First, we'll construct the frame. I'm using steel tubing left over from a previous project,
but there are a lot of other materials that can be used. One side of the frame is built higher than the other so
water will flow through the channels by gravity. The water channels are made from vinyl
downspouts cut to a length of 30 inches. Holes are cut every six inches on center. Since hole saw bits tend to tear vinyl,
run the bit in reverse to get a nice cut. You can also alternate the hole positions every
other channel to create a checkerboard pattern that maximizes space for plants to grow. One inch PVC was used for pumping water
to each channel. Cement a cap to each end and use a tee in the
center with an adapter that will be used to connect a hose to the water pump. Last, drill five holes in the side and
insert rubber grommets to seal the microtubes that will be installed later. Four inch PVC was used for water collection. Cut off a few inches from the end caps to make them
narrower, then cement them to the ends of the pipe. This is done to give a longer length opening. Make a straight cut along the length of
the pipe from end cap to end cap. Make two more cuts along each
end, creating a long flap. Use a heat gun to soften the PVC and open the flap
enough to allow a channel to fit inside the opening. Then drill a hole for the bulkhead adapter. Apply heat to soften the PVC to allow it
to conform to the adapter when it's tightened and make a watertight seal. Install the water collection pipe on the lower end of
the stand and the water inlet pipe on the higher end. Alternate the channels across the stand to create
a checkerboard pattern with the holes. Next, install the water pump to the inlet pipe and
a drainage hose to the water collection pipe. The last step before starting the water flow is to drill
a quarter inch hole in the inlet side of each channel, then install the microtubes from
the grommets to the channels. Now we can fill the reservoir, turn on the pump,
and see if everything is water-tight. We now have a basic functioning hydroponic
system, with adjustments to the water chemistry needing to be manually performed. To automate the system, we'll need a control
panel to interface all our sensors and devices. The sensors I'm installing will be able to measure
air temperature, humidity, vapor pressure deficit, and carbon dioxide, water temperature,
pH, and electrical conductivity, as well as water flow rate, water level,
and power consumption. Since this is a prototype system, the connections
of the control panel are made on bread boards. However, if this were to be put into a production
system, you'll probably want to develop your own circuit boards, solder your connections,
and add protection from water. Next, I'll push connections for an
LCD through the grow tent wall. This will allow me to install an
LCD to display measurements and stats on the outside of the
tent for easier viewing. For measuring power, I'm using a
split transformer that converts the electrical current being consumed by the
system to a voltage. Up to 20 amps can be measured by this
transformer, with a maximum output of 1 volt. This voltage is then converted to a digital
signal by an analog-to-digital converter so we can ultimately determine how much
current has been consumed over time. I chose to sacrifice a small 1 foot extension
cord to get a single wire to clamp, rather than cutting into my power strip. Now, I'll set up the pumping system
for the nutrient and pH solutions. I modeled mounts that will hold a bottle
below each peristaltic pump in Fusion360, then printed them using Cura and Octoprint. For measuring water level, we'll need
to mount a pipe that will enable us to adjust our float sensor to different heights. Next, we'll build a reservoir for our
electrical conductivity, pH, and temperature sensors to measure the water. We want to separate these sensors
from the main reservoir to allow any chemicals that are added sufficient time
to mix before reaching the sensors. To do this, we'll divert a small amount of water from
the main flow to the plants to fill up the reservoir, which will then spill back into the main reservoir. This lid I modeled and 3d printed will hold the probes. We'll need to drill a new hole in our water inlet pipe
and use a rubber grommet to seal the microtube. Installing the flow meter is simple,
if using compression fittings. Just cut the microtube where it looks like a
good fit and press the ends into the fittings. A fan was added near the top of the tent to exhaust
air and to help control temperature and humidity. Now let's build the box that will allow the
Raspberry Pi to control our electrical devices. This will consist of four AC wall outlets that
are individually-controlled by four relays, which can be switched on and off by the Raspberry Pi. We can now connect an AC power cord to the box, connect the Ethernet wire to our control panel,
then plug in the devices we want to control. I also put everything in a battery box
to protect against water. Installing the software is simple. First, flash the Raspbian OS image
file to a micro SD card. You can now insert the SD card and
power of the system for the first time. Installing Mycodo is even easier. Once
logged into a terminal on the Raspberry Pi, execute the install command provided on Github. Let me give you a brief showcase of
Mycodo before I demonstrate it working. For the sake of time, I've already configured everything,
but this is all detailed in the accompanying write-up. Once you log in, you're greeted with the latest
measurements from our sensors and devices. For a more detailed view, we can create custom
dashboards with a number of different widgets available to display data and allow
us to interact with the system. This dashboard displays information about
water measurements, air measurements, flow, and electrical current consumption, as well
as a live stream with the Raspberry Pi camera. Each of our inputs are configured on the
Data page, where you can configure options such as measurement period, which
measurements to record, among others. On the outputs page, we can configure our
four peristaltic pumps and four relays. We can also test our outputs to ensure
they're working before using them in the rest of the system with our automation tasks. Calibration is a crucial task. but can be
tedious. Mycodo makes this easy by providing walk-throughs for the calibration
procedures for several devices, including the peristaltic pumps and pH and
electrical conductivity sensors we're using here. Once we have inputs and outputs
configured and working properly, we can combine them to perform autonomous tasks. The most simple of these are simple timers, which
we're using to turn our lights on from 3 AM to 8 PM. Next we have our most complex function, which monitors and regulates the water
pH and electrical conductivity. This type of function is called a conditional controller and allows different conditions and actions to be
used within Python code created by the user. Here we have two measurements,
our pH and electrical conductivity, with several actions for manipulating
the peristaltic pumps. We essentially have minimum and maximum
allowed values for each measurement. If our measurements fall outside these ranges, peristaltic pumps will dispense small
amounts of solution to bring them back. This function will run every 5 minutes, giving the sensors enough time to adequately
detect the change in water chemistry before checking the measurements again. The next function is a PID controller
that adjusts the vapor pressure deficit to an optimum range with a humidifier and exhaust fan. There are also simple monitor functions
that will send an email to me if certain measurements aren't what they should be. I also have a function to trigger the
remote shutter of my DSLR camera every three hours to create a high-quality time-lapse. And last, there's a simple timer for ensuring the
exhaust fans run periodically to bring in fresh air. We could also create more functions such as
incorporating the CO2 sensor for regulating exhaust, but this is a good set to start with. Let's go ahead and activate our pH and
EC regulation function and see it in action. Since the addition of nutrients will impact pH, the
function will first add nutrients until the water's electrical conductivity rises above
800 microSiemens per centimeter, then either acid or base will be added until
the pH returns between 5.5 and 6.5. I cultured a biocontrol agent to protect from
microbial pathogens and contaminants. This is a bacterium named Streptomyces griseoviridis, commercially known as MycoStop, and will colonize
the whole system, including the plant roots, preventing many harmful microorganisms
from establishing. Now that we have the proper water chemistry
and light schedule, we can plant our seeds. The seeds I'm planning are basil, along with
red and green oak leaf and butter lettuce.
That’s pretty neat. Are you like an electrical engineer or something?
Hats of Man!! Which type of software did you use in RPI? I mean in webbrowser just configure and play!! Awesome.
This is absolutely amazing! This is exactly what I want to put in my new house! Thank you so much for such an informative video about your project.
I just checked out your github for this. Wow, it does more than just grow veggies! Kudos for using Docker too!
What kind of yield do you see with this build, if growing just lettuce?
Gold for the amount of effort that went into designing and documenting. Here’s the write up link for others: https://kylegabriel.com/projects/2020/06/automated-hydroponic-system-build.html
I’m just about to start designing my system. I plan to grow outdoors and in a greenhouse, so not hydroponic. Starting with some moisture sensors and 4 valves to keep them at the right moisture. Need to look into other sensors next and start designing the whole thing. I’m fairly new to gardening but experienced with IoT.
this is so freaking cool. I just stumbled into here. I'm on your site build page, loving it. Thank you kindly. I've opened the amazon links there too, would love to support however I can!
I recently picked up a pi 3+ to monitor a pond in my back yard.
I'd like to set something up to monitor the nitrogen cycle of the pond. Any tips I'm all ears!! I'm still digesting what I would get out of an ORP sensor or conductivity probe. If I'm looking to monitor my nitrogen cycle, I'm not sure if I use stoichiometry through it or not. So many questions!
Starting basic with pH/temp getting pi set up and good to go.
The water 24H flowing will not damage the root's plant?