[OT]Question on X10 devices

Hi.

   I read about the X10 system online and I'm quite interested in it. For some very slow speed communication
system, I think this is probably a better system compared to CAN bus or LIN bus, since only two wires are
necessary to transmit both data and power at the same time. 
   The schematics on the second link looks pretty complicated because it must meet some industrial
standards. For personnel interest,  I wonder if someone may show me some similar but simple way on
transmitting some high frequency "glitches" as digital data via small AC or DC power lines?

http://en.wikipedia.org/wiki/X10_(industry_standard)

ftp://ftp.x10.com/pub/manuals/technicalnote.pdf
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Re: [OT]Question on X10 devices

What do you want to transmit?

X10 is extremely limited, it's actually noticeably slow to transmit the
address and on/off command.

Transmitting as high freq "noise" on the signal may interfere with other
devices constantly. There is also competition for recognizing that
signal against other noise.

Danny

gardenyu wrote:
>  
> Hi.
>  
>    I read about the X10 system online and I'm quite interested in it. For some very slow speed communication
system, I think this is probably a better system compared to CAN bus or LIN bus, since only two wires are
necessary to transmit both data and power at the same time. 
>    The schematics on the second link looks pretty complicated because it must meet some industrial
standards. For personnel interest,  I wonder if someone may show me some similar but simple way on
transmitting some high frequency "glitches" as digital data via small AC or DC power lines?
>  
> http://en.wikipedia.org/wiki/X10_(industry_standard)
>  
> ftp://ftp.x10.com/pub/manuals/technicalnote.pdf
> _________________________________________________________________
> MSN 中文网，最新时尚生活资讯，白领聚集门户。
> http://cn.msn.com

[EE] A few days work for a Technician / Engineer / Student in New York city

Available (maybe):

A few days basic mechanical / electrical hands on work.
Boring and repetitive .

Location:  New York City or nearby.

_________

I MAY have a requirement in the immediate future for a technician (even an
engineer would suffice  )(and a competent student may be as good as any
if they had the time available) in or near New York city.

Technical level of work is yet to be decided but may be not much more
than the ability to use a
screwdriver and to demonstrate a good level of common sense and reliability.
May be up to a weeks work - possibly half that.

Payment - as little as possible and as much as necessary.

If possibly interested please contact me OFFLIST at MKBStechnology <at> gmail.com
(NOT to this email's send address.)

     SME
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RE: [OT]Question on X10 devices

Sorry, I mistakingly used the phrase "high frequency".

but X10's frequency is always like 60Hz or 120 because it only appears on zero crossing edges.

> Date: Sun, 30 Nov 2008 23:29:09 -0600> From: dannym <at> austin.rr.com> To: piclist <at> mit.edu> Subject: Re:
[OT]Question on X10 devices> > What do you want to transmit?> > X10 is extremely limited, it's actually
noticeably slow to transmit the> address and on/off command.> > Transmitting as high freq "noise" on the
signal may interfere with other> devices constantly. There is also competition for recognizing that>
signal against other noise.> > Danny> > gardenyu wrote:> > > > Hi.> > > > I read about the X10 system online and
I'm quite interested in it. For some very slow speed communication system, I think this is probably a
better system compared to CAN bus or LIN bus, since only two wires are necessary to transmit both data and
power at the same time. > > The schematics on the second link looks pretty complicated because it must meet
some industrial standards. For personnel interest, I wonder if someone may show me some similar but
simple way on transmitting some high frequency 
 "glitches" as digital data via small AC or DC power lines?> > > >
http://en.wikipedia.org/wiki/X10_(industry_standard)> > > >
ftp://ftp.x10.com/pub/manuals/technicalnote.pdf> >
_________________________________________________________________> > MSN
中文网，最新时尚生活资讯，白领聚集门户。> > http://cn.msn.com> 
_________________________________________________________________
MSN 中文网，最新时尚生活资讯，白领聚集门户。
http://cn.msn.com

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Re: [PIC] Garbage out of UART after "reset" instruction -- weird fix

"William "Chops" Westfield wrote:
>>> 'm still confused over why I don't get
>>> garbage after a power-on reset. The chip spits out garbage only after
>>> executing the reset instruction.
>
> If an UART is receiving data continuously, and the sender "glitches"
> in the middle of a character but begins transmitting continuously
> again, they can remain "out of sync" indefinitely, and the receiver
> sees garbage.  Async needs a period of a bit more than 1 character
> time in the Mark (idle) state to get things synchronized again.
>
> (You didn't say whether the line was continually transmitting, but
> I've seen this happen before.  Usually on some sort of data line that
> has continuous data, when the receiver reboots and initializes its
> uart in the middle of the stream.)

Olin, Bill: thank you for your insight, it suggested another way to find out 
what's going on.

The line is not transmitting continuously, but it does echo back characters 
that it receives on RS232. So it's conceivable that the last character 
echoed (<CR>) is still being transmitted, when the PIC resets, and sends the 
welcome string. A circuimstancial piece of evidence in support of the theory 
is that I do recall the number of characters in the "garbage" string being 
roughly the same as in the real string.

Olin's suggestion would be the proper way to handle the problem, but a 
quick-and-dirty way to conclusively prove the above theory, would be to 
insert a delay before the reset instruction (this would give the UART enough 
time to finish transmitting the echo).

Re: [OT]Question on X10 devices

gardenyu wrote:
> Sorry, I mistakingly used the phrase "high frequency".
>  
> but X10's frequency is always like 60Hz or 120 because it only appears on zero crossing edges.

You might want to look at these:

http://www.linuxha.com/common/mTW523/sniffer.html
http://www.linuxha.com/common/mTW523/index.html
http://www.linuxha.com/common/mTW523/mtw523.html

The last one discusses the bits and things. You're looking at a
data rate less than 50 bps (that's from memory). X10 has some real
reliability problems (beside being slow) that you should get used
to. They can totally shut down X10 signals from getting through.

-- 
Linux Home Automation         Neil Cherry       ncherry <at> linuxha.com
http://www.linuxha.com/                         Main site
http://linuxha.blogspot.com/                    My HA Blog
Author of:    	Linux Smart Homes For Dummies
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Re: [OT]Question on X10 devices

On Mon, Dec 1, 2008 at 12:35 PM, gardenyu <gardenyu2004 <at> hotmail.com> wrote:
>   I read about the X10 system online and I'm quite interested in it. For
> some very slow speed communication system, I think this is probably
> a better system compared to CAN bus or LIN bus, since only two wires
> are necessary to transmit both data and power at the same time.

I do not know much about X-10. But I think ASi bus can be
interesting as well. It also uses 2 wire cable for data and
power (up to 8A!). But you do need to use ASICs for it.
http://www.as-interface.net/System/Facts
http://en.wikipedia.org/wiki/AS-Interface

HART is similar and use 2-wire for both the analog 4-20mA
signal and the digital signal.
http://www.hartcomm.org/
http://en.wikipedia.org/wiki/HART_Protocol

Xiaofan
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Re: [EE]:: SMD switch mounting reliability - comments sought

>> The manufacturer wants to change to a surface mount switch.
>> I'm a bit dubious about the probable longevity of the mounting if solder
>> alone is used. Adhesive could be added as a backup.

> Totally isolate and buffer the external force from the button using an 
> elastic
> lever (fulcrum) with the button and the booth acting on different parts of 
> the
> fulcrum.

Probably  agood idea, but not an easy option here. I largely have power of 
veto or agreement. "Fancy" alternatives are fairly largely not an option.

If/when this gets re-engineered it will quite possibly get a magnet and Hall 
switch solution. Even an optical interuption system could be 'interesting' 
but the Hall sensor does give you full environmental isolation. Cost is the 
standing current (smallish with some duty cycle multiplexed versions) and 
cost of the sensor IC - which tends to be dearer for the multiplexed 
versions. Reed switches have no standby power needs but reliability is 
generally not stunning. I have seen some cheap consumer level Chinese 
manufactured products with magnet and reed-switch switches.

          Russell

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RE: [EE]:: SMD switch mounting reliability - comments sought

> >> The manufacturer wants to change to a surface mount switch.
> >> I'm a bit dubious about the probable longevity of the mounting if
solder
> >> alone is used. Adhesive could be added as a backup.
> 
> > Totally isolate and buffer the external force from the button using an
> > elastic
> > lever (fulcrum) with the button and the booth acting on different parts
of
> > the
> > fulcrum.
> 
> Probably  agood idea, but not an easy option here. I largely have power of
> veto or agreement. "Fancy" alternatives are fairly largely not an option.
> 
> If/when this gets re-engineered it will quite possibly get a magnet and
Hall
> switch solution. Even an optical interuption system could be 'interesting'
> but the Hall sensor does give you full environmental isolation. Cost is
the
> standing current (smallish with some duty cycle multiplexed versions) and
> cost of the sensor IC - which tends to be dearer for the multiplexed
> versions. Reed switches have no standby power needs but reliability is
> generally not stunning. I have seen some cheap consumer level Chinese
> manufactured products with magnet and reed-switch switches.

The 'cheap but perfectly adequate' LED bike lights use a magnet & reed
switch arrangement now.  Random eBay auction <
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=120341714872> or
<http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=110320225950> if you

Re: [PIC] Garbage out of UART after "reset" instruction -- weird fix

Vitaliy wrote:
> Olin's suggestion would be the proper way to handle the problem, but a
> quick-and-dirty way to conclusively prove the above theory, would be
> to insert a delay before the reset instruction (this would give the
> UART enough time to finish transmitting the echo).

The real thing is both simpler and more reliable than a delay, and would
better prove that's what the problem really is:

         banksel txsta
wait_udone                   ;wait until UART done sending last char
         btfss   txsta, trmt ;UART idle yet ?
         jump    wait_udone  ;no, go back and check again
         reset

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