I like fresh herbs I'm not a picky eater
otherwise but add in some fresh basil
cilantro rosemary or thyme to a meal and
it just makes a huge improvement to any
recipe so I pay for this stuff at the
grocery store and some of it is
expensive like two to four bucks for a
few stems so I got that thinking this
spring hey I've got a backyard on the
south side of my house I've got the
Internet to read up on how to grow
things I can do this myself and save
some money and then the engineer and me
realized hey have you made the garden
automatically water itself that could
save some work and if you collected all
sorts of different data you could
analyze that and get a sense of the
health of the garden without any
guesswork well here's a tip if you spend
a lot of time and money complicating
your garden with a bunch of sensors and
electronics it ends up being more worth
it just to buy fresh herbs from the
grocery store my brother bought me an
Arduino for Christmas last year saying
it was right up my alley I guess he
thought I could do with a few more ones
and zeros in my life and being a cat
owner myself I have to admit that it
might be nice to have something that
does what I tell it to well I went
through the tutorials and I honestly had
a lot of fun with this thing the
gratification that comes from combining
a working circuit and a working program
is a little bit addicting very much like
golf these moments of Eureka occur in
between long bouts of failure
disappointment and constant hazards but
you get something right just frequently
enough to keep you from giving up on it
altogether and I'm almost as nervous as
they come for an electrical hobbyist not
to mention as a gardener so if you're
treating this as a how-to guide don't
sign up for a booth at the farmers
market just yet in the interests of
keeping this video interesting I'm gonna
try and keep most of the technical
jargon and minutiae of the project out
of the narration and in the description
below if you have specific questions
that don't get addressed I'd love to
answer them in the comments let's jump
right into this building I'll go through
all the individual parts as if an
Arduino isn't complicated enough
there are a whole host of shields which
are just boards you can put on top of an
Arduino that add additional
functionality like Mario power-ups I'm
using this data logging shield which
allows you to save to an SD card now it
is completely possible to automatically
water a garden without any data login
whatsoever but then again none of this
is really necessary and I'm starting to
realize already that the plants
themselves are becoming secondary to the
garden data in my mind because if I
don't have a heavily instrumented garden
I might not be able to see how sunlight
illuminance correlates with soil
temperature or how soil moisture changes
with relative humidity and air
temperature or how far out of phase and
soil temperature in air temperature are
from one another and I certainly
wouldn't be able to take all that data
and make cool graphs and if I'm being
honest now I'm realizing this is truly
what's important to me I want to make
cool graphs this shield comes 95%
assembled but the headers are left off
and this is allegedly so you can choose
which headers you want but I have an
inkling that this is kind of like a mini
gauntlet for an electrical hobbyist like
Adafruit saying only after you can
solder on these headers will you be
ready for whatever it is you're planning
to do with this board and as someone who
uses their $10 soldering iron primarily
for burning their initials into the
bottom of wooden bowls this was a
disaster of a soldering job and I won't
show any close-ups of it because I'm
embarrassed but I somehow finished it
without ruining the board let's talk
about sensors I wanted a good mix of
data so I chose a suite of several
different kinds of sensors first and
foremost I wanted a soil moisture sensor
because I needed to know when to water
the garden now I did a lot of research
on soil moisture sensors and I won't
bore you with the details because
there's a lot of discussion out there so
let me save you some trouble in the
simplest way I can think of you get what
you pay for
there's more on this in the description
below if you're interested I bought a
capacity of soil moisture since
from veget Ronix and i couldn't resist
getting their soil temperature sensor
while I was at it these sensors are
quite a bit more expensive than the
typical stuff you can find on sparklin
or Adafruit but again you really get
what you pay for
these are well-built well calibrated and
very simple to use
here I'm testing the soil temperature
sensor I also tested the soil moisture
sensor in lots of different conditions
including dry air potting soil and this
cup of water
apparently what's in this cup is 98%
water by volume which is pretty good
honestly as a civil engineer that would
have been happy with anywhere between 80
and 120 my sunlight sensor is a cheap
and simple photoresistor it's resistance
changes based on intensity of light and
you can put together a simple circuit
which allows the arduino to read this as
an input actually made an attempt to
calibrate the sensor based on the known
brightness of this flashlight i have no
idea if it's even close to correct
button i have the code reporting this
data in lux which is the SI unit for
illuminance finally I got the sensor
which measures both air temperature and
relative humidity this is the only
digital sensor I'm using it's really
easy to use since all the electronics
are on board and the code is already
written so I just end up with nicely
scaled readings problem with a digital
sensor is that my multimeter can't talk
to it so if there's any need for
troubleshooting I don't really have a
lot of options luckily this one worked
just fine for the actual watering of the
garden I've got a cheapo solenoid valve
from Adafruit I built a little circuit
with a transistor which allows the
Arduino to switch the valve on right now
I have the code check the water level
once a day in the evening and switch on
a soaker hose for a set amount of time
if it's below a certain threshold from
what I've read it's actually better for
the plants and herbs especially to have
some cyclical nature to the wetness and
dryness of the soil rather than just
being constantly well watered this
scheme also reduces the duty cycle on
the valve and if a sensor goes bad
there's
a chance of flooding the yard since all
these electronics are going to be
sitting out in the Sun I'm building a
crude version of a Stevenson screen
which is really just a louvered box that
lets weather instruments be out in the
open without exposure to direct sunlight
or rain I'm using the plywood dregs of
my scrap bin so this is LEED Silver
accredited to get the gold I think you
have to use pallet wood and have a
Pinterest account the enclosure goes
together with a tin soffit vent glue and
finished nails a nice coat of white
latex paint will hopefully help reflect
the Sun well it wouldn't be a hobbyist
project without at least one big gob of
electrical tape and some questionable
troubleshooting but I finally got this
thing working I've had it running for
just a few days now and it's actually
working really well the garden is
happily watered with no intervention
from me even though I check on it now
more often than before it had the Gard
Ueno here's a quick look at some of the
data I'm collecting
combining microcontrollers and gardening
is a really popular idea I think that's
because Gardens have very simple inputs
and outputs that are easy to wrap your
head around soil plus water plus light
equals delicious herbs and vegetables
I guess people myself included see a
notoriously simple and relaxed hobby and
can't help but feel compelled to over
complicate it and there's a growing
market of products out there geared
towards quote unquote makers which are
really solutions looking for problems or
at the very least things which we'd like
to try and use but just for the sake of
using them and for me at least the
Arduino probably falls into that
category but just about anyone can
connect the dots between garden needs
water and I am NOT a responsible human
being who is capable of remembering to
water a garden every day and realize hey
I can use technology to overcome my
personal shortcomings and more than that
I can bend technology to my will and
that will feel good to my ego and my
sense of self-worth after all no one's
hobby is to buy an irrigation controller
off the shelf of a hardware store thanks
for watching and let me know what you
think