Calvin College Senior Design Team 11Aaron Maley Jeff OverwegSimeon Eisen Jacob VanderWall

THE TEAM Simeon Eisen Jeff Overweg Aaron Maley Jacob VanderWall

A NICHE IN THE MARKET There are current pool care systems,

but they are not created and marketed to the average residential pool owner.

Current systems range in price from $1200-$7000 for just the controller alone

A product with the features of the high end systems, at a price that residential pool owners can afford would be a very viable real world product

THE PROJECT To create an affordable chemical control

system for the residential pool market.

What Does it Do? Sample pool water at regular intervals

Microprocessor controlled system Dispense chemicals into the pool pump system

Granule feed system Broadcast pool data via website

Wireless module

MICROCONTROLLER SYSTEM Goal:

Use an embedded microcontroller to control water testing, chemical dispersal, local display, and data being sent to web server.

Major Components and Interfaces: Sensors and Related Circuits Chemical Dispersal Control Local Display/User Interface Analog Data to Web Server

MICROCONTROLLER SYSTEM Full System

Diagram

MICROCONTROLLER SYSTEM Sensors and Related Circuits

Three main sensor inputs Temp, pH, ORP

How are the amounts of Chemicals Needed Calculated? pH, ORP, temperature readings and size of pool

are used to calculate the required dosage Dosage precision can exceed 0.25 oz

FREE CHLORINE CALCULATION

550 600 650 700 750 800 850 9000

1

2

3

4

5

6

7

8

9

10f(x) = 1.4818570105462E-42 x^14.878438602951R² = 0.999134032453171

f(x) = 3.45301367750078E-58 x^20.0989712494528R² = 0.998415565197075f(x) = 3.32883049618107E-69 x^23.734034345008

R² = 0.999538310985709f(x) = 1.11089362419315E-82 x^28.2095631061152R² = 0.998221894253147

f(x) = 2.96330528734171E-103 x^35.0724486795012R² = 0.997884032039689

Free Chlorine as a Function of pH and ORP6.5

Power (6.5)

7

Power (7)

7.5

Power (7.5)

8

Power (8)

8.5

Power (8.5)

ORP (mV)

Free

Chl

orin

e (p

pm)

MICROCONTROLLER SYSTEM Local Display/User Interface

Graphic LCD Touch Screen Interface

What does this allow the user to do? Directly view relevant information Calibrate probes and sensors Define parameters such as:

Pool Volume Pump Cycle Time

MICROCONTROLLER SYSTEM Data to Web Server

Analog Level Created with: PWM signals passed through a low pass filter

How does the Web Server Interpret Values? Varying Duty Cycles Form Different Voltage

Levels Communication Specification for Analog

Interpretation Defines Relationships

MICROCONTROLLER SYSTEM Chemical Dispersal Control

Digital Control Logic (Stepper Motor Control) Solenoid Valve Channel Control

How the System Disperses the Chemicals

INSTRUMENTATION SETUP Sensor Chamber Design

DISPENSER Goal:

To create an interface that would utilize the existing pool pump and filter system to dispense and mix chemicals into the pool water.

Two distinct elements Auger Based Dispenser Diverted Mixing Chamber

MECHANICAL SETUP Final Mechanical Implementation

Pool

FilterPumpSensor ChamberDispenser

MECHANICAL SETUP Dispenser System Design

MECHANICAL SETUP Dispenser Prototype

WORKING COMPONENTS

DISPENSING CALIBRATION

0 5 10 15 20 25 30 35 40 45 500

100

200

300

400

500

600

700

800

900

1000

f(x) = 19.5622497998399 xR² = 0.999998095952494

Dispenser Output Mass vs. Auger Rotation

Mass (g)Linear (Mass (g))

Rotations

Out

put

Mas

s (g

ram

s)

STEPPER MOTOR AND SOLENOID CONTROL

WIRELESS WEB SERVER Goal:

To create a basic web server in order to wirelessly broadcast system readings to the consumer.

Main Components 802.11b Chip/Security Settings Analog Input/Calculations Website Design

WIRELESS WEB SERVER 802.11b Chip/Security Settings

Chip/Development Board Selection Arduino Development Kit Wishield

Security Capabilities Compatible with modern 802.11b/g routers Can utilize 64bit WEP, WPA, WPA2 encryption

WIRELESS WEB SERVER Analog Input Calculations

Varying Duty Cycles + Low Pass Filter Analog Voltage 0V – 5V Communication Specification Determines pH,

ORP, Chemical Status, Temperature

Calculation of Free ChlorinePWM

+0-5 Volts Analog

Low-Pass Filter

WIRELESS WEB SERVER Page Design

WIRELESS WEB SERVER System Block Diagram

COMPETITIVE ANALYSIS Main Competitors:

Chemtrol CAT Aquasol

Competitor’s System

Features Price

Chemtrol 250 pH and ORP Controller $1995.00CAT 4000 pH and ORP Controller + Web

Monitoring$3650.00

Aquasol SPC Controller

pH and ORP Controller $2130.00

Chemtrol PC2000 pH, free Chlorine, Remote interface

$3150.00

SALES & MARKETING Customer Base

Existing( US alone) 5.1 million in-ground pools 3.7 million above-ground pools

Growth( Based on 2007) 131,000 new in-ground pools 233,000 new above-ground pools

Target Demographic Work with BUS 397 Advanced Marketing Class Middle-aged to Elderly in Average Middle to

Upper Middle Class Homes

GOING BEYOND Different ways project could be enhanced or

developed further. Expand Wireless Capability and Complexity Add Online Data Logging Add Wireless System Control Use Precision Designed Mechanical Parts Integrate onto single PCB Develop Business Plan as a Distributer and/or a

Supplier

ACKNOWLEDGEMENTS Tim Theriault– Industrial Consultant Prof. VanderLeest – Team Advisor Brian Honeck, Eric Walstra, Darryl DeBruin – CEAC

Reviewers Bob DeKraker – Parts Ordering Phil Jasperse – Shop Help

QUESTIONS