Design of hydroponic farm based on IoT

A vertical hydroponic garden

Allows for high density production and shorter growing cycles

Reduce resource consumption – water, fertilizer and space

Less labor - no need to till weeds or soil

Greater crop consistency and better taste

Maintained by microcontrollers (RaspberryPi and Arduino)

Watering Cycle - monitors and automatically replenishes water levels

Plant nutrients and pH - monitoring and correction

Temperature monitoring

Air circulation and lighting control (for indoor operation)

Smart connectivity

Farm controller app for smartphones, tablets and PCs

Get notified when your system needs replenishing

Get alerted when something isn't working as expected

Year-round planting - fresh produce every month of the year

Ideal for urban environments where space is limited

Reduce operating time and maintenance through automation

Take the guesswork out of nutrients and watering cycles

Hydroponics, a subset of hydroponics, is a method of growing plants in water, without soil, using a mineral nutrient solution.

The word hydroponics technically means worked water and is derived from the Latin words "hydro" meaning water and "ponos" meaning labor. Many different civilizations have relied on hydroponics to grow plants since the beginning, such as early Mexican and Egyptian civilizations. However, recently hydroponic growing has been gaining popularity and use in many different markets.

Green and efficient

The water is recirculated, which allows for high efficiencies, typically exceeding 90% efficiency of water consumption.

Our vertical design allows for a higher density of plants in a smaller footprint. In a space less than 5'x5' we are growing 160 plants.

automation

The system is maintained by a series of Arduino controllers. Watering cycles, pH levels, nutrient levels, lighting cycles, and ventilation fans are all maintained via the Arduino.

The Arduino can be networked to the RaspberryPi using I2C to allow real-time monitoring and updating of all system parameters. The RaspberryPi is further used to maintain a historical log of all system operating data and make it available through a set of if network services.

The companion smartphone/tablet app connects with the RaspberryPi, allowing configuration and monitoring of your entire system from anywhere in the world. The RaspberryPi communicates with the app via a JSON web service.

What are we growing?

Vertical hydroponics is great for leafy greens. I am currently successfully growing lettuce (romaine, Boston bib, spring mix), cabbage (red and green), herbs (basil, cilantro, mint, dill, chives), spinach, kale (dwarf curly variety), broccoli, and petunias.

Parts and Components

Support frame

(5) 10'-2" PVC pipe

(1) 10'-3" PVC pipe

(4) 2" PVC 90° elbow

(8) 2” PVC Tee

(4) 3" to 2" PVC Tee

(4) 3" PVC end caps

NOTE: All PVC pipe and fittings are Schedule 40 - Cellular PVC

Tower/Return

(10) 10'-2"x3" PVC downspouts

(1) 10' PVC Extruded Gutter 4"

(4) PVC gutter end caps (make sure to have 2 on the left and 2 on the right)

(2) 1" thread to 3/4" barb adapters

(2) 3/4" PVC female connectors

(20) 2" PVC pipe hangers ("J" hooks)

(20) #6 stainless steel 11/2-inch machine screws and nuts

Water supply/return

(1) 10'-1" ID potable water pipe

(3) 1" thread to 3/4" barb adapters

(1) 1" Barb Tee

(5) 3/4" PEX 90° Elbow - Barbed

(1) 3/4" PEXT Shirt - Barb

(1) 1" to 3/4" PEX Reducer - Barbed

(2) 10 PEX crimp rings

(1) 10-pack 11/2" hose clamps

(1) 25'-3/4" PEX

(20) Adjustable 0-10GPH drip irrigation device

(1) 14-gallon soft plastic bucket

Support frame (see pictures for steps)

The support frame is made from standard wall thickness 40PVC in 2" and 3" OD (outside diameter). The frames are made from this material for their modular nature (easy to fit together) and accessible sizes (straightforward to cut with basic tools). This does not preclude the use of other structural materials such as wood, plastic and metal as the frames are structural and do not carry water.

Tool Description:

The PVC pipe for this project is best cut using a miter saw. They are easily available as an inexpensive hand tool or electric/powered tool. A miter saw provides a nice 90° cut and helps add stability to the frame.

PVC is glued using a two part glue system.

Oscillating multi-purpose power tool for cutting grooves in vertical towers.

Use a heat gun to shape the pockets in the vertical tower.

The support frame is (2) main leg assemblies connected by (2) "top bar" assemblies and (2) "cross braces".

The length of the "top bar" and "cross bracing" determines the capacity of the tower your system will support.

There are two additional leg extensions made from 3" PVC to provide additional support from the elements when used outdoors. These can be omitted for indoor use.

At 4' we support (10) grow towers spaced 4.5" apart on center.

Support top

Top supports determine the size of your growing system and the number of towers the system can support.

Our current plans include a 4-foot length of 2" PVC with towers spaced 4.5" on center. The spacing can be modified to support a larger growing area by increasing the spacing between tower centers.

Additionally, you can reduce the length of the pipe to support a smaller number of grow towers.

The supporting top structure is (2) identically constructed units.

Support for top-level cut lists

2" PVC from 10' section

Cut (2) sections at 48" - (these are Section 1 - Set 1 and 2)

Support top assembly instructions

Dry pack as follows:

Install 2" pipe part #1 into (2) part #2 90° elbow

Support bottom

As with the top brace, the bottom cross determines the size of the system and this piece must be the same width as the top of the bracing frame.

Our current plans include 4-ft. lengths.

The support bottom is (2) identical 4' sections.

The bottom of the frame also includes (2) optional extension legs which are great for providing additional wind support when mounting the unit outdoors.

Support bottom cut list

2" PVC from 10' sections

Cut (2) sections at 48" - (these are Section 1 - Set 1 and 2)

From the remaining part of the 3" PVC

Cut (4) sections at 12" - (these are section 2)

Support up and down commands

Dry pack as follows:

Install 2" pipe part #1 into part #6 90° tee of main leg assembly

NOTE: When installing the bottom crossbar, you will need an extra person to help support the legs

Optional: Install 3" pipe part #2 to part #990° tee on main leg assembly

Optional: Install Cap Part #3 to 3" Pipe Part #2

Planting tower/return water

The towers provide growing areas for the plants in this system.

Or the current design supports very high density plants by spacing 3" vertical growing towers 4.5" on center (distance from center of tower to adjacent tower), providing approximately 1.5" between towers.

The current 4' length supports (10) towers, each with (8) slots. With both sides we get (160) plants for our total system.

This high-density and vertical growing system has some limitations on the types of plants you can grow.

Tower/Return Overview

The towers are 2"x3" PVC modified downspouts. Downspouts typically come in 10 foot sections.

The availability of 10' sections dictated the 5' height of our design.

The returns are 4" PVC rain gutters. Also available in 10' sections. They are cut and capped on the ends with gutter caps. Make sure you pick up the left and right version of the end caps as they are different.

Tower/Return Construction Steps

Part 1: Tower

Pyramid Cutting List

From a 10 foot length of 2"x3" PVC downspout

Cut (10) sections in half at 60 inches

Tower Forming Instructions

We built a wooden template tool to help form the plant pockets.

Divide the (20) towers into (2) groups of (10).

To improve the growing space, we offset/stagger the plant slots in the growing towers.

Mark a horizontal line in front of the first set of (10) towers, every 6" from the bottom for (8) lines.

Speed ​​squares are helpful and can create a straight line through the downspout material.

Mark a horizontal line in front of the first set of (10) towers, starting every 6" and 9" from the bottom for (8) lines.

Using an oscillating multi-purpose power tool with a straight-cut drill bit, cut 2" slices on the drawn lines.

Use a heat gun to soften the plastic 3 inches above and 3 inches below the cut for a few seconds (about 15-30 seconds, depending on the wattage of the heat gun). The PVC will begin to wrinkle or sink and take on the appearance of wet, saggy paper.

Use your wooden template to slide in the softened PVC at the cutout. Hold in place for about 30 seconds.

Repeat this for the remaining slots in the tower.

Drill 3/16" holes in the top and back of the tower to accommodate the screws for the tower hanger.

Return water

Backwater Cutting List

From 10 feet of 4" PVC gutter

Cut (4) sections at 46"

Return Water Assembly Instructions

Identify the left and right gutter end caps.

Test the end caps installed on the gutter sections.

We used some 150 grit sandpaper to rough-sand the gutter plastic where the cap overlaps the gutter (about 5/8") for better adhesion.

Apply a generous amount of silicone PVC adhesive to the inside overlapping edges of the end caps.

Carefully install the end cap onto the gutter, making sure the glue contacts all around the gutter material.

We used our fingers to push any excess adhesive around the edges of the gutter and cover to ensure good contact.

Place a piece of masking tape or other easily removable tape on the cover until the recommended drying time is reached.

Repeat with the other 3 sides and set aside until dry.

Drill a 1" hole in the back wall of the 4" gutter to insert the 1" to 3/4" barbed adapter. This will serve as the connector for the return to the 14 gallon bucket.

Thread the 1" threaded side of the adapter into the 1" female connector on the inside of the gutter.

Cut (2) -12" sections of soft 1" vinyl hose for each side of the water return.

Use a 1" barbed tee to attach in the center.

Cut a length of vinyl tubing to the appropriate length for your 14-gallon tank.

Water supply

We chose 3/4" PEX for the main water supply line because of its drinking water safety features and ease of installation since we had a PEX crimp installation tool. If you don't have a crimp tool, CPVC is also a good choice. CPVC is also certified for drinking water but requires glue and union connectors for assembly.

Supply/Return Overview

The water source is arranged so that there is a single rise at the center beam of the main leg. This design was implemented to reduce the overall height load on the water pump. Unlike (2) the 6' rise which reduces the total water flow, the rise is slightly more efficient for the pump.

Water supply/return construction steps

Parts #1-#6 are 3/4" PEX cut to reflect the main leg dimensions.

These are the best sizes to determine by measuring your leg size.

Crimp Part #1, Part #2 and Part #3 and Part #7 - 3/4" PEXT Shirt with Barb.

Crimp Part #3 and Part #4 together with Part #8-3/4" PEX 90° Elbow.

Crimp Part #4 and Part #5 together with Part #9-3/4" PEX 90° Elbow.

Crimp Part #2 and Part #6 together with Part #10-3/4" PEX 90° Elbow.

Drill holes in Part #5 and Part #6 for Part #11 - Drip Irrigator.

Starting at the end of the elbow on Part #5/Part #6 - measure 4" from the end and mark the first hole on the bottom of the PEX pipe.

It is helpful to draw a line along the bottom of the PEX pipe to mark the bottom of the remaining markings.

Measure 4.5" from the first mark and make the second mark.

Repeat every 4.5 inches, and the last mark should be 4 inches from your elbow to your other leg.

Use a 3/16 drill bit on the marks.

Installation in drip irrigation - Part 11

The holes of the dripper are slightly snug to prevent unwanted dripping, and the PEX is softened briefly (30 seconds) with a heat gun, this will make it easier to insert the dripper into the PEX.

Cut a 1-inch hole in a 14-gallon bucket.

Thread the 1" to 3/4" barbed adapter through the water container wall.

Connect a soft vinyl hose from the sink return tee to the bucket.

Electronics

We decompose the functionality of the controller into separate components.

Climate Robots

Function: Environmental control for indoor operations.

Used to maintain light cycles according to an on/off interval schedule and thermostatic and/or schedule-based control of circulating fans.

Hardware Components

(1) Arduino

(1) Arduino 2-channel relay module board and expansion board

(1) A circulation fan that is appropriate for the size of your space

(1) 15m - LED based - 12v flexible 50505:1 red/blue

(1) Waterproof DS18B20 Digital Temperature Sensor Probe for Arduino

robot

Function: Water quality control

Used to maintain pH level maintenance and nutrient level maintenance.

Hardware Components

(1) Arduino

(1) Arduino 2-channel relay module board and expansion board

(1) Analog pH meter kit

(1) Arduino conductivity sensor

(1) Waterproof DS18B20 Digital Temperature Sensor Probe for Arduino

(2) 12VDC peristaltic metering pump

Hydropower Robot

Purpose: Watering cycles based on on/off time intervals and reservoir level maintenance schedules

(1) Arduino

(1) Arduino 2-channel relay module board and expansion board

(2) Side mounted water level control float switch normally closed

(1) 1" water flow meter counter 1-60L/min

(1) 1/2" DC12V electric solenoid valve water inlet flow switch normally closed

(1) 620GPH submersible pump