power is often taped off the ballanced line with a couple of
>resistors.

This could work for a low power device (like a PIC circuit).  Not using a
transformer means the transducer (microphone, etc) operates with the DC
and data still common-mode.

1997\10\16@015856 by Peter Wintulich

>>
>>You could use the same idea.
>>1) use the phantom power (about 48V) to power the Micros,
>
>I don't know why 48V would be required, use about 12V and pass it through
>7805 regulators to power the PIC.


The Phantom power I was referring to is sent from standard audio mixing desks
for  powering small amplifiers inside some mikes. Most desks have switches to
enable this option on a channel by channel basis.

The 48V is what the power supply for the mixing desk puts out for phantom power.
The actual line voltage is I expect much less. Also I do not know the polarity
of the 48V.

Regards

Peter Wintulich
.....PwintuliRemoveMEmicrobits.com












                            !

1997\10\16@024317 by Dwayne Reid

>The Phantom power I was referring to is sent from standard audio mixing desks
> for  powering small amplifiers inside some mikes. Most desks have switches to
> enable this option on a channel by channel basis.
>
>The 48V is what the power supply for the mixing desk puts out for phantom
power.
>The actual line voltage is I expect much less. Also I do not know the polarity
> of the 48V.

Most consoles use a pair of well matched 6.8K resistors from the +48V rail
to pins 2 & 3 of the input connector (pin 1 is gnd).  Some (older) consoles
using input transformers feed the +48V to the center tap of the input
transformer.  They usually include a 3.3K resistor for current limit, but I
have seen values ranging from 6.8K down to no series resistor at all.  Count
on modern consoles using the 2 closely matched 6.8K resistors.  The phantom
voltage polarity is positive to the signal pins, negative to gnd.

Dwayne Reid   <dwayner@spam@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, Alberta, CANADA
(403) 489-3199 voice     (403) 487-6397 fax

1997\10\16@034828 by ht

'two wire coms [OT]'
1997\10\16@165549 by Eric van Es

On this subject: did anyone else hear about the nice idea of using powerlines
to connect ppl to the 'net?

News just broke here...

Richard wrote:

{Quote hidden}

> I'm working on a simple serial control project and need some ideas please.
> My application requires that a master unit transmit and recieve from as
> many as 30 slave units.
> The messages are only a byte long and the master will pole all slaves. I
> need a way of powering and communicating with the slaves via a 3 pin mic
> lead.(sheilded twisted pair). I would also like to use the system on
> exsisting audio lines thus leaving only one wire for comms.(and a ground).
> The final problem is the comms need to be inaudible(out of the audio
> range.) Natsemi have a powerline modem chip whick will operate on a carrier
> up to 50 Khz however it needs the mains zero crossing for synchronising and
> im running dc. Any Ideas Huh?!!
>
> Cheers
> Richard Bond..
> EraseMErichardbRemoveMESTOPspammailbox.uq.edu.au

--
Eric van Es               | Cape Town, South Africa
RemoveMEvanesKILLspamTakeThisOuTilink.nis.za | http://www.nis.za/~vanes
LOOKING FOR TEMPORARY / HOLIDAY ACCOMODATION?
http://www.nis.za/~vanes/accom.htm

1997\10\17@001237 by Harold M Hallikainen

On Thu, 16 Oct 1997 22:50:42 +0200 Eric van Es <spamBeGonevanes@spam@ILINK.NIS.ZA>
writes:
>On this subject: did anyone else hear about the nice idea of using
>powerlines
>to connect ppl to the 'net?
>
>News just broke here...
>

       Doesn't sound like much to me.  Power lines are real noisey and
any communications RF on them stops at the local step-down transformer.
So, the low voltage power line could, I suppose, be used as a local drop,
and they could put a router on each pole with a transformer to put info
onto the higher voltage lines higher on the pole.  But, what is the data
capacity of those lines?  So...  I don't think there's much capability
here... but I've been wrong before.

Harold

1997\10\17@082323 by Mike Smith

-----Original Message-----
From: Eric van Es <RemoveMEvanesspam_OUTILINK.NIS.ZA>
To: PICLISTspamMITVMA.MIT.EDU <spam_OUTPICLISTspam_OUTspam_OUTMITVMA.MIT.EDU>
Date: Friday, 17 October 1997 6:34
Subject: Re: two wire coms [OT]


>On this subject: did anyone else hear about the nice idea of using
powerlines
>to connect ppl to the 'net?
>
>News just broke here...
>


What a great idea!  Hang on a second while I jack into
Cyberspace(tm)(c)......
Fumbles with clipleads on the end of IEC(also tm I guess) mains cable.......
Connects Neutral to wristwatch.... nothing so far.
Picks up Acti....
no carrie
#&D:\pic\pic archive 3Q@*

















MikeS
<mikesmith_ozspam_OUTrelaymail.net>

1997\10\17@084925 by Jack Warren

1997\10\17@115634 by Pekka Ritamaki

1997\10\17@133553 by Reginald Neale

>On Thu, 16 Oct 1997 22:50:42 +0200 Eric van Es <RemoveMEvanesKILLspam@spam@ILINK.NIS.ZA>
>writes:
>>On this subject: did anyone else hear about the nice idea of using
>>powerlines
>>to connect ppl to the 'net?
>>
>>News just broke here...
>>
>
>        Doesn't sound like much to me.  Power lines are real noisey and
>any communications RF on them stops at the local step-down transformer.
>So, the low voltage power line could, I suppose, be used as a local drop,
>and they could put a router on each pole with a transformer to put info
>onto the higher voltage lines higher on the pole.  But, what is the data
>capacity of those lines?  So...  I don't think there's much capability
>here... but I've been wrong before.
>
>Harold

Wireless to each distribution xfmr might work. Would require striking a
deal with the power company.

Reg

1997\10\17@142039 by Eric van Es

Dows the pole pig have a more explicit name?

Jack Warren wrote:

> > On this subject: did anyone else hear about the nice idea of using
powerlines
{Quote hidden}

> > to connect ppl to the 'net?
> >
> > News just broke here...
> >
>
> Interesting.  How do they get past the pole pig?
>
> Jack Warren

--
Eric van Es               | Cape Town, South Africa
vanesspamBeGone.....ilink.nis.za | http://www.nis.za/~vanes
LOOKING FOR TEMPORARY / HOLIDAY ACCOMODATION?
http://www.nis.za/~vanes/accom.htm

'DS1307 2 WIRE PROTOCOL'
1997\10\23@163326 by WF AUTOMA‚ÌO

Hi,

I have an IR receiver /repeater build that detect IR signal, and send it by wire to a photodiode.
Istead of using a photodiode I wont to send the code through 220V AC wire, and build some PIC based receivers, in order to respond to specific codes to turn on/off lights like systems using X10.

Dose anybody can help me on this, with a schema or so, to interface to 220V and send / receave a signal  ?

Many thanks,

Alberto Costa
Portugal
E:Mail: KILLspamalberto_costa.....edinfor.pt

1997\11\07@103623 by Alberto Costa

Hi,

I have an IR receiver /repeater build that detect IR signal, and send it by wire to a photodiode.
Istead of using a photodiode I wont to send the code through 220V AC wire, and build some PIC based receivers, in order to respond to specific codes to turn on/off lights like systems using X10.

Dose anybody can help me on this, with a schema or so, to interface to 220V and send / receave a signal  ?

Many thanks,

Alberto Costa
Portugal
E:Mail: spam_OUTalberto_costaKILLspamedinfor.pt

'[OT] 1394/FireWire'
1997\11\25@035417 by ht

I was wondering if anyone on the list has done anything on 1394/FireWire? I
have connected it to a PIC17C44, and have a few questions I would like to
discuss. Please contact me by e-mail, RemoveMEhtRemoveMEEraseMEneo.no

Thanks,
Haavard
------------------------------------------------
HŒvard T¿rring
KILLspamhtspamBeGoneneo.no    xplisitspamneo.no    RemoveMEsimplisitspamBeGoneRemoveMEneo.no
Norsk Elektro Optikk A/S       Tel: +47 67974700
PoBox 384                      Fax: +47 67974900
1471 SkŒrer.
Norway

1998\03\06@023853 by PeterAT&T

Hi,
Try http://www.dvp.com
It is cheaper and way better then linx.
Good luck,
Peter

-----Original Message-----
From: Herbert Graf <KILLspamhgrafspamBeGoneGEOCITIES.COM>
To: @spam@PICLISTSTOPspam@spam@MITVMA.MIT.EDU <PICLISTspamBeGonespamBeGoneMITVMA.MIT.EDU>
Date: Thursday, March 05, 1998 10:05 PM
Subject: [OT] Wireless RF Modules


>        I am interested in purchasing wireless RF modules which will
connect a PIC
>with display to a PC eventually. If one doesn't know what I am talking
>about, the type of item I am interested in is offered by LINX technologies
>(http://www.linxtechnologies.com/). I would like to buy their units, but
>they are quite far away and after conversion to Canadian dollars it becomes
>quite expensive, $70 for one pair. So, I am looking for the same kind of
>product, about 250m range, capable of digital and/or analog transmissions,
>but cheaper and preferably closer to the Canadian border. If anybody has
>ever dealt with other companies that offer similar products I would love to
>hear from them. Thank you in advance for any info. TTYL

1998\03\06@125022 by John A. Craft

1998\03\06@125047 by Craig Webb

1998\03\06@131724 by Craig Lee

Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US and
the receiver is about $7US.
They are in the 900 MHz range.  However, you'll have to add a handful of
external components if you don't
buy their full system. Coils, caps, transistors, antenna, etc.  I think the
baud rate can go to about 10K.

They do have a development kit with two transceiver boards, at89C251
microcontrollers,
and some level shifting to the PC serial port.  I think the kit is about
$200US.

Give them a look see.

I need a bit more range than the DOC will allow without a license.  So I'm
trying to find some spread spectrum
modules that are reasonably priced.  The best price I can find so far is
about $750 each!

Later,

Craig

----------
> From: Herbert Graf <spamBeGonehgrafGEOCITIES.COM>
> To: spam_OUTPICLISTSTOPspamMITVMA.MIT.EDU
> Subject: [OT] Wireless RF Modules
> Date: Thursday, March 05, 1998 3:04 PM
>
>
>         I am interested in purchasing wireless RF modules which will
connect a PIC
> with display to a PC eventually. If one doesn't know what I am talking
> about, the type of item I am interested in is offered by LINX
technologies
> (http://www.linxtechnologies.com/). I would like to buy their units, but
> they are quite far away and after conversion to Canadian dollars it
becomes
> quite expensive, $70 for one pair. So, I am looking for the same kind of
> product, about 250m range, capable of digital and/or analog
transmissions,
> but cheaper and preferably closer to the Canadian border. If anybody has
> ever dealt with other companies that offer similar products I would love
to
> hear from them. Thank you in advance for any info. TTYL

1998\03\06@135050 by DREITEK

1998\03\06@142610 by Craig Lee

Interesting, because I have the Virtual Wire kit, and the processor is
the AT89C2051 from Atmel.

Did they change chips?


Craig

----------
{Quote hidden}

> From: John A. Craft <RemoveMEcraftspamNCS-SSC.COM>
> To: TakeThisOuTPICLISTspamRemoveMEMITVMA.MIT.EDU
> Subject: Re: [OT] Wireless RF Modules
> Date: Friday, March 06, 1998 8:16 AM
>
>
> Try the Virtual Wire from RF Monolithics
>
>
> http://www.rfm.com
>
> It uses a '84 to packetize the data.
>
> jc.
>
> >        I am interested in purchasing wireless RF modules which will
> connect a PIC
> >with display to a PC eventually. If one doesn't know what I am talking
> >about, the type of item I am interested in is offered by LINX

technologies
> >(http://www.linxtechnologies.com/). I would like to buy their units, but
> >they are quite far away and after conversion to Canadian dollars it
becomes
> >quite expensive, $70 for one pair. So, I am looking for the same kind of
> >product, about 250m range, capable of digital and/or analog
transmissions,
> >but cheaper and preferably closer to the Canadian border. If anybody has
> >ever dealt with other companies that offer similar products I would love
to
> >hear from them. Thank you in advance for any info. TTYL
> >

1998\03\06@151003 by ndie Ohtsji [4555]

Hi Craig,

Do you know what the range of the 900MHz devices can deliver.
I have a similar application which I wish to transmit at a distance of
about 800 meters (1/2 mile).

What is the DOC (now Industry Canada) and FCC limit without a license
in the 900MHz band?

Was also hoping to use the Linx HP series Tx & Rx modules.

-Randie (Also stuck in Canada and hoping to find a cheaper source
of Tx/Rx modules)

KILLspamrohtsjispamspam_OUTglenayre.com


> From craigleeRemoveMEAGT.NET Fri Mar  6 10:22:08 1998
>
> Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US and
> the receiver is about $7US.
> They are in the 900 MHz range.  However, you'll have to add a handful of
> external components if you don't

> I need a bit more range than the DOC will allow without a license.  So I'm

1998\03\06@180445 by Ryan E. Stafford

1998\03\06@185408 by Craig Lee

> Do you know what the range of the 900MHz devices can deliver.
> I have a similar application which I wish to transmit at a distance of
> about 800 meters (1/2 mile).

It's 902-928 Mhz.

>
> What is the DOC (now Industry Canada) and FCC limit without a license
> in the 900MHz band?

Because spread spectrum is frequency hopping, and it doesn't 'JAM' anything
due to it's transmission methodology, there is no license requirement. I
think
FCC part 47 mentions this.


{Quote hidden}

> Was also hoping to use the Linx HP series Tx & Rx modules.
>
> -Randie (Also stuck in Canada and hoping to find a cheaper source
> of Tx/Rx modules)
>
> EraseMErohtsjiSTOPspamRemoveMEglenayre.com
>
>
> > From spam_OUTcraigleeRemoveMEEraseMEAGT.NET Fri Mar  6 10:22:08 1998
> >
> > Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US

and
> > the receiver is about $7US.
> > They are in the 900 MHz range.  However, you'll have to add a handful
of
> > external components if you don't
>
> > I need a bit more range than the DOC will allow without a license.  So
I'm

1998\03\06@220716 by Tom Mariner

1998\03\06@220731 by Tom Mariner

The frequency bands 902-928, 2.45GHz and 5.8 GHz, when used with certain
restrictions in two methods of spread spectrum modulation can have a
theoretical maximum of 1W US. The 2.4 and 5.8 GHz bands generally overlap
in Europe where the limit is half that and in Japan where the limit is
generally 100 mw. In addition, there are more restrictions on antenna gain
in Europe / Japan than in the US.

Tom

On Friday, March 06, 1998 4:13 PM, Ryan E. Stafford
[SMTP:TakeThisOuTryanRemoveME@spam@BROWNINTL.COM] wrote:
> I believe the unliciensed 900MHz band is restricted to 30mW xmitter
output
> in the USA.  The actual frequency is also important, i.e. 915MHz.  With a
> 3db antenna and line-of-sight you should be good for 1 mile.  Remember
> antenna placement, to escape ground effects it needs to be about 35 feet
up.
> Each country has differing requirements.  The 2.4GHz band seems to be the
> most liberial worldwide.  Search for "FCC" and I'm sure you will find
more
> than you really wanted to know.
>
> Have a nice day! :)
> Ryan
>
>
***************************************************************************
> I do not feel obliged to believe that the same God who has endowed us
with
> sense, reason, and intellect has intended us to forgo their use. -
Galileo
>
***************************************************************************

1998\03\06@221548 by Sean Breheny

At 03:13 PM 3/6/98 -0600, you wrote:
>I believe the unliciensed 900MHz band is restricted to 30mW xmitter output
>in the USA.  The actual frequency is also important, i.e. 915MHz.  With a
>3db antenna and line-of-sight you should be good for 1 mile.  Remember
>antenna placement, to escape ground effects it needs to be about 35 feet up.

<SNIP>

35 feet??! I'm not an expert on RF, but I do seem to remember that the
general rule of thumb for antennas is that the separation between them and
the ground should be some multiple of their wavelength, and for the 146 MHz
band, 6 feet is usually considered enough(if I remember correctly), so I
would hardly think that the minimum distance for 900MHz would be greater! I
could be wrong, just curious as to where 35 feet came from.

Sean

+--------------------------------+
| Sean Breheny                   |
| Amateur Radio Callsign: KA3YXM |
| Electrical Engineering Student |
+--------------------------------+
Fight injustice, please look at
http://homepages.enterprise.net/toolan/joanandrews/

Personal page: http://www.people.cornell.edu/pages/shb7
EraseMEshb7RemoveMEcornell.edu
Phone(USA): (607) 253-0315

1998\03\07@110414 by Craig Webb

These modules aren't cheap ($1250 US each!), but if you want 20 miles (!),
try Freewave technologies. They run up to 115 kbps spread spectrum, and are
all set up for RS232.

http://www.freewave.com

Craig Webb

At 10:50 AM 3/6/98 -0800, you wrote:
{Quote hidden}

>Hi Craig,
>
>Do you know what the range of the 900MHz devices can deliver.
>I have a similar application which I wish to transmit at a distance of
>about 800 meters (1/2 mile).
>
>What is the DOC (now Industry Canada) and FCC limit without a license
>in the 900MHz band?
>
>Was also hoping to use the Linx HP series Tx & Rx modules.
>
>-Randie (Also stuck in Canada and hoping to find a cheaper source
>of Tx/Rx modules)
>
>spamrohtsji.....spamglenayre.com
>
>
>> From craigleespam_OUT@spam@AGT.NET Fri Mar  6 10:22:08 1998
>>
>> Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US and
>> the receiver is about $7US.
>> They are in the 900 MHz range.  However, you'll have to add a handful of
>> external components if you don't
>
>> I need a bit more range than the DOC will allow without a license.  So I'm
>
>

1998\03\07@135833 by Ranna M. V.

Dear Criag,
At 08:41 AM 3/6/98 -0700, you wrote:
>Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US and
>the receiver is about $7US.
(sbip)

I am interseted in using them, Is this price in single piece units?

Thank you,
Ranna M. V.
Consultant Engineer

NEURON SYSTEMS
4/77, 13th Main Road,                        Tel/Fax:+91-80-529 6071
HAL 2nd Stage, Bangalore 560 008             E.Mail: .....rannaspam.....pobox.com
INDIA

1998\03\07@161842 by Craig Lee

Well the antenna is made in such a way that the groundplane is simulated
6 feet below the tip of the antenna.

----------
> From: Sean Breheny <shb7KILLspamEraseMECORNELL.EDU>
> To: EraseMEPICLIST@spam@@spam@MITVMA.MIT.EDU
> Subject: Re: [OT] Wireless RF Modules
> Date: Friday, March 06, 1998 8:14 PM
>
>
> At 03:13 PM 3/6/98 -0600, you wrote:
> >I believe the unliciensed 900MHz band is restricted to 30mW xmitter
output
> >in the USA.  The actual frequency is also important, i.e. 915MHz.  With
a
> >3db antenna and line-of-sight you should be good for 1 mile.  Remember
> >antenna placement, to escape ground effects it needs to be about 35 feet
up.
>
> <SNIP>
>
> 35 feet??! I'm not an expert on RF, but I do seem to remember that the
> general rule of thumb for antennas is that the separation between them
and
> the ground should be some multiple of their wavelength, and for the 146
MHz
{Quote hidden}

> band, 6 feet is usually considered enough(if I remember correctly), so I
> would hardly think that the minimum distance for 900MHz would be greater!
I
> could be wrong, just curious as to where 35 feet came from.
>
> Sean
>
> +--------------------------------+
> | Sean Breheny                   |
> | Amateur Radio Callsign: KA3YXM |
> | Electrical Engineering Student |
> +--------------------------------+
> Fight injustice, please look at
> http://homepages.enterprise.net/toolan/joanandrews/
>
> Personal page: http://www.people.cornell.edu/pages/shb7
> @spam@shb7spamKILLspamcornell.edu
> Phone(USA): (607) 253-0315

1998\03\07@161845 by Craig Lee

I think their price list is on the web site.

I believe the prices are based on production quantities, but you can
definetly get some samples.

Just check out their website.

Craig

----------
> From: Ranna M. V. <spamBeGonerannaRemoveMEEraseMEBLR.VSNL.NET.IN>
> To: RemoveMEPICLISTKILLspamRemoveMEMITVMA.MIT.EDU
> Subject: Re: [OT] Wireless RF Modules
> Date: Friday, March 06, 1998 3:19 PM
>
>
> Dear Criag,
> At 08:41 AM 3/6/98 -0700, you wrote:
> >Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US
and
{Quote hidden}

> >the receiver is about $7US.
> (sbip)
>
> I am interseted in using them, Is this price in single piece units?
>
> Thank you,
>  Ranna M. V.
>  Consultant Engineer
>
>  NEURON SYSTEMS
>  4/77, 13th Main Road,                        Tel/Fax:+91-80-529 6071
>  HAL 2nd Stage, Bangalore 560 008             E.Mail: TakeThisOuTrannapobox.com
>  INDIA

1998\03\08@043004 by mats

Craig Lee wrote:
{Quote hidden}

>
> I think their price list is on the web site.
>
> I believe the prices are based on production quantities, but you can
> definetly get some samples.
>
> Just check out their website.
>
> Craig
>
> ----------
> > From: Ranna M. V. <spamBeGonerannaKILLspamTakeThisOuTBLR.VSNL.NET.IN>
> > To: EraseMEPICLIST.....KILLspamMITVMA.MIT.EDU
> > Subject: Re: [OT] Wireless RF Modules
> > Date: Friday, March 06, 1998 3:19 PM
> >
> >
> > Dear Criag,
> > At 08:41 AM 3/6/98 -0700, you wrote:
> > >Try RF Monolithics.  http://www.rfm.com Their transmitter is about $5US
> and
> > >the receiver is about $7US.
> > (sbip)
> >
> > I am interseted in using them, Is this price in single piece units?
> >
> > Thank you,
> >  Ranna M. V.
> >  Consultant Engineer
> >
> >  NEURON SYSTEMS
> >  4/77, 13th Main Road,                        Tel/Fax:+91-80-529 6071
> >  HAL 2nd Stage, Bangalore 560 008             E.Mail: spamrannapobox.com
> >  INDIA

this discussion hass deteriorated into discussions that have very little
substans.can anybody present a solution that makes a fast rf link
between to networkcards or a wireless modem.get real.instead of talking
about antenna spacing from ground.everyone with knowledge about rf
knows that trial and error togetherwith some knowledge is what yealds.

1998\03\08@154604 by Craig Lee

I phhart in your general direction. (Monty Python - The Holy Grail)

I'm sorry folks, I just couldn't help myself (;>

Craig

----------
> From: s-33963 <matsSTOPspamSOBER.PP.SE>
> To: PICLISTSTOPspamKILLspamMITVMA.MIT.EDU
> Subject: Re: [OT] Wireless RF Modules
> Date: Sunday, March 08, 1998 2:28 AM
> this discussion hass deteriorated into discussions that have very little
> substans.can anybody present a solution that makes a fast rf link
> between to networkcards or a wireless modem.get real.instead of talking
> about antenna spacing from ground.everyone with knowledge about rf
> knows that trial and error togetherwith some knowledge is what yealds.

1998\03\09@123640 by SHAWN ELLIS

'[OT] Wire capacity?'
1998\03\09@133339 by Brian Scearce

'[OT] Wireless RF Modules'
1998\03\09@133342 by Dan Larson

My $.02....

I have lately been attracted to mailing lists because of the lack of
flame wars, SPAM, and other bandwidth wasters.  This is in sharp contrast
the the worsening condition of the Usenet groups.

IMHO off-topic threads are fine once in a while.  They *can* be informative
and serve the general interests of all.  Keep in mind the clause "in the
general interests of all".  It is a key qualifier.  A good laugh now and then,
or a side discussion of RF, IR, etc don't bother me at all.  In fact, such
threads
give the list more life and more depth. Keep in mind also that it would be very
difficult to keep up with all of the many different topics if each was in
a separate list. If the list were strictly and completely on topic at all times,
it would also be dull and flat.  When things degrade into a flame war the
mailing
list becomes no better than the aforementioned Usenet.

So far I have enjoyed this list immensely, and hope that I can continue to do
so!
The general intelligence level of this far exceeds any where else on the 'net.
No body who has posted to this list since I have subscribed has yet earned a
place in my "trash filter".

Dan

On Mon, 9 Mar 1998 11:27:14 EST5EDT, SHAWN ELLIS wrote:

{Quote hidden}

>> Craig Lee wrote:
>> this discussion hass deteriorated into discussions that have very little
>> substans.can anybody present a solution that makes a fast rf link
>> between to networkcards or a wireless modem.get real.instead of talking
>> about antenna spacing from ground.everyone with knowledge about rf
>> knows that trial and error togetherwith some knowledge is what yealds.
>>
>Wow, your obviously a brain-child judgeing by your typing/spelling
>skills.  Mabye we should all bow down and ask your forgiveness for
>wasting your time/screen space.
>
>I, for one, don't know much about RF and I enjoyed that thread.  If
>you don't like it, just delete the message and keep your
>poorly-composed, naysaying replies off MY screen!
>
>No offense intended, of course....
>

*******************************
* Dan Larson                  *
* Software Engineer           *
* Micro Control Company       *
* email: @spam@dlarson.....spamcitilink.com *
*******************************

1998\03\09@133345 by mats

'[OT] Wire capacity?'
1998\03\09@152043 by Bob Fehrenbach

Brian Scearce <spambls..........BEST.COM> wrote:
>I'm wiring up a small project, and I'm not sure what gauge of wire
>to use.

Brian,

Transformer people use rules of thumb like 500 circular mils/amp.  This
takes into account the fact that the inside of a transformer will get
warmer than a wire in open air.

I think a reasonable estimate for your purposes would be something like
200 cir mils/amp.

For example, 30 gauge wire has a diameter of 10 mils giving an area
of 100 circular mils.  The above rule says you should be able to pass
half an amp and not melt the wire.

Another quick rule of thumb:  Subtracting 6 from the wire gauge
doubles the diameter, increasing the current capacity by 4.

AWG #24 has a diameter of 20 mils and should handle 2 amps.

In most cases it is not melting the wire that is the concern but the
voltage drop.  I would be more inclined to size the wire using that
as the main consideration.

--
Bob Fehrenbach    Wauwatosa, WI     bfehrenb.....execpc.com

1998\03\09@160006 by William Chops Westfield

1998\03\09@180339 by mjb

William Chops Westfield writes:
> It takes MUCH more current than 500mA to melt a piece of 30g wire-wrap wire.
> I just used my bencchtop supply to run 3A through a piece and it didn't even
> glow or discolor due to heating.
>
> That doesn't mean the rule of thumb is invalid, though.  I'd expect the
> first concern to be "excessive heating", just due to system issues. (and
> there's a LOT of wire in a transformer, so even a little bit of heat/cm will
> amount up.  Secondly, you'd run into "don't melt the insulation", followed
> by "don't melt the solder", with actual wire-melting WAY up there on the
> list of concerns.

According the the book "Reference Data for Engineers; Radio, Electronics,
Computer, and Communications, 7th ed." ISBN 0-672-21563-2 (A copy should
be on every electrical engineer's desk), the fusing current for 30 ga
copper wire is 10.2A (that is, the current at which the wire will melt).
the formula is as given I=K*d^(3/2), where d is the diameter in inches and
K is a constant that depends on the metal, aluminum K=7585, copper K=10244,
and so on.

The most important thing to be converned about is the wire (and junction)
resistance. a piece of another chart for annealed copper follows:
gauge       ohms/1000ft at 20C
12          1.588
14          2.525
18          6.385
26          40.81
30          103.2

So for power supplies, you can use ohms's law to figure out the voltage drop,
but for CMOS, it is very easy to get in trouble, because CMOS can cause
extremely high current spikes, which is why decoupling capacitors are
obligatory.  So the short answer is: for currents that pics can draw, 30ga
wire is fine.  If you need a big slug of current delivered in a short time,
start looking to heavier wires.

Why do I qualify the above paragraph for power supplies?  Remember, a wire
is not just a wire.  It is also an inductor and part of a capacitor, so
you must be aware of that on any line you are doing switching (i.e. introducing
high frequency components.

Matt








-----------------------------
Matt Bennett                |
KILLspammjbspam_OUThazmat.com              |
http://www.hazmat.com/~mjb/ |

1998\03\10@114515 by Bob Fehrenbach

  From my original post:
>    For example, 30 gauge wire has a diameter of 10 mils giving an area
>    of 100 circular mils.  The above rule says you should be able to pass
>    half an amp and not melt the wire.

  Note feeble and inadequate attempt at irony.  The original poster
  wanted to know if he could pass 20 ma through 30 ga wires.

William Chops Westfield <spam_OUTbillwTakeThisOuTCISCO.COM> wrote:

>It takes MUCH more current than 500mA to melt a piece of 30g wire-wrap wire.

  Agreed.  The 200 cir mils/amp guideline was not an attempt to
  estimate a catastrophic level but rather a quick way to determine
  a reasonably safe wire size.  In most cases, particularly prototypes etc,
  100 cir mils/amp will do fine.

  When you ran 3 amps through 30 ga wire (33 cir mils/amp)
  did you melt the insulation?    While testing wire wrap prototypes
  without my glasses on (a clip lead on the wrong pin) I have had
  wires glow for a while before they melted.  I think the power supply
  swung up over 5 amps.

--
Bob Fehrenbach    Wauwatosa, WI     .....bfehrenb.....RemoveMEexecpc.com

1998\03\10@150853 by Eric Smith

Bob Fehrenbach <spam_OUTbfehrenbTakeThisOuTEraseMEEXECPC.COM> wrote:
>    When you ran 3 amps through 30 ga wire (33 cir mils/amp)
>    did you melt the insulation?    While testing wire wrap prototypes
>    without my glasses on (a clip lead on the wrong pin) I have had
>    wires glow for a while before they melted.  I think the power supply
>    swung up over 5 amps.

[Note: these comments aren't particularly directed to Bob.]

This is why bench supplies have adjustable current limiting.  You should
set the current limit to just above the expected power consumption, and
keep an eye on the meter or the CC (constant current) mode light.

For example, if you only expect the circuit to draw 500 mA, don't set the
current limit to 3 A.

I can't believe how many people try to debug prototypes using PC power
supplies and other such junk.  The usual explanation given is "but they're
so cheap".  Which only proves my point.  How many chips (and whole
prototypes) can you afford to damage rather than buying a decent bench
supply?

Every time that CC comes on, the supply has possibly prevented damage.
I've lost count of how many times it's worked for me, but I know that I'd
have blown up a few expensive boards if I didn't have it.

Cheers,
Eric

1998\03\10@163835 by William Chops Westfield

'One-wire routines of the CCS C compiler'
1998\03\16@065011 by wterreb

1998\03\16@072829 by wterreb

{Quote hidden}

> Date:          Mon, 16 Mar 1998 08:52:15 -0800
> From:          WF AUTOMACAO <EraseMEwfspamBeGoneKILLspamambiente.com.br>
> Organization:  WF AUTOMACAO
> To:            RemoveMEwterrebspamBeGonespamplessey.co.za
> Subject:       Re: One-wire routines of the CCS C compiler

> Werner Terreblanche wrote:
> >
> > Hi
> >
> > Anybody out there using the CCS one-wire routines?   I tried
> > unsuccesfully this weekend to use the example routines that came
> > with the compiler to interface to the Dallas DS1820 one-wire digital
> > thermometer and I was wondering if anybody else have had success
> > doing this?
> >
> > Rgds
> > Werner
>
> Did you contact CCS?

Not yet.   I was rather hoping to find some other user of the
compiler here on the Piclist who has used these routines before.  It
does not seem a big enough deal to bother CCS with something which
is most probably a programming fault on my side.   Mind you, reading
my own message again, it looks as if I was trying to say that the CCS
routines are not working.  This is actually not what I meant....
What I meant to say was that I was unsuccessfull in implementing
their routines in trying to use it in my own application to
interface to a DS1820.    It does not mean that their routines are
incorrect and I feel that it is only fair that I correct myself
here. I'm actually very happy with the CCS compiler and have used it
successfully in a number of projects.
--
Werner Terreblanche     users.iafrica.com/w/we/wernerte/index.htm
@spam@wterrebspamplessey.co.za (work)  OR  TakeThisOuTwernerteKILLspam@spam@iafrica.com  (home)
Plessey SA, PO Box 30451,Tokai 7966, Cape Town, South Africa
or at home : Suite 251, PostNet X5061, Stellenbosch, 7599
Tel +27 21 7102251  Fax +27 21 7102886  Home +27 21 8523249
------------------------------------------------------------

1998\03\17@034921 by wterreb

1998\03\17@170512 by John Sanderson

Hi Everyone,

I'm using for PIC and BS2 and looking for a sample circuit and code to explain h
ow to use Dallas 1-wire communication interface.

I appreciate any help ...

Thanks

.....albertgoodwillRemoveMEgeocities.com

1998\08\08@112919 by Michael Hagberg

1998\08\08@121941 by Ake Hedman

1998\08\10@014959 by Philippe

At 06:40 08/08/98 -0700, you wrote:
>I'm using for PIC and BS2 and looking for a sample circuit and code to
explain >how to use Dallas 1-wire communication interface.

You will find:
       - code examples for 16C84,
       - UMPS project file with DS1820
       - a full simulation with 1-Wire protocol device DS1820 or DS1990,

with UMPS project examples:
       http://www.sistudio.com/umps

Regards,
       Philippe.

 +--------------------------------------------------------+
 |  Virtual Micro Design                                  |
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 |                                                        |
 |  Phone: ++33 559.438.458   Fax: ++33 559.438.401       |
 |                                                        |
 | E-Mail: KILLspamp.techerTakeThisOuTidls.izarbel.tm.fr                    |
 | URL:    http://www.sistudio.com/umps                   |
 +--------------------------------------------------------+

'Body worn transmittor/wireless/alarm if wearer fal'
1998\08\14@163815 by White Horse Design

Can anyone help with this (UK based) ??

At 20:57 14/08/98 +0100, you wrote:
{Quote hidden}

>Hello Adrian,
>
>Not sure whether you can help me as this is not exactly your line
>(but you might know 'a man who can').
>
>I'm looking for a small body worn transmittor which will send a signal
>to a receiver which will sound/flash an alarm if the wearer falls over.
>
>The person in need is a young lady with Learning Disabilities and
>epilepsy - so the Lifeline style phones won't help as she may well not
>be able to press the pendant/clip on button.
>
>She lives with her parents on a small holding and likes to go see the
>animals - parents don't like having to keep tabs as it doesn't give her
>any independance.
>
>I'm sure such things exist but can't find any references as most people
>are on the phone systems.
>
>Sorry to trouble you, but I thought you may be able to point me in the
>right direction.

You need to contact the BCS (British Computer Society) Disability group. An
ex-colleague of mine, Ruben Ashkenazy designed an LCD based cpu system with
a buzzer to remind patients to take their medication.

I'll look out their number and contact details.

Regards

Adrian
---
WWW    WWW   Adrian Gothard
WWW WW WWW   White Horse Design
WWWWWWWWWW   +44-385-970009 (Mobile/SMS), +44-118-962-8913/4 (voice/fax)
WWWW  WWWW   TakeThisOuTwhdspam_OUTzetnet.co.uk, http://www.users.zetnet.co.uk/whd
---
Developers of GPS satellite-based tracking systems for vehicles/helicopters

'Body worn transmitter/wireless/alarm if wearer fal'
1998\08\14@171316 by Montaigne, Mike

Would those imported $20. wireless doorbells work?
The main problem is false triggering.  Maybe others here can
give some suggestions - my first thought is a mercury switch
that feeds some simple logic (555/PIC?)  Set the switch so it
is made when vertical or upside down.  If the switch is made for a long
time,
the person is in trouble.  If the switch is making intermittently, the
person is walking,
moving etc. and that's OK.  The transmitter is small enough - could be
clipped to
a belt.  I have wired the receivers to a relay for other projects - finding
a logic level
signal in the receiver is fairly easy with a scope.  You could use this
signal
if the alarm was not loud enough or you wanted to trigger a phone
dialer, louder alarm, ect.  Another company called Linear makes longer
range transmitters/receivers - used for wireless security for example.
Mike

{Quote hidden}

> ----------
> From:         White Horse Design[SMTP:RemoveMEwhdspamSTOPspamZETNET.CO.UK]
> Sent:         Friday, August 14, 1998 4:35 PM
> To:   .....PICLISTEraseMEMITVMA.MIT.EDU
> Subject:      Body worn transmittor/wireless/alarm if wearer falls over
> project
>
> Can anyone help with this (UK based) ??
>
> At 20:57 14/08/98 +0100, you wrote:
> >Hello Adrian,
> >
> >Not sure whether you can help me as this is not exactly your line
> >(but you might know 'a man who can').
> >
> >I'm looking for a small body worn transmittor which will send a signal
> >to a receiver which will sound/flash an alarm if the wearer falls over.
> >
> >The person in need is a young lady with Learning Disabilities and
> >epilepsy - so the Lifeline style phones won't help as she may well not
> >be able to press the pendant/clip on button.
> >
> >She lives with her parents on a small holding and likes to go see the
> >animals - parents don't like having to keep tabs as it doesn't give her
> >any independance.
> >
> >I'm sure such things exist but can't find any references as most people
> >are on the phone systems.
> >
> >Sorry to trouble you, but I thought you may be able to point me in the
> >right direction.
>
> You need to contact the BCS (British Computer Society) Disability group.
> An
> ex-colleague of mine, Ruben Ashkenazy designed an LCD based cpu system
> with
> a buzzer to remind patients to take their medication.
>
> I'll look out their number and contact details.
>
> Regards
>
> Adrian
> ---
> WWW    WWW   Adrian Gothard
> WWW WW WWW   White Horse Design
> WWWWWWWWWW   +44-385-970009 (Mobile/SMS), +44-118-962-8913/4 (voice/fax)
> WWWW  WWWW   spamBeGonewhdRemoveMEzetnet.co.uk, http://www.users.zetnet.co.uk/whd
> ---
> Developers of GPS satellite-based tracking systems for
> vehicles/helicopters
>

'Body worn transmittor/wireless/alarm if wearer fal'
1998\08\14@223102 by Peter Grey

At 09:35 PM 14/08/98 +0100, you wrote:

Adrian,

I have such a system which is used in industry and operates at 77MHz. I do
not believe this is suitable for your area. However, I am currently
developing the same product to run at 916MHz and 433MHz. It will also be a
lot cheaper than the industrial system where a lot of different features are
required. It basically is a person down alarm with duress switch. It is
received at a base station or receiver and an alarm is sounded if the person
goes down or the duress switch is pressed. If more than one person is to be
monitored and over a greater area than about 100 metres radius then it will
need a processor based base station.

If you need further details email me privately.



All the best,



Peter Grey
Neosystems Australia


{Quote hidden}

>Can anyone help with this (UK based) ??
>
>At 20:57 14/08/98 +0100, you wrote:
>>Hello Adrian,
>>
>>Not sure whether you can help me as this is not exactly your line
>>(but you might know 'a man who can').
>>
>>I'm looking for a small body worn transmittor which will send a signal
>>to a receiver which will sound/flash an alarm if the wearer falls over.
>>
>>The person in need is a young lady with Learning Disabilities and
>>epilepsy - so the Lifeline style phones won't help as she may well not
>>be able to press the pendant/clip on button.
>>
>>She lives with her parents on a small holding and likes to go see the
>>animals - parents don't like having to keep tabs as it doesn't give her
>>any independance.
>>
>>I'm sure such things exist but can't find any references as most people
>>are on the phone systems.
>>
>>Sorry to trouble you, but I thought you may be able to point me in the
>>right direction.
>
>You need to contact the BCS (British Computer Society) Disability group. An
>ex-colleague of mine, Ruben Ashkenazy designed an LCD based cpu system with
>a buzzer to remind patients to take their medication.
>
>I'll look out their number and contact details.
>
>Regards
>
>Adrian
>---
>WWW    WWW   Adrian Gothard
>WWW WW WWW   White Horse Design
>WWWWWWWWWW   +44-385-970009 (Mobile/SMS), +44-118-962-8913/4 (voice/fax)
>WWWW  WWWW   .....whdEraseMEzetnet.co.uk, http://www.users.zetnet.co.uk/whd
>---
>Developers of GPS satellite-based tracking systems for vehicles/helicopters
>
>

'1-wire on PIC'
1998\08\18@112129 by Ake Hedman

'[STAMPS] DALLAS 1-wire interface with PIC and/or B'
1998\08\18@121742 by Auron, Chris J

Try:
http://bobo.shirenet.com/~dgc/stamp/d1820.htm


Chris

-----Original Message-----
From: "spamAlbertGoodwillspam_OUT@spam@geocities.com" [SMTP:spamAlbertGoodwill@spam@STOPspamgeocities.com]

Sent: Saturday, August 08, 1998 6:40 AM
To: "spamBeGonePICLISTspamBeGone@spam@MITVMA.MIT.EDU" [SMTP:RemoveMEPICLISTRemoveMERemoveMEMITVMA.MIT.EDU];
"picsKILLspamspamparallaxinc.com" [SMTP:spam_OUTpics@spam@parallaxinc.com];
"TakeThisOuTstampsspam_OUTparallaxinc.com" [SMTP:KILLspamstamps.....TakeThisOuTparallaxinc.com]
Subject: [STAMPS] DALLAS 1-wire interface with PIC and/or BS2


Hi Everyone,

I'm using for PIC and BS2 and looking for a sample circuit and code to
explain
how to use Dallas 1-wire communication interface.

I appreciate any help ...

Thanks

TakeThisOuTalbertgoodwillEraseMERemoveMEgeocities.com



- To subscribe -or- unsubscribe send e-mail to spam_OUTmajordomoRemoveME.....parallaxinc.com and
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'RS-232 <-> 1-Wire i/f'
1998\08\18@125311 by Ake Hedman

'RS-232 <-> 1-Wire i/f and SmartTemp routines'
1998\08\18@164820 by Ake Hedman

1998\08\24@102834 by Ake Hedman, Eurosource

'Body worn transmittor/wireless/alarm if wearer fal'
1998\08\24@191704 by Mark Hellman

We can help, this ties in nicely with one of our current projects. Please
send private mail to:  spammarkKILLspamKILLspamnavmasters.com

Have a GREAT day,

Mark

At 09:35 PM 8/14/98 +0100, you wrote:
{Quote hidden}

>Can anyone help with this (UK based) ??
>
>At 20:57 14/08/98 +0100, you wrote:
>>Hello Adrian,
>>
>>Not sure whether you can help me as this is not exactly your line
>>(but you might know 'a man who can').
>>
>>I'm looking for a small body worn transmittor which will send a signal
>>to a receiver which will sound/flash an alarm if the wearer falls over.
>>
>>The person in need is a young lady with Learning Disabilities and
>>epilepsy - so the Lifeline style phones won't help as she may well not
>>be able to press the pendant/clip on button.
>>
>>She lives with her parents on a small holding and likes to go see the
>>animals - parents don't like having to keep tabs as it doesn't give her
>>any independance.
>>
>>I'm sure such things exist but can't find any references as most people
>>are on the phone systems.
>>
>>Sorry to trouble you, but I thought you may be able to point me in the
>>right direction.
>
>You need to contact the BCS (British Computer Society) Disability group. An
>ex-colleague of mine, Ruben Ashkenazy designed an LCD based cpu system with
>a buzzer to remind patients to take their medication.
>
>I'll look out their number and contact details.
>
>Regards
>
>Adrian
>---
>WWW    WWW   Adrian Gothard
>WWW WW WWW   White Horse Design
>WWWWWWWWWW   +44-385-970009 (Mobile/SMS), +44-118-962-8913/4 (voice/fax)
>WWWW  WWWW   spamwhdspam_OUTzetnet.co.uk, http://www.users.zetnet.co.uk/whd
>---
>Developers of GPS satellite-based tracking systems for vehicles/helicopters
>

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