wathering system garden

[LogiSoft]

Hello,

I have to make with the homeserver and a theben weather station a logical function for an automated wathering system for a garden.

With a sequenz I can open every valve and so.

My problem is WHEN do I have to give the garden water and for how long?

When it has rained for more than xx minutes and the temperature is above xx °C? what do I have to do in winter and so on.

Has anyone done this before ?
What kind of logic have you used for it ?

Thanks for your help.


PS: You may answer in German (Deutsch)

[PeterPan]

Hello Collegue..

Without a Soilhumidity-Sensor, you must do a silly automatic every day:

-> If it did not rain the hole day, start water pump at 9:45 O`clock and Stop it at 10:00.

Thats it.

Best regards
peterpan

[Gaston]

Well Basically you should talk first to a "green" expert, so best the company which "installed" or "delivered" your garden about how to water what in it. Especially for the grass they will most probably come up with a figure per square meter and with some rules.

These rules need now to be implmented into th logic.

For the grass:

The duration of watering for the different circuits then depends on the surface it is watering. Lats say "V" is the number of litres you need per square meter. The easies method is that you add up the throughput of each sprinkler in the circuit (litre/sec) and then devide it by the surface this circuit does cover in total. So you get a figure "d" in l/sec*m^2). Now you have to chose a time t so that t*d=V, so t=V/d in seconds.

This must be done for each circuit.

The "problem" is that not each sprinkler in the surface has the same throughput and/or surface it covers. Let's say you hve two sprinkler both with 5 liter/sec. But one covers 5 auqremeters and the other 10 square meters. This means that in reality the first one gets 1 l/s per suqaremeter, while the other only get half of it.

So when you get th e"t" figure above best is to check the different sprionklers and se what the difference would be for each. Then you may adjust "t" in accordence to what the gardner says (i.e. better to get to much water, or better to get less water). If more water is ok, you may select t for the sprinkler where the throughput/m^2 ist the lowest instead of the whole circuit. Else you may choose it for the highest, or you may chose something in between.

For flowers it is somewhat the same, but here it depends on the system used (perforated hose, small sprinklers). For the hose for example the length is replacing the surface as for the grass.

Best regards,
Gaston

[PeterPan]

That`s Great! Delicious!

Is it that easy to do a wateringsystem?

What about the Watertemperature? And the Airhumidity? Would it be also interesting to get the middlevalue of the pressure in the tubes? And also you might need an MotionDetector to shut down the water. The guy does not want to get wet in while he is extremeBBCing.

:) :) :beer:

Dry Regards
PeterPan

[Gaston]

What about the Watertemperature? And the Airhumidity? Would it be also interesting to get the middlevalue of the pressure in the tubes? And also you might need an MotionDetector to shut down the water. The guy does not want to get wet in while he is extremeBBCing.


Oh Peter, superb remark, and so constructive :rolleyes: If you have a personal problem with me the forum is not th ecorrect place to show this.

But yes lets tell the people all they can do (or all we do) with EIB is open valve-wait-close valve. Great deal EIB, isn't it. People will think if it is worth it...

I have simple opened a wider horizont. If you do not want to extend you horizont thats not my problem, but I do certainly not deserve such a ridicoulous remark for doing so.

[PeterPan]

Hi Gaston...
I like your excellent writing and calculations about all that things that are physically arround if somebody has a problem that needs to be solved.
I am shure that i am not the onlyone that luvs to read about your tasks. The Day is saved if there is one.
Personally, i would do it easier. Because there is something that is called "healthy Human Understanding".
And a Professor i liked very much did show 20 Minutes to the class on the Board how a mathematics would calculate a simple problem like "Sinus-Wave" or "The Volume of a Ball".
After 20 Minutes he took a spoon and cleaned the Board and wrote the formula with the words "Anything else can be neglected!"
But if anybody has got the time and sparetime he may calculate as long as he wants. "But nobody will pay for this time".

At this explicite example:
The Guy "LogiSoft" has got:
- Homeserver
- Theben Wheatherunit
So he is able to do a
- Logical-Array (HS)
and gets the Values for
- Temperature
- Wind
- Brightness

What we do not have is
- How much Squaremeters
- What kind of Sprinklers are used
You tell the Guy about:
- Surface in Squaremeters
- Liter/Sec Output of the Sprinklers
- But the Sprinklers are not all the same
- For Flowers there might be a performed Hose.

But by all the Calculation there is a Point that impacts most: Loose soil or Hard Soil?
Also the two things i told you before:
- Watertemperature and
- Airhumidity

If the water has got for example 20 Degrees and an Airhumidity something like 45%, the "warm" water will expire easier, than by 10 Degrees Watertemp. and 80% Airhumidity.
But dont calculate or tell a Formular for this.

Because nothing beats harder than hard Soil!
--> It doesn`t matter how much water you spend on hard soil, it will flow away and the Roots of your plants will never feel the freshness of Water!
So keep cool and go on writing.. :cool:

Best Regards
PeterPan

[Gaston]

But by all the Calculation there is a Point that impacts most: Loose soil or Hard Soil?
Also the two things i told you before:
- Watertemperature and
- Airhumidity


Well thats what your Professor ment by what could be neglected :D

About your post I must admit that its very hard to determine if it is sacarstic or not. Your second answer then seems to show that it was not ment to be sacarstic and on teh other hands gets sacarstic agan. Not that I hate sacarsme but I thought we were in a technical forum and not in a retoric one. So lets keep to things and lets not try to manipulate peaple with sacarsme (I know this was never your intention ;), well that the rukle number one of sacarsme )

You know that I really like these calculations and that I'd loved to include them (would have taken some more time to setup the formulaes).

However one has to read exectely what I write ;)

I said that one has to ask a specialist about the topic (gardner, etc...) as I am really far from being one on this topic. And then one has to implement the "algorithm" that the specialist tells you. If he says something about moisture, or temperature of Water etc...well then it must be included.

Basically he will always tell you at least to water a certain amount of water per sqare meter for the grass. The amount is normaly not bound to temperature as for what I heard to date. So I did only pick this to say to what one has to pay attention while setting up such a thing because in the worst case you can have some places that get overflooded or others are dry if the difference in thrughput or surface is quite different.

For the rest I am not a Grasswatering expert and as I said in numerous other threads I do only write in afirmative form about topics I really know.

Best regards,
Gaston

[thieleks]

at some time not so far in future this very day will be remembered as the beginning of WW III - Watering War III. :eek:

One could really be glad that Switzerland and Luxembourg are separated by Germany wich hopefully will stick to its neutral position :)

Hey, you guys - slow down a little bit. We love BOTH of you!

Sincerely Yours,

Klaus-Peter

[Gaston]

@ Klaus-Peter
In my eyes everything is calmed down again. On the other side we were only in first gear yet, and with both feets on the brake, anyway. :p

sorry, couldn't resist :D

Cheers,
Gaston

[LogiSoft]

And also you might need an MotionDetector to shut down the water. The guy does not want to get wet in while he is extremeBBCing.


That's not possible. The garden is too big.

SOLUTION: watering at 05.00 when everybody is sleeping.

I still do not have a solution for the logic to use with the homeserver and the theben weatherstation.

maximum day temperature and no rain for that day:
below 0°: NO WATHERING (freezing)
below 10°: once in a week ?? (winther months)
below 20°: 3x a week ??
above 20°: every day ???

duration of wathering in function of the temperature:
in winter 5 minutes; in summer 15 minutes per zone ?

[PeterPan]

... if there are no neighbours and the Inhabitants have got a deep sleep! Or you save the Bell ;-)

In mine Opinion with that Timetable you won`t get it.

With your Constellation of Devices i would do it like this:

Any Day (Mo-So) AND March to October AND Temperature more than 16 Degrees
- If it did not Rain from 0:00 to 23:59 AND is not raining till 21:45, then watering ON for xx Minutes the next day (start at 21:45)

So you just have to guarantee, that there is no Watering, if there is a gardenparty (motiondetector?) :D

xx = Time to get the Mosture in right condition

For anybody who is reading this: It is not the best solution. The best way is to get an information on a Mosture-Humidity-Sensor.

http://www.rts-automation.de/.img/ar.118.pictsmall.jpg
This for example is an EIB-Soil-Humidity-Sensor by RTS. That`s the professional way.
http://www.rts-automation.de/?REM_site=10&suaid=118

Ok, EIB-handicraftsman it is also possible to measure the Resistance or Capacity with selfmade devices with Parts by Conrad. :-)

Best Regards
PeterPan

[Gaston]

http://www.rts-automation.de/?REM_site=10&suaid=118[/URL]


What I really don't like about this moisture sensor is the operating range wich goes only down to 0°C. And ist well the operation range not the measuring range. This would yell for it to be dismounted each winter.

Well, noboday will do so, I guess, and most probably it will work, neverless I do not understand how an outside sensor can be given such specifications.

Best regards,
Gaston

[PeterPan]

Hi Gaston..

The Sensor above has be sticked into the soil to measure the humidity, right?

What happens to wet soil below 0 Degrees? And what will happen to the water inside the Sensor-Tube?

So in mine experience the water in the soil becomes ice. Ice has got an bigger volume than water. The Sensor-Tube is made of plastic. So it will happen the same thing, as it happens if you will leave Water in an Metal-Tube outside by Temperature below 0 Degrees. *crack*, doesn`t it?

Do you think my explanation is correct?

Best Regards
PeterPan

[Gaston]

Do you think my explanation is correct?


Yes, of course it is. However, on the other side, if it is correct it emphases the fact that the tube would need to be deinstalled during Winter.

For me it is unimportant how the moisturing sensor works (infact I do not really know how this sensor works as I never got one in my hands). There are many ways to avoid any damage done by freeziung water like a pressurized balloon in teh tube with an extension chamber. So the world is not so easy as it might seem at first glance ;)


But my thinking is diferent anyway:

This sensor and especially the tube is for outside use. Right ? Outside temperature can drop below 0°C, and this is not an unexpected exception. Right ? What is written in the documentation ? Minimum operating temperature is 0°C. Right ?

So what happens when the temperature drops below 0°C ? Bang, its no longer suited for outside use :(

Before others response wih wrong statements: The documentation states "operating temperature", wich is the range of temperature whjere the device can be operated. I understand very well that the measuring range will stop at 0°C, but if operating and measuring range are different they MUST be stated as such. As it is for the moment it means that the sensor CANNOT be operated below 0°C, and thus must be deinstalled in winter.

So, I can imagine that this is a documentation issue only.

Next year I will have to buy such a sensor, and latest at that time I will contact RTS for enlightment on the topic.

For anybody wanting to buy this sensor, I strongly recommend to contact RTS upfront to get this clarified.

Best regards,
Gaston

[LogiSoft]

Maybe you can leave the sensor in the ground when it's below 0°C but it's not giving signals on the bus.

[Gaston]

Maybe you can leave the sensor in the ground when it's below 0°C but it's not giving signals on the bus.

Hi Logisoft,

You may not know me yet :D , but I do not like to speculate but on topics where only speculation is possible because no information is available. And even then my spaculations have usually followed a underlying analysis first.

Here ist clear: The documentations states an "operating temperature range" (Betrioebstemperatur), which is the range of temperature in which the device can be operated, by definition. Any operation outside these bounds may for exampe void the warranty.

These are the facts. Now as said, possibly this is an error of documentation, because this may not be the operating range which is ment but the measuring range.

You may for example have a operating range from -20°C...70°C but a measuring range from 0°C...70%C. Well in german as the sensor is not measuring a temperature it would be calles "Arbeitsbereich" (Operational range, which is different from operating range) better then "Messbereich" (Measuring range), but never.

In the Datasheet this Temperature is clearly stated as operating temperature (Betriebsumbegungsstemperatur).

And there is no need to speculate any further as I am sure the RTS-Automation (http://www.rts-automation.de/?REM_site=2) will be glad to clarify this.

Best regards,
Gaston