Searching \ for '"Plant out of water project"' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=plant+out+water
Search entire site for: '"Plant out of water project"'.

Truncated match.
PICList Thread
'"Plant out of water project"'
1999\05\10@044830 by Benjamin Petersen

flavicon
face
I have an (old) idea for a new pic project.
I would like to attatch this device to a plant and make it beep when the
plant needs water.

I was thinking about using :
1 3v litium batt
1 PIC12c508
1 Pizo-beeper
2 metal pins pluged into the plants pot (or what ever you call it)

I would like to make some kind of A/D converter, and as far as i can recall
it can be done with a cap and a res.
And something with pulsing an output and reading an input.I was thinking
that the water alarm should NOT beep during the night, messured either by an
internal clock or by a photosenser. Dryness alarm should be dynamic.

When this project is done it will ofcause be public.

Regards
Benjamin Petersen

1999\05\10@055206 by Michael Rigby-Jones

flavicon
face
Make sure you use AC to measure the resistance.  The probes will corrode
very quickly otherwise.  Maybe a pushbutton to calibrate the device for wet
and dry states?  How about making the probes on flying leads so that you
could connect several plant pots in series?

Regards

Mike Rigby-Jones

> {Original Message removed}

1999\05\10@063809 by Henrik HolmgŒrd

flavicon
face
I would use a opamp configured as a comperator to measure the resistance
between two electrodes in the Plant pot. By using this approach you will
have a 0 or 5 v signal to the 12c508, and you can add a pot to adjust the
sencivity of the moist sensor.

Regrads Henrik Holmgaard

> {Original Message removed}

1999\05\10@074111 by Seyler Jean-Yves

flavicon
face
I used such a thing, several years ago, but with some CD4000 glue :

- 1st : generate a square wave (# kHz)
- apply it through a capacitor (-> no continuous voltage applied so no
electrolytic corrosion) to a "combed-shape" printed circuit
- read the rectified AC voltage (through a diode doubler)
- test (via a Schmitt trigger) if higher than the threshold
- That's all

It is installed on my rough-top for several years to close my
roof-window if it begins to rain (very usefull in summer if a storm
begins during our sleep :-)

It should be easy to do it with a 12C508 although you could hardly set
threshold (or perhaps via frequency variation ?)

Hope it could help ...
Tell us the result of your brainstorming ;-)

Jean-Yves
>
>> {Original Message removed}

1999\05\10@100251 by Lawrence Lile
flavicon
face
Problems I encountered when I built one of these:

1.  Soil resistance changes over time.  I would plug my two probes into the
wet soil, then an hour later it would start beeping.  I made a little
circuit to plot this on my datalogger, and noticed a dramatic change in soil
resistance.  Of course I was measuring with an AC signal to prevent
corrosion.

2. You can buy other people's attempts at doing this, that also don't work,
at dimestores for $4.00.  See Consumer reports, early this year.

3.  I made a real nice cricket chirp, and made a resistance measurer using
AN512 style RC timer measurement.   Can't find the code anymore, so I
must've erased it in disgust.






{Original Message removed}

1999\05\10@113203 by John Mitchell

flavicon
face
On Mon, 10 May 1999, Benjamin Petersen wrote:

> I have an (old) idea for a new pic project.
> I would like to attatch this device to a plant and make it beep when the
> plant needs water.

Check out Stephen Bolt's "Green Thumb", it's *very* similar to your
suggestion, but much simpler:

       http://www.xs4all.nl/~sbolt/e-groeneVinger.html

His site also describes other interesting projects: very low power BEAM
robots, and a "spider" that uses an IR sensor/emitter as a form of radar!


- j

1999\05\10@153320 by Martin McCormick

flavicon
face
       There was a researcher in Canada in the late eighties who said
that plants gave off ultrasonic sounds when they were running low on
water.  The Radio Canada interview about this topic made some humorous
statements about the plants crying out because of their thirst, but
the serious theory was that the sounds had to do with the mechanics of
fluid flow in the plant's capillaries.  The researcher at the time was
using a Commodore C64 as the controller for the experiment and the
sounds that it emitted when the plant was out of water were computer
generated using the C64's sound chip.

       I heard all of this over 10 years ago so I have forgotten the
details, but if there is anything to the ultrasonic theory, this might
be a thought.

       I smile with sick glee as I think of the millions of weeds in
our yard which will be howling their little selves to death in July
and August during the dry time.  Oh!  the botany!

Martin McCormick WB5AGZ  Stillwater, OK
OSU Center for Computing and Information Services Data Communications Group

1999\05\10@182931 by paulb

flavicon
face
Lawrence Lile wrote:

> Problems I encountered when I built one of these:
> 1.  Soil resistance changes over time.  I would plug my two probes
> into the wet soil, then an hour later it would start beeping.  I made
> a little circuit to plot this on my datalogger, and noticed a dramatic
> change in soil resistance.  Of course I was measuring with an AC
> signal to prevent corrosion.

 Do I take this to mean that the (continuous) measurement current (AC
notwithstanding) is causing "polarization" at the electrodes, drying the
soil locally?

 Surely the advantage of the 12C508 is the ability to sleep most of the
time (and even then, execute the test cycle only every so many
"sleeps",) and apply current and make a measurement only every five
minutes or so?
--
 Cheers,
       Paul B.

1999\05\11@023736 by : Cassie Carstens

flavicon
face
> I would use a opamp configured as a comperator to measure the resistance
> between two electrodes in the Plant pot. By using this approach you will
> have a 0 or 5 v signal to the 12c508, and you can add a pot to adjust the
> sencivity of the moist sensor.
>
> Regrads Henrik Holmgaard
A LDR arangement could be fitted to this opamp configuration to meet
your demand 'not to beep when it is dark' Cool, just switch the light
off when it squeels for water...........
Regards Cassie.
>
> > {Original Message removed}

1999\05\11@044550 by Brian Jones

flavicon
face
Just made one of these for local Guides (Girl Scouts) project. No
PIC though :-(

Just one NPN transistor as a switch, a biasing resistor, LED, 3v
batteries and two paper clip probes. No soldering - all screws into a
4 hole pice of terminal block. If I remember right a 6K8 resistor was
about right to turn LED on if probe resistance was greater than 15K
which seemed to be a reaonable wet/dry point for my house plants.

[Completely OT] - I am looking for ideas for projects to make with
youngsters. Rules are - must screw into terminal block (ie
resistors, caps, diodes,etc and 3 legged devices such as
transistors are OK, larger SIP and DIP devices are not, buzzers,
speakers, batteries, mikes etc OK - I know I'll have to solder leads
for them). Must be fairly simple (say 4 transistor or equivalent
maximum) and must be fairly easy to explain. Since this is so [OT]
replies directly to my reader please. Any ideas may possibly get
included in a booklet for Scouts and Guides.

Brian

















Replace the probes with a reed switch and the LED with a buzzer,
put a magnet to hold reed switch on and hey -prestoi a burglar
alarm.

Brian E Jones
Centre for Java Technology
IBM HURSLEY

1999\05\12@104259 by Lawrence Lile

flavicon
face
-----Original Message-----
From: Paul B. Webster VK2BZC <spam_OUTpaulbTakeThisOuTspammidcoast.com.au>
To: Lawrence Lile <.....lilelKILLspamspam@spam@toastmaster.com>; PICLISTspamKILLspamMITVMA.MIT.EDU
<.....PICLISTKILLspamspam.....MITVMA.MIT.EDU>
Date: Monday, May 10, 1999 5:27 PM
Subject: Re: "Plant out of water project"


{Quote hidden}

Paul; Replied
>  Do I take this to mean that the (continuous) measurement current (AC
>notwithstanding) is causing "polarization" at the electrodes, drying the
>soil locally?
>

I never did understand the phenomemon completely.  I set up a 12C508 so it
sleeps, takes a measurement, sleeps, etc. etc., and it would invariably
alarm after an hour, even in obviously wet soil.  A profile of the soil
resistance over time looked suspiciously like an exponential RC charge curve
(although many things in nature exhibit exponential behavious and this
resemblence proves nothing) .  It was wierd.




>  Surely the advantage of the 12C508 is the ability to sleep most of the
>time (and even then, execute the test cycle only every so many
>"sleeps",) and apply current and make a measurement only every five
>minutes or so?
>--
>  Cheers,
>        Paul B.

I wish this had worked.

More... (looser matching)
- Last day of these posts
- In 1999 , 2000 only
- Today
- New search...