final design report project title: wintergarden design report ... project title: wintergarden team...

EEL 4924 Electrical Engineering Design

(Senior Design)

Final Design Report

25 April 2012

Project Title:

WinterGarden

Team Name:

Green Thumbs

Team Members:

Name: Ryan Consolver

Email: [email protected]

Name: Michael Inscho

Email: [email protected]

Project Abstract: Our project consists of building a self-maintaining hydroponic garden. This garden will be a 4’

by 2’ box standing at 6'3”. The garden will incorporate a variety of sensors into its design, monitoring

variables such as temperature, pH, CO2, humidity, water Electrical Conductivity, and light proximity.

The garden will use the touch based proximity sensor to maintain adequate distance between a hanging

light and the plants. The light will be raised and lowered by a motor and wire. Solenoid valves will be

used to adjust carbon dioxide levels, pH levels, maintain water volume and control nutrient

concentration. Microprocessor timers will control light ON/OFF periods as well as fan ON/OFF times.

All the monitoring information will be displayed on a LCD on the outside of the container.

University of Florida EEL 4924—Spring 2012 25-Apr-12 Electrical & Computer Engineering

/20 Design Report: WinterGarden

Table of Contents Project Features ........................................................................................................................................ 4

Analysis of Competitors ........................................................................................................................... 5

Concept/Technology/Project Archetecture Selection ............................................................................ 6

Flow Charts ............................................................................................................................................. 16

Distribution of Labor .............................................................................................................................. 18

User's Manual ......................................................................................................................................... 18

Bill of Materials ...................................................................................................................................... 18

Timeline ................................................................................................................................................... 19

References or Bibliograph: .................................................................................................................... 20

Figures

Lab Box ...................................................................................................................................................... 4

LM335A ..................................................................................................................................................... 5

HTM2500 ................................................................................................................................................... 6

MG811 ........................................................................................................................................................ 7

BRS pH Probe ........................................................................................................................................... 8

A1002 EC Probe ........................................................................................................................................ 9

Solid State Relay ..................................................................................................................................... 11

Solenoid .................................................................................................................................................... 12

12V Motor .............................................................................................................................................. 119

Tables

Labor Distribution .................................................................................................................................. 17

Bill of Materials ....................................................................................................................................... 18

Gantt Chart ............................................................................................................................................. 19

Diagrams

HTM2500 pin-out...................................................................................................................................... 7

MG811 pin-out .......................................................................................................................................... 8

TL082 pin_out ........................................................................................................................................... 9

LT1111 Circuit ........................................................................................................................................ 11

LM7805 pin_out ...................................................................................................................................... 11

IRF640 pin_out....................................................................................................................................... 13

Atmega324P pin_out ............................................................................................................................... 14



Altium Designs

Temperature Sensor ................................................................................................................................. 6

Humidity Sensor ....................................................................................................................................... 7

CO2 Sensor ................................................................................................................................................. 8

pH Sensor ................................................................................................................................................... 9

EC Sensor ................................................................................................................................................ 10

Voltage Regulator ................................................................................................................................... 11

Relay Boards............................................................................................................................................ 12

Solenoid Boards ....................................................................................................................................... 13

Main Board .............................................................................................................................................. 14

Interconnectivity Boards ........................................................................................................................ 15



Project Features/Objectives

Project Features The WinterGarden is intended for people without adequate time to care for their indoor plants. In indoor

gardening, the amount of light, CO2, nutrient concentration, and pH help determine the quality of the

finished product. WinterGarden will detect each parameter and adjust them to desired levels.

The purpose of the project is to design a self-sustaining garden. The plants will be grown

hydroponically. Normally people that grow plants with indoor hydroponics have to look after them

consistently and adjust the pH and light regularly.

To accomplish these things, this project includes:

Sensors for humidity, temperature, proximity, PH, Electrical Conductivity and CO2

Motor to move the light up and down

Solenoid valves to introduce pH UP, pH DOWN, and Nutrient Solutions

Relay controlled fan for the purpose of lowering temperature

Relay controlled CO2 solenoid

Relay controlled water and air pumps

Reed switches to determine water height and Door ajar.

Pull-up resistor Light Cage with ground sensing

Technical Objectives The objective of WinterGarden is to create a garden that can sustain a plant in a highly sutable

environment without much human interaction (people will have to set it up and fill CO2 tanks and liquid

adjustment solution).

The first problem that has to be resolved is power consumption. The lights used in such systems

can reach the upper hundreds of watts. We plan on using a 300 watt replacement florescent bulb.

Also, since this is a garden, we plan on it being wall powered.

Another issue to deal with is integrating all these sensors in the presence of the light. The

temperature of the light may affect some inputs. We plan on placing sensors in such a way to

reduce this effect and using sensors that have a reduced sensitivity to heat.

The garden should be big enough to grow some plants but not to be cumbersome. We were

thinking a 4’ by 2’ by 6’3” space.

The microprocessor will have to use a pulley system with motor driver to raise and lower the

light.

The pH and water content will be controlled by a solenoid valve.

CO2 level and air temperature will all be monitored and adjusted by the appropriate valves and

fan controls.

The water volume and parts per million will be monitored and adjusted as necessary.

Desired levels for pH and light times will adjust according to the plants life cycle. The

microprocessor will have a timer keeping track.



Analysis of Competitive Products

Costs and Competitors The garden is expected to cost around $500. For this design, many expensive things such as reflecting

walls will not be included. Just looking at the lights, box, all sensors and the motor we are looking to at

least $300. All in one grow cabinets with less control can run from $500 on the cheap side to $2000 with

more expensive lights and containers. We will try to make it as cost effective as possible.

Other products similar to ours include Terrasphere, a soil based system.. Superbloom is

hydroponic with a similar system but the light remains stationary. There are also devices called grow

boxes which are just a reflective closed area for people to attach a light and take care of the plants on

their own. Figure 3 shows a similar product.

Figure 1-LabBox, a similar garden



Concept/Technology/Project Architecture

Parts Temperature

LM335 Temperature Sensor

This sensor is easily implemented with a power supply, ground, and resistor.

To test WinterGarden’s temperature sensing capabilities, we will increase the

temperature of our system by switching on the light or placing a power strip of 100W

incandescent light bulbs inside the enclosure. The temperature change will be displayed

on the LCD and if the temperature is above the desired value, a fan will turn on to cool

the system down. We do not anticipate dealing with any temperature that needs to be

adjusted upwards as plants thrive in temperatures as low as 65 degrees Celsius and the

light cycle while provide nominal heat.

Figure 2- LM335A

Altium Design 1- Temperature Sensor



Humidity WinterGarden will test for the correct humidity. We can make the sensor

think that humidity is high by holding our hand over the physical sensor. If an

increase of the actual humidity in the enclosure is required, we will place an electric

water kettle in the enclosure and boil water to create steam.

Figure 3- HTM2500

Diagram 1- HTM2500 Pinout

Altium Design 2- Humidity Sensor



CO2

MG811 C02 Sensor with TL082 op amps

The MG811 has a very small output range and needs the gain for the ADC to be able

to distinguish enough for measurement. It also requires a high impedance amplifier

for accurate operation.

To test WinterGarden’s control of CO2 we will adjust the ambient in two

ways. First, to examine the system’s ability to monitor and maintain an average of

1500ppm we will open the door to the enclosure and allow it to equalize with the

ambient in the demonstration room. We will then shut the door, activating the

microprocessor’s CO2 control. When the microprocessor senses the CO2 is below

1500ppm, it will activate the CO2 solenoid, injecting the system with low pressure

CO2. When the CO2 sensor reads 1500ppm, the solenoid will shut off.

Second, to test the upper limits of our CO2 sensor, we will place dry ice in the

enclosure and observe a massive increase on our LCD output.

Figure 3- MG811

Diagram 2- MG811 Pinout

Altium Design 3- CO2 Sensor



PH BRS PH Probe, with TL082 high impedance op amps

The TL082 serves as a gain and an offset, as PH probes give a

negative to positive voltage.

To test WinterGarden’s pH control, we will introduce pH

UP or pH DOWN into the system and our LCD will display the

pH changing. When the microcontroller detects the need for

change, the proper solenoid valve, controlling pH UP or pH

DOWN, will activate and return the pH to the desired range (5.5 -

6.5).

Figure 4- BRS pH probe

Altium Design 4- pH Sensor

Diagram 3- TL082 Pinout



Electrical Conductivity Model A1002 EC flow through sensor

Takes an input of 12V and ground and gives an output

WinterGarden will maintain adequate nutrient supply in then hydroponic

reservoir. This will be handled in two ways. First, during the refresh cycle non-

balanced water will enter the hydroponic reservoir from the water storage

container. This water will first have its pH balanced within the range of 5.5-6.5,

likely a value of 6. The electrical conductivity should begin at around 300ppm for

plain water and increase after the balancing of the pH. Then, nutrient solution will

be added to the reservoir to increase the electrical conductivity to the desired level

depending on the nutrient solution. Second, this

EC value and the water level in the reservoir will be maintained by further

introduction of water and nutrient solution, as needed, following their uptake by the

growing plants.

Figure 5- A1002

Altium Design 5- EC Sensor



Voltage Regulator

LT1111 and LM7805 Regulators

Used to change voltage from our 12V transformer to 6, 5, and –5.

Diagram 4- LT1111 Circuit

Diagram 5- LM7805 Pinout

Altium Design 6- Voltage Regulator



Solid-State Relays

We will use solid state relays to control our wall power components.

Figure 6- SSR

Altium Design 7-1xRelay

Altium Design 8-4xRelay



Solenoids

For controlling pH, electrical

conductivity, and C02 we will use

solenoid valves.

These will be switched on and off by

IRF640 MOSFETs activated by signals

from the microprocessor.

Figure 7- Solenoid

Diagram 6-IRF640 Pinout

Altium Design 9-2xSolenoid

Altium Design 10-3xSolenoid



12V Motor

The motor we will use is a 1 RPM gear motor. The

purpose is to raise the light if the plant grows high enough

to touch it.

Light Proximity WinterGarden will maintain appropriate distance

between the hanging light and the growing plants. For our

application, the light has low heat dissipation, thus the

minimum distance required is non-contact. To test our

control, we will touch an electrical ground to the cage

around the light so that it detects contact. This could be as

simple as bending a plant branch to the cage or touching

the cage with a finger. When contact is detected, the motor

will activate and raise the light till non-contact is

established. When the contact is removed, the light will

stop. To subsequently lower the light, the manual

overdrive will be required. This will not be a weakness in

the design as plants do not grow down and plant height

can only be lowered by the user. The external manual

overdrive will allow adjustment to any possible height

within the enclosure.

Figure 8- 12V Motor

Diagram 7-Atmega324P Pinout

Altium Design 11-MainBoard



Interconnectivity

Altium Design 11-Mux Board

Altium Design 12-LCD Board

Altium Design 13-Relay Board



Flowcharts & Diagrams

Hardware Flowchart

The block diagram in figure 2 shows the various connections to the microprocessor.

Chart 1-Microprocessor connections

Software Flowchart

Our flowchart can be found below in figure 2. Since our project is mostly about controlling the plants

environment, we activate and deactivate many solenoids and relays in order to provide it. To avoid

constantly checking some sensitive parameters that have to settle, we will be using timers and interrupts

to check up on the values and then change them. Also, the water will have to be refilled after periods of

time that will be set, such as weekly or monthly.



Chart 2-Software Flowchart

Distribution of Labor Since there are so many parts in this project, we plan on separating it into creating circuits for the

various sensors. We plan on working together as much as possible to complete coding and analog

circuitry. Table 2 shows the estimated distribution of labor.

Ryan Consolver Michael Inscho

Research 50 50

PH Sensor Design 50 50

CO2 sensor design 70 30

Humidity and Temperature

Sensor Design

50 50

Nutrient Sensor Design 50 50

LCD Interface 30 70

Solenoid Interface 70 30

Motor Interface 30 70

PCB Soldering/Testing 50 50

Physical construction 50 50

Sensor Boards Altium Design 70 30

Main Board Altium Design 30 70

Light Cage Mechanism 50 50

Debugging 50 50 Table 1-Labor Distribution



User’s Manual

The device has two modes and 4 user inputs. There is a ON/OFF power switch, a Two-

Month/Three-Month cycle switch, a Vegetation Cycle Reset Button, a Flowering Cycle Reset Button

and a Lower Light button. The ON/OFF switch powers the device. The Cycle Switch chooses a total

grow length. The Vegetation/Flowering reset buttons return the cycle count to the beginning of the

pushed cycle. The Lower Light Button lowers the light.

Bill of Materials (BOM)

Parts List



Gantt Chart / Project Schedule

Timeline The Gantt chart in figure 4 shows the project timeline and when we plan on working on different aspects

of the project.

Table 3-Gantt Chart



References or Bibliography Electronic Components Distributor Digikey. http://digikey.com

http://hydroponicgarden.net/hydroponic-grow-cabinets-c-10.html

References

http://mil.ufl.edu/4924/

MG811

http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/MG811Datasheet.pdf

LM335A

http://www.ti.com/lit/ds/symlink/lm335.pdf

HTM2500

http://www1.futureelectronics.com/doc/MEASUREMENT%20SPECIALTIES/HTM2500.pdf

TL082

http://www.ti.com/lit/ds/symlink/tl082.pdf

LM7805

http://www.sparkfun.com/datasheets/Components/LM7805.pdf

LT1111

http://cds.linear.com/docs/Datasheet/1111fd.pdf

IRF640

http://www.vishay.com/docs/91036/91036.pdf

12V Supply

http://products.cui.com/CUI_ETSA190342UD_Datasheet.pdf?fileID=2620

pH Probe

http://www.bulkreefsupply.com/store/products/monitors-controllers/brs-ph-and-orp-probes/brs-brand-

ph-probe.html

EC Probe

http://webpages.charter.net/tdsmeter/manuals/A1002.pdf

Solenoids

http://www.dudadiesel.com/choose_item.php?id=W04010

http://www.dudadiesel.com/choose_item.php?id=W040B10

Water pump

http://www.sunlightsupply.com/p-13149-ecoplus-eco-396-submersible-pump.aspx

Air pump

http://www.sunlightsupply.com/PDF/HeavyDutyPump_Instructions.pdf

Atmega324P

http://www.atmel.com/Images/doc8011.pdf

SN754410_Motor Driver

http://www.ti.com/lit/ds/symlink/sn754410.pdf

Light

http://www.lowes.com/pd_46931-75774-

65TN_?productId=3197521&site=shopLocal&utm_campaign=bazaarvoice&utm_medium=SearchVoice

&utm_source=RatingsAndReviews&utm_content=Default

pH Up/Down

http://generalhydroponics.com/site/index.php/products/maintenance/ph_buffers/ph_up/

http://generalhydroponics.com/site/index.php/products/maintenance/ph_buffers/ph_down/

Nutrients

http://www.hydro-organics.com/home/index.php?productID=702



http://digikey.com/

http://hydroponicgarden.net/hydroponic-grow-cabinets-c-10.html

http://mil.ufl.edu/4924/

http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/MG811Datasheet.pdf

http://www.ti.com/lit/ds/symlink/lm335.pdf

http://www1.futureelectronics.com/doc/MEASUREMENT%20SPECIALTIES/HTM2500.pdf

http://www.ti.com/lit/ds/symlink/tl082.pdf

http://www.sparkfun.com/datasheets/Components/LM7805.pdf

http://cds.linear.com/docs/Datasheet/1111fd.pdf

http://www.vishay.com/docs/91036/91036.pdf

http://products.cui.com/CUI_ETSA190342UD_Datasheet.pdf?fileID=2620

http://www.bulkreefsupply.com/store/products/monitors-controllers/brs-ph-and-orp-probes/brs-brand-ph-probe.html

http://www.bulkreefsupply.com/store/products/monitors-controllers/brs-ph-and-orp-probes/brs-brand-ph-probe.html

http://webpages.charter.net/tdsmeter/manuals/A1002.pdf

http://www.dudadiesel.com/choose_item.php?id=W04010

http://www.dudadiesel.com/choose_item.php?id=W040B10

http://www.sunlightsupply.com/p-13149-ecoplus-eco-396-submersible-pump.aspx

http://www.sunlightsupply.com/PDF/HeavyDutyPump_Instructions.pdf

http://www.atmel.com/Images/doc8011.pdf

http://www.ti.com/lit/ds/symlink/sn754410.pdf

http://www.lowes.com/pd_46931-75774-65TN_?productId=3197521&site=shopLocal&utm_campaign=bazaarvoice&utm_medium=SearchVoice&utm_source=RatingsAndReviews&utm_content=Default



http://generalhydroponics.com/site/index.php/products/maintenance/ph_buffers/ph_up/

http://generalhydroponics.com/site/index.php/products/maintenance/ph_buffers/ph_down/




final design report project title: wintergarden design report ... project title: wintergarden team...

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