Distance from BS2 to LCD...
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Hello Everyone,
I posted this question earlier today but it hasn't shown up yet, so here it
goes again.
Can anyone tell me the longest reliable distance a serial LCD can be used
from the BS2 that's driving it? I realize that this a pretty wide open
question, greatly dependant on conditions, noise and environment, but I'm
wondering what all of you have done in this regard and what results you have
had. I'd like to use a Scott Edward's 16x2 serial LCD about 300' from the
BS2 driving it and wonder if that's possible. Your thoughts?
Thanks,
Tim
I posted this question earlier today but it hasn't shown up yet, so here it
goes again.
Can anyone tell me the longest reliable distance a serial LCD can be used
from the BS2 that's driving it? I realize that this a pretty wide open
question, greatly dependant on conditions, noise and environment, but I'm
wondering what all of you have done in this regard and what results you have
had. I'd like to use a Scott Edward's 16x2 serial LCD about 300' from the
BS2 driving it and wonder if that's possible. Your thoughts?
Thanks,
Tim
Comments
Use the 2400 baud option on the Seetron LCD.
It is possible. The longer the cable, the greater its capacitance,
so the signal edges will become less square and more rounded. If
you use a resistor between the stamp pin and the cable (say 220 ohms
for protection), that also slows down the edges. Slower baud rates
work better.
Use shielded cable if noise might be a problem. Shielding will add
some to the cable capacitance but does wonders for noise pickup.
Shielding is also a good idea if there is danger of ESD, lightning,
in the area. Ground the shield at one end only. Use a separate wire
in the cable for the data common. Remember that the 300' cable is a
big antenna.
I've had to do no more than 50 feet for an LCD display, also a
Seetron 2x16. But I've done 300 feet for data to/from sensors at
2400 baud.
If you want to get fancy, use RS422 or 485, differential line
drivers/receivers, but try the KISS approach first. An oscilloscope
can be a big help to see what is happening with the signal.
-- Tracy
>Hello Everyone,
>
>I posted this question earlier today but it hasn't shown up yet, so here it
>goes again.
>
>Can anyone tell me the longest reliable distance a serial LCD can be used
>from the BS2 that's driving it? I realize that this a pretty wide open
>question, greatly dependant on conditions, noise and environment, but I'm
>wondering what all of you have done in this regard and what results you have
>had. I'd like to use a Scott Edward's 16x2 serial LCD about 300' from the
>BS2 driving it and wonder if that's possible. Your thoughts?
>
>Thanks,
>
>Tim
Thanks for the explanation of what's going on in a case like this, that all
makes good sense. It does prompt a couple of questions about cable
shielding though. I understand grounding one end of the cable shield only,
but is there a preferred end to ground? What are criteria to base this
on? This is an exterior cable that will more than likely be buried, so
what about earth ground vs the DC ground of the system? Use it or not use
it? Tie it to the DC ground or not? I'm glad to hear that the KISS
approach may be possible and I'll give that a try before complicating
things any more than they have to be.
Tim
At 07:32 PM 4/5/2004, you wrote:
>Hi Tim,
>
>
>Use the 2400 baud option on the Seetron LCD.
>
>It is possible. The longer the cable, the greater its capacitance,
>so the signal edges will become less square and more rounded. If
>you use a resistor between the stamp pin and the cable (say 220 ohms
>for protection), that also slows down the edges. Slower baud rates
>work better.
>
>Use shielded cable if noise might be a problem. Shielding will add
>some to the cable capacitance but does wonders for noise pickup.
>Shielding is also a good idea if there is danger of ESD, lightning,
>in the area. Ground the shield at one end only. Use a separate wire
>in the cable for the data common. Remember that the 300' cable is a
>big antenna.
>
>I've had to do no more than 50 feet for an LCD display, also a
>Seetron 2x16. But I've done 300 feet for data to/from sensors at
>2400 baud.
>
>If you want to get fancy, use RS422 or 485, differential line
>drivers/receivers, but try the KISS approach first. An oscilloscope
>can be a big help to see what is happening with the signal.
>
> -- Tracy
>
>
>
>
> >Hello Everyone,
> >
> >I posted this question earlier today but it hasn't shown up yet, so here it
> >goes again.
> >
> >Can anyone tell me the longest reliable distance a serial LCD can be used
> >from the BS2 that's driving it? I realize that this a pretty wide open
> >question, greatly dependant on conditions, noise and environment, but I'm
> >wondering what all of you have done in this regard and what results you have
> >had. I'd like to use a Scott Edward's 16x2 serial LCD about 300' from the
> >BS2 driving it and wonder if that's possible. Your thoughts?
> >
> >Thanks,
> >
> >Tim
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>Yahoo! Groups Links
>
>
>
>
There are many books on the subject of cable shielding and grounding.
It is kind of a conjure art, because noise sources and forms of
coupling to your circuit live in what sometimes seems to be an
invisible parallel universe.
In the case you mentioned, where the LCD screen will be floating at
the far end of a 300' cable, it makes sense to ground the cable at
the Stamp end and not at the LCD end. It really may not make a much
difference which end (or both) is grounded. Stamp 0-5 volt signals
are pretty strong, as signals go.
The main source of noise coupling is, in effect, invisible
capacitors, picofarads, between your cabling and outside sources of
fluctuating voltage, such as power lines, weather disturbances, TV
sets, digital circuitry etc etc etc etc. It is better to terminate
all of those invisible capacitors on a shield, so that whatever
currents they produce will be shunted to ground, rather than into
your sensitive inputs. The situation is also easier when the cable
circuit is terminated by a low impedance, say 100 ohms instead of
100000 ohms. Those invisible capacitors coupling to the noise sources
will themselves have an impedance which forms a voltage divider with
the 100 ohms or 100000 ohms of your circuit. Clearly, the capacitors
cannot couple as much voltage when your circuit is low impedance.
The output impedance of your Stamp is less than 100 ohms. If you
have an oscilloscope, I suggest you look at the signal coming out of
the cable as you drag it over various potential noise sources!
The shield will be extra important with a buried cable. The
capacitance between a cable and the earth will be quite large,
especially if the earth is wet. Avoid the temptation to think of
the earth as one big uniform "ground plane". Due to presence of
power lines and weather disturbances (dramatic in the case of even
distant lightning strikes) etc, the difference in potential between
two points on earth 300 feet apart can be substantial. If your cable
shield is connected to earth ground at one end only, the shield will
shunt the capacitively coupled noise through that point. If that
cable is connected to ground at both ends, then the currents in the
shield will be higher due to the additional direct DC path.
The currents that flow in the shield are themselves a source of
magnetic coupling to the conductors inside the shield. Using twisted
pair inside the shield helps because secondary voltages induced by
the changing magnetic fields cancel out in successive turns.
Twisting also helps when the cable threads its way past power lines
or motors etc where there are substantial external AC magnetic
fields. The electrostatic shielding does nothing for magnetic fields.
Twisting is more important when the cable is grounded at both ends,
because the currents in the cable shield will be larger. Sometimes
the shield is connected to ground via a resistor or RC network
instead of directly, in order to limit currents on the shield.
Connect the shield to "earth ground" at the point at the center of a
star, assuming that describes your system with the remote LCD. The
center is the point where power lines, other cables and so forth
radiate out. Sometimes the cable shield has to be connected to
ground at both ends due to the configuration. as often there is not a
single identifiable star, or for safety or other reasons.
It is not a hard and fast rule, but usually the shield will be
connected to circuit common at one point, again near the center of
the star if the system fits that description. If not connected
together, the electrical potential of the shield will jump around
with respect to circuit common, and that in itself will couple
capacitively into the signal conductors in the cable. That shows up
as a common mode voltage Tying the shield to common at a single
point can minimize the voltage difference between the shield and the
common, but it is important to do it only an one point only, because
you don't want the shield currents to end up flowing in the common
wire. There are situations where you will not tie the shield to
common. I can't think of a good example offhand. High common mode
rejection is one good reason for using differential data transmission
(Like RS485) on a twisted pair.
I hope some of that make sense. Expect the unexpected. Often noise
reduction problems end up having off the wall causes and solutions.
-- Tracy
>Hi Tracy,
>
>Thanks for the explanation of what's going on in a case like this, that all
>makes good sense. It does prompt a couple of questions about cable
>shielding though. I understand grounding one end of the cable shield only,
>but is there a preferred end to ground? What are criteria to base this
>on? This is an exterior cable that will more than likely be buried, so
>what about earth ground vs the DC ground of the system? Use it or not use
>it? Tie it to the DC ground or not? I'm glad to hear that the KISS
>approach may be possible and I'll give that a try before complicating
>things any more than they have to be.
>
>Tim
Thank you for taking the time to provide this answer. Yes, it makes a lot
of sense. To be honest, that is exactly what I was hoping for - someone
with a lot of real life experience and skills, who would be willing to
share what they know and have seen in practice. You see, I have scratched
the surface of this subject before with other projects, but the topic
always seems to be so nebulas and difficult to nail down or assign any
rules to - for that matter, hard to find people who know very much about
it. What this boils down to, is that your explanation really means a lot,
sincere thanks to you.
I plan on using Cat5 data cable. What about running this cable through
conduit as an additional shield and protection against contact with the
ground? If you see disadvantages to metal conduit in the ground
(lightning?), how about PVC or ABS conduit for at least the physical
protection of the cable? I know that you do a lot of exterior electronics
work, maybe it's easier to just ask what your typical installation
practices are, or at least what is your typical starting point is.
Tim
At 01:39 AM 4/7/2004, you wrote:
>Hi Tim,
>
>There are many books on the subject of cable shielding and grounding.
>It is kind of a conjure art, because noise sources and forms of
>coupling to your circuit live in what sometimes seems to be an
>invisible parallel universe.
>
>In the case you mentioned, where the LCD screen will be floating at
>the far end of a 300' cable, it makes sense to ground the cable at
>the Stamp end and not at the LCD end. It really may not make a much
>difference which end (or both) is grounded. Stamp 0-5 volt signals
>are pretty strong, as signals go.
>
>The main source of noise coupling is, in effect, invisible
>capacitors, picofarads, between your cabling and outside sources of
>fluctuating voltage, such as power lines, weather disturbances, TV
>sets, digital circuitry etc etc etc etc. It is better to terminate
>all of those invisible capacitors on a shield, so that whatever
>currents they produce will be shunted to ground, rather than into
>your sensitive inputs. The situation is also easier when the cable
>circuit is terminated by a low impedance, say 100 ohms instead of
>100000 ohms. Those invisible capacitors coupling to the noise sources
>will themselves have an impedance which forms a voltage divider with
>the 100 ohms or 100000 ohms of your circuit. Clearly, the capacitors
>cannot couple as much voltage when your circuit is low impedance.
>The output impedance of your Stamp is less than 100 ohms. If you
>have an oscilloscope, I suggest you look at the signal coming out of
>the cable as you drag it over various potential noise sources!
>
>The shield will be extra important with a buried cable. The
>capacitance between a cable and the earth will be quite large,
>especially if the earth is wet. Avoid the temptation to think of
>the earth as one big uniform "ground plane". Due to presence of
>power lines and weather disturbances (dramatic in the case of even
>distant lightning strikes) etc, the difference in potential between
>two points on earth 300 feet apart can be substantial. If your cable
>shield is connected to earth ground at one end only, the shield will
>shunt the capacitively coupled noise through that point. If that
>cable is connected to ground at both ends, then the currents in the
>shield will be higher due to the additional direct DC path.
>
>The currents that flow in the shield are themselves a source of
>magnetic coupling to the conductors inside the shield. Using twisted
>pair inside the shield helps because secondary voltages induced by
>the changing magnetic fields cancel out in successive turns.
>Twisting also helps when the cable threads its way past power lines
>or motors etc where there are substantial external AC magnetic
>fields. The electrostatic shielding does nothing for magnetic fields.
>Twisting is more important when the cable is grounded at both ends,
>because the currents in the cable shield will be larger. Sometimes
>the shield is connected to ground via a resistor or RC network
>instead of directly, in order to limit currents on the shield.
>
>Connect the shield to "earth ground" at the point at the center of a
>star, assuming that describes your system with the remote LCD. The
>center is the point where power lines, other cables and so forth
>radiate out. Sometimes the cable shield has to be connected to
>ground at both ends due to the configuration. as often there is not a
>single identifiable star, or for safety or other reasons.
>
>It is not a hard and fast rule, but usually the shield will be
>connected to circuit common at one point, again near the center of
>the star if the system fits that description. If not connected
>together, the electrical potential of the shield will jump around
>with respect to circuit common, and that in itself will couple
>capacitively into the signal conductors in the cable. That shows up
>as a common mode voltage Tying the shield to common at a single
>point can minimize the voltage difference between the shield and the
>common, but it is important to do it only an one point only, because
>you don't want the shield currents to end up flowing in the common
>wire. There are situations where you will not tie the shield to
>common. I can't think of a good example offhand. High common mode
>rejection is one good reason for using differential data transmission
>(Like RS485) on a twisted pair.
>
>I hope some of that make sense. Expect the unexpected. Often noise
>reduction problems end up having off the wall causes and solutions.
>
> -- Tracy
>
>
>
> >Hi Tracy,
> >
> >Thanks for the explanation of what's going on in a case like this, that all
> >makes good sense. It does prompt a couple of questions about cable
> >shielding though. I understand grounding one end of the cable shield only,
> >but is there a preferred end to ground? What are criteria to base this
> >on? This is an exterior cable that will more than likely be buried, so
> >what about earth ground vs the DC ground of the system? Use it or not use
> >it? Tie it to the DC ground or not? I'm glad to hear that the KISS
> >approach may be possible and I'll give that a try before complicating
> >things any more than they have to be.
> >
> >Tim
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>Yahoo! Groups Links
>
>
>
>
>Hi Tim,
>In the case you mentioned, where the LCD screen will be floating at the
>far end of a 300' cable, it makes sense to ground the cable at the
>Stamp end and not at the LCD end. It really may not make a much
>difference which end (or both) is grounded. Stamp 0-5 volt signals are
>pretty strong, as signals go.
All absolutely what we do also. Good description.
However, if you still have problems, only ground the signal sending end.
That's what we do with strong noise areas. In strong signal areas, with
both ends grounded, you can get what we call a "shorted turn transformer"
type of effect. You can get circulating currents through the shield and
back through the ground and back to the shield again.
TTL may be offended at the extra capacitance and/or low impedances. There
are several brands of DTTL and TTL line drivers out there. You might
consider using one of those if you have problems.
Thank you for the additional info. I'll consider line drivers too, if I
need to.
Tim
At 09:18 AM 4/7/2004, you wrote:
>
>
>At 01:39 AM 4/7/2004, you wrote:
> >Hi Tim,
> >In the case you mentioned, where the LCD screen will be floating at the
> >far end of a 300' cable, it makes sense to ground the cable at the
> >Stamp end and not at the LCD end. It really may not make a much
> >difference which end (or both) is grounded. Stamp 0-5 volt signals are
> >pretty strong, as signals go.
>
>All absolutely what we do also. Good description.
>
>
>However, if you still have problems, only ground the signal sending end.
>That's what we do with strong noise areas. In strong signal areas, with
>both ends grounded, you can get what we call a "shorted turn transformer"
>type of effect. You can get circulating currents through the shield and
>back through the ground and back to the shield again.
>
>TTL may be offended at the extra capacitance and/or low impedances. There
>are several brands of DTTL and TTL line drivers out there. You might
>consider using one of those if you have problems.
>
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>Yahoo! Groups Links
>
>
>
>
The conduit is probably a good idea if it's not too much trouble and
the installation has to last. The worst thing is to have somebody
with a back hoe come along 6 months later and cut right through your
cable. Or have a burrowing rodent do it. Split loom tubing is also
good for mechanical protection. Metal conduit is good for shielding
and lightning protection and mechanical protection. Bury a marker
tape above it! Don't stretch the cable too much when you bury it or
pull it (use lubricant!), as individual conductors might break now or
later.
I suppose you have a good reason for ruling out a telemetry link?
The usual tradeoff is the need for power at the remote device.
Often field installations have to be cobbled together on site with
local materials. It is one thing if there is a building supply
center a few miles away, a good budget, and the installation is a
long term project in a nice open agricultural field. It is another
thing entirely if it is in a third world country 1000 miles from the
nearest hardware store, or if it is a temporary installation that
threads through a forest and up a tree. Those situations make good
stories, but not usually the best by-the-book engineering.
What are you doing with the LCD 300' from the BS2?!
-- Tracy
>I plan on using Cat5 data cable. What about running this cable through
>conduit as an additional shield and protection against contact with the
>ground? If you see disadvantages to metal conduit in the ground
>(lightning?), how about PVC or ABS conduit for at least the physical
>protection of the cable? I know that you do a lot of exterior electronics
>work, maybe it's easier to just ask what your typical installation
>practices are, or at least what is your typical starting point is.
>
>Tim
Thank you again for more good advise. I should have provided all of the
details up front. This is the well water level monitor project of a while
back, for a friend of mine. The project was put off for a while, and now
it's back on again. His shallow, open-pit style well is in the middle of
his horse pasture alongside his house and you guessed it, about 300 feet
away. The well is about 3' across and 19' deep. When the weather is hot
and rain has been a bit scarce, he often checks his water level in the
evening and decides to shower before bed if the level is up, or shower the
following morning if the water level needs some recovery time. Right now
his water gauge is a bolt on the end of a string that he lowers down to the
water surface to take a measurement. He likes this KISS system except that
the concrete well top edges are chipping away from all the activity into
and out of the well. He wants to spend as little as possible on the
project and originally did not want a remote display at all, preferring to
run out to the well each time he wanted to check the water level. The
expense had ruled out the wireless options early on. Well,(pun intended) I
had talked him into, or thought I'd talked him into, the cable remote LCD
display to be installed in the house, that we have been discussing, but he
called earlier this morning to say that he does not want to put cable in
either, (decided against digging) so the remote display is out of the
question altogether. I'm disappointed, and although I appreciate the
learning, feel like I have wasted your time, and all of you for that
matter, to some extent. I guess the discussion will end soon and the LCD
will be mounted at the well location after all. Does that make things clearer?
Tim
At 11:03 AM 4/8/2004, you wrote:
>Hi tim,
>
>The conduit is probably a good idea if it's not too much trouble and
>the installation has to last. The worst thing is to have somebody
>with a back hoe come along 6 months later and cut right through your
>cable. Or have a burrowing rodent do it. Split loom tubing is also
>good for mechanical protection. Metal conduit is good for shielding
>and lightning protection and mechanical protection. Bury a marker
>tape above it! Don't stretch the cable too much when you bury it or
>pull it (use lubricant!), as individual conductors might break now or
>later.
>
>I suppose you have a good reason for ruling out a telemetry link?
>The usual tradeoff is the need for power at the remote device.
>
>Often field installations have to be cobbled together on site with
>local materials. It is one thing if there is a building supply
>center a few miles away, a good budget, and the installation is a
>long term project in a nice open agricultural field. It is another
>thing entirely if it is in a third world country 1000 miles from the
>nearest hardware store, or if it is a temporary installation that
>threads through a forest and up a tree. Those situations make good
>stories, but not usually the best by-the-book engineering.
>
>What are you doing with the LCD 300' from the BS2?!
>
> -- Tracy
>
>
>
> >I plan on using Cat5 data cable. What about running this cable through
> >conduit as an additional shield and protection against contact with the
> >ground? If you see disadvantages to metal conduit in the ground
> >(lightning?), how about PVC or ABS conduit for at least the physical
> >protection of the cable? I know that you do a lot of exterior electronics
> >work, maybe it's easier to just ask what your typical installation
> >practices are, or at least what is your typical starting point is.
> >
> >Tim
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>Yahoo! Groups Links
>
>
>
>
Simplest solution, a simple shutoff for the pump (assuming protecting the pump
is of prime importance) ; Drawback pump shuts off in
mid shower, or washing machine filling which could lead to water heater failure.
Better solution, a horn that sounds when the water level starts getting low.
Best solution, use the X-10 protocol to transmit to an X-10 receiver via the one
leg of the pumps 220v supply and neutral. This
eliminates running a signal cable, and is cheaper than RF solutions.
Simply leave one leg of the 220v hot at all times and let the pressure switch
control the pump by breaking only one leg of the 220v.
That is how my pumphouse is wired 660FT. away.
X-10 modules run about $10-$15 and offer a good alternative to direct cable runs
when power wires are already in place.
KF4HAZ - Lonnie
From: "Timothy Medema" <timm@c
> Hi again Tracy,
>
> Thank you again for more good advise. I should have provided all of the
> details up front. This is the well water level monitor project of a while
> back, for a friend of mine. The project was put off for a while, and now
> it's back on again. His shallow, open-pit style well is in the middle of
> his horse pasture alongside his house and you guessed it, about 300 feet
> away. The well is about 3' across and 19' deep. When the weather is hot
> and rain has been a bit scarce, he often checks his water level in the
> evening and decides to shower before bed if the level is up, or shower the
> following morning if the water level needs some recovery time. Right now
> his water gauge is a bolt on the end of a string that he lowers down to the
> water surface to take a measurement. He likes this KISS system except that
> the concrete well top edges are chipping away from all the activity into
> and out of the well. He wants to spend as little as possible on the
> project and originally did not want a remote display at all, preferring to
> run out to the well each time he wanted to check the water level. The
> expense had ruled out the wireless options early on. Well,(pun intended) I
> had talked him into, or thought I'd talked him into, the cable remote LCD
> display to be installed in the house, that we have been discussing, but he
> called earlier this morning to say that he does not want to put cable in
> either, (decided against digging) so the remote display is out of the
> question altogether. I'm disappointed, and although I appreciate the
> learning, feel like I have wasted your time, and all of you for that
> matter, to some extent. I guess the discussion will end soon and the LCD
> will be mounted at the well location after all. Does that make things
clearer?
>
> Tim
Great ideas! I like the warning horn idea, and I didn't even consider X-10
-- that could be a great way to go. This is why it's good to put more
heads into a project, someone else always thinks of things that others
don't and we all benifit.
Thank you,
Tim
At 07:08 AM 4/9/2004, you wrote:
>KISS is good, but does not completely rule out convenience.
>Simplest solution, a simple shutoff for the pump (assuming protecting the
>pump is of prime importance) ; Drawback pump shuts off in
>mid shower, or washing machine filling which could lead to water heater
>failure.
>Better solution, a horn that sounds when the water level starts getting low.
>
>Best solution, use the X-10 protocol to transmit to an X-10 receiver via
>the one leg of the pumps 220v supply and neutral. This
>eliminates running a signal cable, and is cheaper than RF solutions.
>Simply leave one leg of the 220v hot at all times and let the pressure
>switch control the pump by breaking only one leg of the 220v.
>That is how my pumphouse is wired 660FT. away.
>X-10 modules run about $10-$15 and offer a good alternative to direct
>cable runs when power wires are already in place.
>
>KF4HAZ - Lonnie
>
>
From: "Timothy Medema" <timm@c
>
> > Hi again Tracy,
> >
> > Thank you again for more good advise. I should have provided all of the
> > details up front. This is the well water level monitor project of a while
> > back, for a friend of mine. The project was put off for a while, and now
> > it's back on again. His shallow, open-pit style well is in the middle of
> > his horse pasture alongside his house and you guessed it, about 300 feet
> > away. The well is about 3' across and 19' deep. When the weather is hot
> > and rain has been a bit scarce, he often checks his water level in the
> > evening and decides to shower before bed if the level is up, or shower the
> > following morning if the water level needs some recovery time. Right now
> > his water gauge is a bolt on the end of a string that he lowers down to the
> > water surface to take a measurement. He likes this KISS system except that
> > the concrete well top edges are chipping away from all the activity into
> > and out of the well. He wants to spend as little as possible on the
> > project and originally did not want a remote display at all, preferring to
> > run out to the well each time he wanted to check the water level. The
> > expense had ruled out the wireless options early on. Well,(pun intended) I
> > had talked him into, or thought I'd talked him into, the cable remote LCD
> > display to be installed in the house, that we have been discussing, but he
> > called earlier this morning to say that he does not want to put cable in
> > either, (decided against digging) so the remote display is out of the
> > question altogether. I'm disappointed, and although I appreciate the
> > learning, feel like I have wasted your time, and all of you for that
> > matter, to some extent. I guess the discussion will end soon and the LCD
> > will be mounted at the well location after all. Does that make things
> clearer?
> >
> > Tim
>
>
>
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Don't worry about wasting anyone's time discussing the project. We
are all here to learn, whether we do it by asking questions or by
sounding off. I enjoy the give and take and listening to variety of
clever situations proposed. I wish I had a peso for every project I
started or thought about and then cancelled or faded away or thought
better of.
-- Tracy
>Hi again Tracy,
>
>Thank you again for more good advise. I should have provided all of the
>details up front. This is the well water level monitor project of a while
>back, for a friend of mine. The project was put off for a while, and now
>it's back on again. His shallow, open-pit style well is in the middle of
>his horse pasture alongside his house and you guessed it, about 300 feet
>away. The well is about 3' across and 19' deep. When the weather is hot
>and rain has been a bit scarce, he often checks his water level in the
>evening and decides to shower before bed if the level is up, or shower the
>following morning if the water level needs some recovery time. Right now
>his water gauge is a bolt on the end of a string that he lowers down to the
>water surface to take a measurement. He likes this KISS system except that
>the concrete well top edges are chipping away from all the activity into
>and out of the well. He wants to spend as little as possible on the
>project and originally did not want a remote display at all, preferring to
>run out to the well each time he wanted to check the water level. The
>expense had ruled out the wireless options early on. Well,(pun intended) I
>had talked him into, or thought I'd talked him into, the cable remote LCD
>display to be installed in the house, that we have been discussing, but he
>called earlier this morning to say that he does not want to put cable in
>either, (decided against digging) so the remote display is out of the
>question altogether. I'm disappointed, and although I appreciate the
>learning, feel like I have wasted your time, and all of you for that
>matter, to some extent. I guess the discussion will end soon and the LCD
>will be mounted at the well location after all. Does that make
>things clearer?
>
>Tim
>
>
>At 11:03 AM 4/8/2004, you wrote:
>>Hi tim,
>>
>>The conduit is probably a good idea if it's not too much trouble and
>>the installation has to last. The worst thing is to have somebody
>>with a back hoe come along 6 months later and cut right through your
>>cable. Or have a burrowing rodent do it. Split loom tubing is also
>>good for mechanical protection. Metal conduit is good for shielding
>>and lightning protection and mechanical protection. Bury a marker
>>tape above it! Don't stretch the cable too much when you bury it or
>>pull it (use lubricant!), as individual conductors might break now or
>>later.
>>
>>I suppose you have a good reason for ruling out a telemetry link?
>>The usual tradeoff is the need for power at the remote device.
>>
>>Often field installations have to be cobbled together on site with
>>local materials. It is one thing if there is a building supply
>>center a few miles away, a good budget, and the installation is a
>>long term project in a nice open agricultural field. It is another
> >thing entirely if it is in a third world country 1000 miles from the
> >nearest hardware store, or if it is a temporary installation that
> >threads through a forest and up a tree. Those situations make good
>>stories, but not usually the best by-the-book engineering.
>>
>>What are you doing with the LCD 300' from the BS2?!
>>
>> -- Tracy
>>
>>
>>
>> >I plan on using Cat5 data cable. What about running this cable through
>> >conduit as an additional shield and protection against contact with the
>> >ground? If you see disadvantages to metal conduit in the ground
>> >(lightning?), how about PVC or ABS conduit for at least the physical
>> >protection of the cable? I know that you do a lot of exterior electronics
>> >work, maybe it's easier to just ask what your typical installation
> > >practices are, or at least what is your typical starting point is.
>> >
>> >Tim
>>
>>
>>To UNSUBSCRIBE, just send mail to:
>> basicstamps-unsubscribe@yahoogroups.com
>>from the same email address that you subscribed. Text in the Subject and
>>Body of the message will be ignored.
>>
>>Yahoo! Groups Links
>>
>>
>>
>>
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the
>Subject and Body of the message will be ignored.
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>
>
>
Thanks for these sentiments - I agree, we all learn and enjoy the challenges
of the variety of ideas/projects that are talked about here within our
group. It always gets the brain going.
I forgot to mention that my project will be using an ultrasonic ranging
module(the stainless steel version) to measure distance to the water surface
and the BS2 will calculate from there -- I think that will work out pretty
well. The hardware would have been finished today except that my brand-new
soldering station that I fired up for the very first time this afternoon has
a problem.... it lights up, but doesn't produce any heat. Tomorrow I'll
call the manufacturer to see if my warranty card has been delivered to them
yet and take it from there. Delays, delays.
I really have appreciated all the help from all of you who have contributed,
Tim
Original Message
From: "Tracy Allen" <tracy@e...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, April 10, 2004 3:29 PM
Subject: Re: [noparse][[/noparse]basicstamps] Distance from BS2 to LCD...
> Hi Tim,
>
> Don't worry about wasting anyone's time discussing the project. We
> are all here to learn, whether we do it by asking questions or by
> sounding off. I enjoy the give and take and listening to variety of
> clever situations proposed. I wish I had a peso for every project I
> started or thought about and then cancelled or faded away or thought
> better of.
>
> -- Tracy
>
>
>
>
> >Hi again Tracy,
> >
> >Thank you again for more good advise. I should have provided all of the
> >details up front. This is the well water level monitor project of a
while
> >back, for a friend of mine. The project was put off for a while, and now
> >it's back on again. His shallow, open-pit style well is in the middle of
> >his horse pasture alongside his house and you guessed it, about 300 feet
> >away. The well is about 3' across and 19' deep. When the weather is hot
> >and rain has been a bit scarce, he often checks his water level in the
> >evening and decides to shower before bed if the level is up, or shower
the
> >following morning if the water level needs some recovery time. Right now
> >his water gauge is a bolt on the end of a string that he lowers down to
the
> >water surface to take a measurement. He likes this KISS system except
that
> >the concrete well top edges are chipping away from all the activity into
> >and out of the well. He wants to spend as little as possible on the
> >project and originally did not want a remote display at all, preferring
to
> >run out to the well each time he wanted to check the water level. The
> >expense had ruled out the wireless options early on. Well,(pun intended)
I
> >had talked him into, or thought I'd talked him into, the cable remote LCD
> >display to be installed in the house, that we have been discussing, but
he
> >called earlier this morning to say that he does not want to put cable in
> >either, (decided against digging) so the remote display is out of the
> >question altogether. I'm disappointed, and although I appreciate the
> >learning, feel like I have wasted your time, and all of you for that
> >matter, to some extent. I guess the discussion will end soon and the LCD
> >will be mounted at the well location after all. Does that make
> >things clearer?
> >
> >Tim
> >
> >
> >At 11:03 AM 4/8/2004, you wrote:
> >>Hi tim,
> >>
> >>The conduit is probably a good idea if it's not too much trouble and
> >>the installation has to last. The worst thing is to have somebody
> >>with a back hoe come along 6 months later and cut right through your
> >>cable. Or have a burrowing rodent do it. Split loom tubing is also
> >>good for mechanical protection. Metal conduit is good for shielding
> >>and lightning protection and mechanical protection. Bury a marker
> >>tape above it! Don't stretch the cable too much when you bury it or
> >>pull it (use lubricant!), as individual conductors might break now or
> >>later.
> >>
> >>I suppose you have a good reason for ruling out a telemetry link?
> >>The usual tradeoff is the need for power at the remote device.
> >>
> >>Often field installations have to be cobbled together on site with
> >>local materials. It is one thing if there is a building supply
> >>center a few miles away, a good budget, and the installation is a
> >>long term project in a nice open agricultural field. It is another
> > >thing entirely if it is in a third world country 1000 miles from the
> > >nearest hardware store, or if it is a temporary installation that
> > >threads through a forest and up a tree. Those situations make good
> >>stories, but not usually the best by-the-book engineering.
> >>
> >>What are you doing with the LCD 300' from the BS2?!
> >>
> >> -- Tracy
> >>
> >>
> >>
> >> >I plan on using Cat5 data cable. What about running this cable
through
> >> >conduit as an additional shield and protection against contact with
the
> >> >ground? If you see disadvantages to metal conduit in the ground
> >> >(lightning?), how about PVC or ABS conduit for at least the physical
> >> >protection of the cable? I know that you do a lot of exterior
electronics
> >> >work, maybe it's easier to just ask what your typical installation
> > > >practices are, or at least what is your typical starting point is.
> >> >
> >> >Tim
> >>
> >>
> >>To UNSUBSCRIBE, just send mail to:
> >> basicstamps-unsubscribe@yahoogroups.com
> >>from the same email address that you subscribed. Text in the Subject
and
> >>Body of the message will be ignored.
> >>
> >>Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >
> >
> >
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> >from the same email address that you subscribed. Text in the
> >Subject and Body of the message will be ignored.
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
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>
>
>
>