Final Presentation November 29, 2011

Team MembersDuties:

Real Time Clock

Website 

Kevin Wellman

Electrical Engineering

Electrical Engineering

Electrical Engineering

Electrical Engineering

Reginald Lott

Adam Teague

Matthew Adkins

Duties:

Power Circuit

PCB Design 

Duties:

User Interface

MicroprocessorProgramming 

Duties:

Sensors

PCB Design 

Dr. Winton

Faculty Advisor

OverviewProblemSolutionSystem OverviewConstraints

TechnicalPractical

ImprovementsPCBEnclosureFinal ProductTestingProduction CostReferencesQuestions

ProblemCurrent residential sprinkler systems are inadequate

in the following areas:EfficiencyEase of useCost

Digital Sun S. SenseAdd-on deviceBattery operated (sensors and control unit)$199 MSRP

[1]

Competing Products

Cyber Rain XCIRequires internet accessWeather reports cover general area$499 MSRP

SolutionWater Conserving Sprinkler Control

Periodically monitors moisture content and temperature

Operates on user-defined scheduleRequires no external devices for modifying settingsCosts less than $175

System Overview

Microcontroller

Moisture Sensor

Temperature Sensor

Power Supply

Sprinkler Interface

Real Time Clock

Physical Model

Technical ConstraintsName  

Description

Moisture Sensor Range

The WCSC must be able to sense the volumetric water content of the soil from 20 to 50 percent.

Outputs The WCSC must be able to output 24 V AC at 0.6A .

Display The WCSC display must provide relevant information and options to the user, and it must be readable in well or dimly lit environments.

Technical Constraints (Cont.)Name  

Description

Temperature Sensor Range

The WCSC must sense temperatures from 20 to 50 degrees Fahrenheit.

Voltage The WCSC must operate from a standard 120V wall outlet.

Type Constraint Description

Environmental Durability The device must be able to operate in harsh conditions.

Usability Customer Convenience

The device must be easy to use and change watering schedule.

Improvements From Design 1

RTC from breakout board to through hole mountable components

AC/DC converter resized from 12VDC to 6VDC

Implementation of PCB from Breadboard

PCB

PCB

PCB

Enclosure

NEMA 4 / IP65 Case with Clear

Cover

Dimensions of 7” x 6” x 3”

Final Product

Systems Test Test were conducted on the following components in

this order after the arrival of the PCB:PCBPower supplyMicroprocessorLCDRTCTemperature SensorMoisture SensorsEnclosureEntire System

Temperature Probe Test DataAmbient temp measured using a Fluke 189

temp probe and compared to LM 60 measurements.

Test Preparations Soil Preparation

Bake at 225°F for 24 hours as per manufacturer

recommendations

Sample size of 16oz of dirt for each zone

Test were performed in increments of 3.125 VWC

Moisture Sensor Test Data

Testing of Entire System

Moisture (VWC)

Current Moisture (VWC)

Test 1 Moisture content greater than Moisture SettingTemperature greater than Temperature SettingSprinkler should not operate

Test 2Moisture content less than Moisture SettingTemperature less than Temperature SettingSprinkler should not operate

Test 3Moisture content less than Moisture Setting Temperature greater than Temperature SettingSprinkler should operate

Operation and Testing

Production CostPart # Description Quantity Price per Unit Price per Unit for 100 VG 400 Vegetronix Moisture Sensor 2 29.95 29.95PIC24HJ32GP202-I/SO-ND Microprocessor 1 4.20 2.74LM60CIZ-ND Temperature Sensor 1 0.92 0.62LM2940CT-5.0-ND 5V Regulator 1 1.77 1.28LM2937ET-3.3-ND 3.3V Regulator 1 1.98 1.44F3167TR-ND 1/2A Fuse 1 0.29 0.29EG4788-ND Push Button 1 0.75 0.54MOC3011M-ND Opto-coupler Triac Out 2 0.82 0.45516-1791-1-ND LED 1 0.62 0.34568-3687-ND TRIAC 600V 1A TO-92 2 0.66 0.453310Y-001-103L-ND Potentiometer 10K 1 2.56 1.62CFAH2402A-YYH-JT LCD 1 26.86 9.34BEN-80PCBLK Enclosure 1 24.54 24.5414A-20-24B28-ND 120/24V Transformer 1 15.21 15.21BP5063-5 AC/DC Converter 5V 200mA 1 6.98 4.5359-211 Pushbutton Switches 3 9.01 7.36DS1307+-ND RTC 1 3.81 2.08SER3302-ND Crystal 1 1.44 0.82P2.4KBACT-ND 24 Ohm Resisitor 2 0.09 0.02P91BACT-ND 910 Ohm Resistor 1 0.09 0.02P220KBACT-ND 2.2K Ohm Resistor 3 0.09 0.02P4.3BACT-ND 4.3K Ohm Resistor 1 0.09 0.02P2.2MBACT-ND 2.2M Ohm Resistor 2 0.09 0.02478-5200-1-ND 10pF Capacitor 2 0.5 0.21478-3150-1-ND 0.1uF Capacitor 2 0.5 0.21Custom PCB 1 19.00 11.75

Total Cost of Parts for 1 Unit 203.63 161.94

References:[1] Sprinkler Warehouse. [Online]. Available:

http://www.sprinklerwarehouse.com/Ground-Soil-Moisture-Sensors-s/7666.htm. [Accessed:

January 18, 2011].

[2] Beanworthy. [Online]. Available:

http://homegarden.beanworthy.com/CyberRain-XCI-16Zone-Automated-Sprinkler-Controller/

A/B000ZHTXEC.htm

. [Accessed: January 18, 2011].

[3] “VG400 Moisture Probe” [Online] Available: http://www.vegetronix.com/Products/VG400/.

Any Questions?