design report.doc
TRANSCRIPT
The Coin-Operated Washer/Dryer Control System
End-Product Design ReportMay 04-05
CLIENTGeorge Ensley
FACULTY ADVISORSNicola Elia
Ratnesh Kumar
TEAM MEMBERSGreg Herr
Craig Zamzow Latrice Baggett
Hisham Chowdhury
DATEDecember 17, 2003
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TABLE OF CONTENTS
LIST OF FIGURES……………………………………………………………….. iii
LIST OF TABLES………………………………………………………………… iv
LIST OF DEFINITIONS………………………………………………………….. v
1.0 ABSTRACT…………………………………………………………………… 1
1.1 Acknowledgements..…………………………………………………... 1
2.0 PROBLEM STATEMENT
2.1 General Problem Statement…………………………………………… 2
2.2 General Solution Approach………………………………...…………. 2
2.3 Operating Environment………………………………………………... 3
2.4 Intended User(s) and Use(s).…………………………………………... 3
2.5 Assumptions and Limitations…………………………………………. 4
2.6 End-Product Description and Other Deliverables…………...………... 5
3.0 APPROACH AND DESIGN
3.1 Design Objectives……………………………………………………… 6
3.2 Functional Requirements……………………………………………… 7
3.3 Design Constraints…………………………………………………….. 9
3.4 Technology Considerations…………………………………………… 10
3.5 Testing Description……………………………………………………. 11
3.6 Recommendations Regarding the Project Continuation………………. 12
3.7 Detailed Design……..…………………………………………………. 13
3.7.1 Component Interface Diagram………..……………………... 13
3.7.2 State Machine Diagram……………………………………… 15
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3.7.3 Typical Work Scenarios by the Coin Operated Washer/Dryer Unit 18
3.7.4 Estimated Component Costs………………………………… 18
4.0 RESOURCES AND SCHEDULES
4.1 Personal Effort Budget..……………………….………...…………….. 19
4.2 Other Resources……………………………………………………….. 20
4.3 Financial Budget………………………………..……………………... 20
4.4 Project Schedule and Deliverables……..……………………………… 21
5.0 PROJECT TEAM INFORMATION...………………………………...………. 23
6.0 SUMMARY…...………………………………………………………………. 25
7.0 REFERENCES………………………………………………………………… 26
8.0 APPENDIX A…………………………………………………………………. A-1
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LIST OF FIGURES
Vertical Eight Coin Mechanism…………………………………………………... 4
Interface Diagram…………………………………………………………………. 14
State Machine Diagram…………………………………………………………… 17
Project Schedule Fall Term……………………………………………………...... 21
Project Schedule Spring Term…………………………………………………….. 21
Project Deliverables Fall Term……………………………………………………. 22
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LIST OF TABLES
The Design Objectives…………………………………………………………….. 6
The Functional Requirements……………………………………………………... 7
The Design Constraints……………………………………………………………. 9
The Technologies Considered……………………………………………………... 10
Table of Components……………………………………………………………… 13
Table of States……………………………………………………………………... 16
Estimated Prices…………………………………………………………………… 18
Personal Effort Budget…………………………………………………………….. 19
Additional Resources…………………………………………………………….... 20
Financial Budget…………………………………………………………………... 20
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LIST OF DEFINITIONS
Owner – the owner or manager of a laundromat
Customer – a person paying for use of a washer or dryer
PIC – programmable interrupt controller, micro-controller
LCD – small monochrome display unit
12 button keypad – numeric keypad, input device
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1.0 Abstract
The cost and proprietary mechanisms of commercial coin-operated washer/dryers are
limiting the potential of laundromat businesses. The team’s client, George Ensley, has
envisioned a separate coin unit to allow the use of non-commercial washer/dryers in his
laundromat business. The team’s approach is to develop a separate, coin-operated unit
that is independent from the washer/dryer that it controls. The use of non-commercial
washer/dryers will allow laundromat owners to have lower initial costs and higher resale
values for their washers and dryers.
1.1 Acknowledgements
The team would like to acknowledge the work of the phase 1 and the previous phase 2
groups. The Team would also like to thank George Ensley for his help.
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2.0 Problem Statement
The general problem statement, general solution approach, operating environment,
intended user(s), intended use(s), assumptions, limitations, and end-product description is
outlined in the following sections.
2.1 General Problem Statement
The Coin-Operated Washer/Dryer Control System must be relatively inexpensive and the
internal logic must be designed to recognize and control various situations which may
arise while using a non-commercial washer/dryer. These problems include the
unbalancing of a top loading washer, the recognition of an idle dryer; recognize an open
door on a washer, recognizing the end of a cycle for a washer and dryer, and detection of
coin payment.
2.2 General Solution Approach
The Coin-Operated Control Systems design will use timers and an inductive current
sensor circuit to recognize idle machines and the end of a cycle. The occurrence of an
unbalancing will be detected by the measurement of a high voltage signal from the
unbalancing sensor on the washer. This voltage signal will be wired from the machine’s
unbalancing sensor to the Coin Operated Washer/Dryer Control System. A mechanical
relay will be used to detect the coin payment. When a customer inserts coins into the
slotted coin device and pushes the handle of the coin mechanism, the relay will send a
signal to the microcontroller, recognizing the payment.
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2.3 Operating Environment
The Coin-Operated Washer/Dryer Control System will be placed inside a heated and air-
conditioned laundry facility. The temperature will not vary greatly, but the machine may
be placed near the potentially drafty escape duct of the dryer. The system should be able
to operate from forty degrees Fahrenheit to one hundred twenty degrees Fahrenheit.
Since the machine is going to be near a washing machine, it should be watertight in case
of broken pipes or other accidents that might cause water to build up around the machine.
The casing should also be able to withstand a moderate amount of abuse since it will be
touched and used on a daily basis.
2.4 Intended User(s) and Use(s)
Primary users of the Coin-Operated Washer/Dryer Control System will be laundry
facility customers who will pay for the use of laundry machines, and laundry facility
owners/operators. The laundry facility customers will have basic interactions with the
device, such as coin payment and starting and stopping the washer/dryer. The laundry
facility owners/operators will have administrative privileges such as setting cycle timers,
setting cost per load, and reading and resetting the number of cycles per machine. In
addition to these settings, the laundry facility owners can set the open door window time,
which is the time allowed for a customer to open the machine door and restart the
machine before the system resets.
This product is ideal for people who own laundry facilities with multiple machines. This
product allows them to monitor a machine’s usage. This will allow them to strategically
move machines according to their usage, which will in turn allow for more uniform wear
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on all of the machines. This product has potential in other markets as well; other uses for
the device may include: pay-by-hour televisions in a public setting, coin-operated tanning
salons and coin-operated computers/internet.
2.5 Assumptions and Limitations
Assumptions and limitations of the coin-operated washer/dryer unit is outlined in the next
two sections.
2.5.1 Assumptions
The team’s assumptions for the coin-operated washer/dryer unit.
The current through the washer or dryer is considerably less when the machine’s
door is open compared to during normal operation, possible zero.
The temperature in the laundry facility will always be between 40º F and 120º
Fahrenheit.
The coin mechanism only takes quarters as the coin payment.
The current though the washer is considerably less when the machine is done.
Washers used with the device will have a door relay indicating that the door is
open.
The non-commercial washers will stall under
the unbalancing condition.
Dryers used in the laundry facility will have a
start button or knob; they will not automatically Figure 2
start when the door is closed.
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Washers used in the laundry facility will contain no more than 3 variable-timed
cycles. For example: whites, bright colors, colors.
2.5.2 Limitations
Prototype must cost less than $150.
The machines require a 240V or 120V outlet.
The unit has the possibility to be subjected to theft and vandalism.
Washers used in the laundry facility will contain no more than 3 variable-timed
cycles. For example: whites, bright colors, and colors.
The wire connections between the washer/dryer and the coin-operated control
system must be able to be easily disconnected by owner only. Otherwise users
can bypass coin-operated control system.
2.6 End-Product Description and Other Deliverables
The final product will be a fully functional coin operated control system that will regulate
power flow to non-commercial washers and dryers. The end-of-project deliverables
include the final prototype, the PIC code, wiring schematics, the prototype budget, copies
of all senior design course documents, and a brief user’s manual.
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3.0 Approach and Design
The approach and design of the coin-operated control system is broken into the following
sections; design objectives, functional requirements, design constraints, technology
considerations, testing description, project continuation, and detailed design.
3.1 Design Objectives
The objectives in Table 1 list the technical challenges that need to be met in the coin-
operated washer/dryer unit.
Table 1: The Design ObjectivesObjective Brief DescriptionRecognize an idle dryer. Recognizing an idle dryer will allow the coin operated
unit to reset itself in the situation where a dryer was only used for a partial amount of the total allotted time. A circuit, using an inductor, will measure current usage by the dryer. This current measurement will be an input into the micro-controller.
Recognizing the end of a cycle for a washer and dryer.
Timers and inductive measuring circuits will recognize the end of a cycle within a washer or dryer. At the end of a cycle, the cycle count will be incremented and power to the machine will be turned off. The known length of a wash/dry cycle is a variable in the micro-controller that will distinguish between user interruption and cycle completion.
Detection of coin payment. The detection of payment is done through a coin mechanism; when coins are inserted into the slots and the mechanism is pushed inwards a relay will be switched. The micro-controller will sense this relay and begin its initialization and monitoring processes.
Recognize an open door on a washer.
The detection of current drop during a known wash/dry cycle will initiate a timer. The micro-controller will pause or extend the timers as needed to allow the washer to complete its cycle.
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3.2 Functional Requirements
The functional requirements in Table 2 describe the end product’s functionality.
Table 2: The Functional RequirementsRequirement Brief DescriptionThe cost per cycle shall be varied by the owner of the laundry facility.
Different markets will allow for different prices in laundry machine usage. By using a variable cost the control unit will be applicable to all markets which use U.S. currency.
The unit shall cut power from the washer/dryer when the overall timer expires and indicate to the customer that the cycle has ended.
The control unit will regulate the maximum amount of time the machine may run for each payment. When the control unit detects that the machine has finished its cycle or total allotted time, a light or sound will be transmitted to the laundry customer to indicate the end of the cycle.
The unit shall power on when the customer enters in the correct amount of currency.
The control unit will remain in a standby/ready state until a form of payment is detected. At that time the control unit will allow power to the machine and monitor the machine.
The unit shall accept quarters as payment.
The coin mechanism will accept up to 8 quarters as a form of payment.
The unit shall display the total remaining time during the washing/drying process on the LCD display.
This time will be displayed in units of minutes. The unit of “min” will also be displayed.
The unit shall contain a 120V and a 240V plug-in socket for the washer/dryer.
Most washers use a 120V outlet and most dryers use a 240V outlet. Either machine may be connected via either socket.
The unit shall provide a locking mechanism that will secure power cord of washer/dryer and the coin mechanism to the wall
This measure is taken to prevent laundry customers from unplugging a machine and plugging it into another local outlet.
The unit shall be Underwriters Laboratories, Inc. (UL) approved.
This is a safety precaution. The laundry facility owners will have access to the inside of the control unit; all connections must prevent the owner/user from incurring shock.
The unit shall keep records of the washer’s/dryer’s cycles.
The control unit will count cycles. The owner will have the access to view cycle counts and reset cycle counts. The owner will interface with the control unit by a 12-button keypad.
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The unit shall enter a standby mode when machine is not in use.
In this standby mode the LCD will display the cost of a cycle. In the standby mode, the micro-controller will be idle until a form of payment is detected.
The unit shall allow a variable amount of time for customers to open and close the washer/dryer doors, after which the unit will reset.
Laundry customers may need to add or remove articles of clothing from machines during a cycle. This window of time will be displayed on the LCD in terms of minutes and seconds. At the end of this window the unit will reset; this allows us to reclaim time when a user is done using the machine. For example: if 20 minutes were used on a dryer which was allotted a total of 60 minutes.
The unit shall control only one laundry machine at any time.
Even though the team has two sockets within the control unit, the design is set up to only monitor and control one laundry machine.
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3.3 Design Constraints
The design constraints will consist of cost, safety, case construction and parts availability.
The design constraints that are considered throughout the design and implementation
process are listed in Table 3.
Table 3: The Design ConstraintsConstraints Brief DescriptionCost constraints: A prototype unit with a maximum cost of $150. This will allow
laundry facility owners a low investment cost and higher return on investment. This will also allow George Ensley to produce a product with a cost-competitive advantage.
Safety constraints: A secured plug-in mechanism. The plug-in cord will be securely fastened to the control unit’s chassis so it cannot be removed by laundry facility customers.
Case construction constraints:
The case should be watertight to prevent water from shorting out the electrical connections or ruining the LCD/PIC.
Part availability constraints:
The PIC, LCD, power supply, relay, and coin mechanism should be readily available parts with a minimal chance of being discontinued by their manufacturers/suppliers.
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3.4 Technology Considerations
The technologies that the team considered are listed in Table 4.
Table 4: The Technology ConsiderationsProject
ComponentTechnologies Considered
Advantage Disadvantage Selected
Current sensing circuit
Inductor Inexpensive Less accurate than AC voltage circuit.
X
Solid state AC voltage circuit
More accurate More expensive than inductor.
Coin Payment Variable coin receptor – a device that allows for multiple units of currency.
Variable cost per load. Some laundry facility owners prefer this.Not very durable.
Need for coin return.
Slotted coin mechanism – a device that accepts quarters.
Set cost per load. Some laundry members like to round the cost per load up to the next quarter.More durable. Mechanically sound.
Slightly more expensive than the variable coin receptor.
X
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3.5 Testing Description
The testing process will consists of three parts:
1. Module testing
Module tests:
A. Micro-controller interface with LCD.
B. Micro-controller interface with 12-button keypad.
C. Micro-controller interface with inductor.
D. Micro-controller interface with 120/240 relay.
E. Coin mechanism interface with micro-controller.
F. Internal micro-code testing - administrative input/output.
G. Internal micro-code testing - regular customer outputs,
such as time and cost.
Testing criteria: Testing results will be labeled as either pass or fail.
Tester(s): The module testing will be evenly distributed to members of the
team.
Verification: All module tests will be verified by another team member.
2. Integration testing
Integration test: The integration test will simultaneously test the interfaces of
the LCD, 12-button keypad, inductor, 120/240V relay, and micro-controller.
Testing criteria: Testing results will be labeled as either pass or fail.
Tester(s): All team members will participate in this test.
Verification: All team members will verify all aspects of the integration test.
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3. Control unit functionality test.
Functionality test: This test will test simulate the two users; the laundry
facility customers and the laundry facility owners. The test will be performed
on the final prototype.
Testing criteria: Testing results will be labeled as either pass or fail.
Tester(s): All team members will assist with this testing. The client will assist
with this testing. Non-technical associates or friends will participate in this
testing.
Verification: The testing will be verified by all team members, the client and
the team’s non-technical associates.
A testing form is included in Appendix A. This form will help the team track the tests
with their results.
3.6 Recommendations Regarding the Project Continuation
At this time, the team will continue with the project as originally envisioned. The team
would like to be further along with the project and will continue to work on the project
over the holiday break between the fall and spring semesters.
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3.7 Detailed Design
3.7.1 Component Interface Diagram
A component interface diagram shows an overall picture of how the many components of
the team’s unit will interface with each other. For a more detailed description on each
component please see Table 5 the Table of Components. Figure 3 shows the interface
diagram.
Table 5: The Table of Components.Component Brief DescriptionLCD Display A liquid crystal display that can display all numbers and letters of
the alphabet.Coin Mechanism This mechanical device accepts up to 8 US or Canadian quarters.
To deposit the quarters the user will push a bar into the device. This will be used in both washer and dryer units.
12-Button Keypad This keypad includes numbers 0-9, ‘*’, and ‘#’.
Inductor This is a simple wire wrapped in a coil. The power cords to the laundry machine are routed through the coil; current through the power cords will induce an alternating current in the current transformer.
Micro-controller The micro-controller is a PIC16F877. The controller has inputs and outputs and can be programmed with the C programming language.
Low voltage power supply
This power supply powers all the low-voltage devices such as the micro-controller, LCD and keypad.
120V socket This is the 3 prong electrical socket commonly found in most houses.
240V socket This is a 3-prong or 4-prong electrical socket most commonly found in a utility room. 240 volts is achieved by offsetting two 120v sources.
120V/240V relay This relay allows power to flow to the laundry machine.
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120V Socket
240V Socket (3-prong)
Figure 3: The Interface Diagram.
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3.7.2 State Machine Diagram
The internal logic of the micro-controller can easily be viewed using a state machine
diagram. Figure 4 shows the state machine for the micro-controller. Notice that the
states have been placed inside boxes to designate the user which will use these cases.
The customer uses the cycle timer state, the door timer state, and the cycle done state.
The owner uses the maintenance mode state, the change door timer state, the change
cycle timer state, the read cycle count state, and the reset cycle count state. Both the
customer and the user will encounter the machine during the idle state. For more
information on the specific states, please see Table 6 the table of states.
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Table 6: The Table of StatesState Brief DescriptionIdle During this state the unit is waiting for some input either from the
customer or the owner. The customer would put money in the machine and the owner will press buttons on the 12-digit keypad.
Cycle Timer During this state the cycle timer is counting down; this timer will be interrupted when the machine’s door is detected to be open. If the cycle timer expires, then the machine was used for the maximum allotted time. The cycle is considered done, and the unit goes to the cycle done state.
Door Timer During this state the door has been opened and the door timer is counting down. If the machine is restarted the unit goes back to the cycle timer state. If the door timer expires, the cycle is considered done and the unit goes to the cycle done state.
Cycle Done During this state, a light is turned on indicating that the machine is done, and then the cycle count is incremented by one. After this, the unit goes to the idle state.
Maintenance Mode
To enter this state the owner must press a specified code on the keypad (which will not be available to regular laundry customers). Once inside the maintenance menu, the owner will have the ability to change, read, or reset the timers or counts.
Change Door Timer
In this state, the door timer value is changed.
Change Cycle Timer
In this state, the cycle timer value is changed.
Read Cycle Count
In this state, the cycle count value is displayed.
Reset Cycle Count
In this state, the cycle count is reset to zero.
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Idle
LCD = Price
CycleTimer
DoorTimer
LCD = Cycle Timer
LCD = Door Timer
CycleDone
LCD = DoneCycle count = cycle count + 1Light = ON
Maintenance Mode
LCD = Maintenance Menu
Change Door Timer
Change CycleTimer
ReadCycleCount
Reset CycleCount
Laundry Facility Customer
Laundry Facility Owner
Figure 4: The State Machine Diagram.
The components used to detect state events are; Door relay switch to detect a door opening. A current transformer to detect the current drop by the washer.
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3.7.3 Typical Work Scenarios by the Coin Operated Washer/Dryer Unit:
The following scenarios will help give an idea of the course of action the control unit will
take throughout common scenarios while a customer does his or her laundry or an owner
modifies the control unit. These are not all scenarios, but are the most common.
Scenarios are located in Appendix A.
3.7.4 Estimated Component Costs
The following table (Table 7) lists component costs and where the component was
purchased from. As long as there are no unexpected component costs, the end product
will be within the anticipated construction costs.
Table 7: Estimated Prices
Part Description Cost Purchase locationLCD Display Output device that displays
numbers and letters.$10 Radio shack
12-button keypad Input device that allows combinations of 12 different keys.
$7 Radio shack
PIC microcontroller with interface board
Programmable microcontroller with connector board.
$15 Online from manufacturer
Low voltage power supply
Supplies low voltage supply with an input from 120v.
$10 Digikey.com
Wires and connectors
Miscellaneous wires and connectors.
$10 Radio shack
Coin mechanism Allows the input of up to 8 quarters as a form of payment. Mechanism is metal.
$25 www.pb.com
Coin mechanism relay
Simple relay. $3 Radio shack
120v socket 3-prong socket. $5 Lowes240v socket 4-prong 240v socket. $5 LowesBox The box that the unit will be
placed in. Sheet metal$10 Lowes
240v power cord Power cord. $3 Lowes
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4.0 Resources and Schedules
The resource and schedules are outlined in following sections; personal effort, other
resources, financial budget, and schedules.
4.1 Personal Effort Budget
Listed in Table 8 is the predicted effort required from each team member to contribute to
the finalized project. The hours vary from student to student depending on their sectional
interests, but the total hours are within proximity of each other.
Table 8: Personal Effort Budget
Task Greg Herr
Craig Zamzow
Latrice Baggett
Hisham Chowdhury
Total Task
HoursOriginal / Revised
Original / Revised
Original / Revised
Original / Revised
Documentation 28 / 32 28 / 30 27 / 29 20 / 22 103 / 113Presentations 10 / 11 11 / 12 10 / 11 8 / 10 39 / 44Meetings / Design 40 / 45 40 / 45 40 / 45 40 / 45 160 / 180Research 15 / 20 14 / 19 15 / 20 15 / 20 59 / 79Obtaining Hardware 7 / 7 8 / 8 10 / 9 8 / 7 33 / 31
Coding 10 / 11 10 / 11 8 / 8 11 / 11 39 / 42Debugging / Testing 12 / 12 11 / 12 9 / 10 13 / 14 45 / 48
Assembly 12 / 15 13 / 16 12 / 14 15 / 16 52 / 61Final Testing 14 / 15 13 / 15 13 / 15 12 / 14 52 / 59Totals 148 / 168 148 / 168 144 / 161 142 / 159 582 / 657
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4.2 Other Resources
The extra cost of items that were omitted when initially determining the costs involved in
the project is shown in Table 9.
Table 9: Additional resources.Item Team Hours Cost
Document Binding 2 $8.00Spray Glue – Poster 1 $4.00Poster Board – Poster 1 Donated
Total 4 $12.00
4.3 Financial Budget
The cost of parts will need to be below $100 for the control system to be made. Since
some of the parts were already bought by last year’s team for this project, there should be
no problem in trying to stay under the part budget. The Team spent $40 for the project
poster. Table 10 outlines the expected costs.
Table 10: Financial BudgetItem W/O Labor With Labor
Parts and Materials: Original / Revised Original / RevisedParts $85.00 / $85.00 $85.00 / $85.00Poster $50.00 / $40.00 $50.00 / $40.00
Subtotal $135.00 / $125.00 $135.00 / $125.00
Shipping: $15.00 / 15.00 $15.00 / $15.00Subtotal $15.00 / $15.00 $15.00 / $15.00
Labor at $10.50 per houra. Latrice Baggett $1,512.00 / $1,690.50b. Craig Zamzow $1,554.00 / $1,764.00c. Greg Herr $1,554.00 / $1,764.00d. Hisham Chowdhury $1,491.00 / $1,669.50
Subtotal $6,111.00 / $6,888.00Total $150.00 / $140.00 $6,261.00 / $7,028.00
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4.4 Project Schedule and Deliverables
Figure 5 shows the revised schedule for the first half of the project. It has been split up
into three parts: the requirement phase, design phase, and the development phase. This is
a schedule of the team’s activities from August-December 2003.
Figure 5: Gantt chart for Fall Term
Figure 6 shows the revised schedule for the second half or the project. It has been split
up into two phases: the development phase and the testing phase. This is a schedule of
the team’s activities from January – May 2004.
Figure 6: Gantt chart for Spring Term
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Figure 7 shows the revised deliverable schedule for fall 2003 and spring 2004.
Figure 7: Deliverables for Senior Design Fall and Spring Semesters
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5.0 Project Team Information
The group’s information includes details such as major, first and last name, email
address, and phone number to allow all group members to easily communicate with each
other.
CprE EE
Greg Herr Latrice Baggett
(515) 292-0453 (515) 572-7727
127 ½ Welch #101 4112 Frederiksen
Ames, IA 50014 Ames, IA 50010
[email protected] [email protected]
CprE CprE
Craig Zamzow Hisham Chowdhury
(515) 572-5023 (515) 441-0752
1250 Friley Dodds 4605 Ontario St. #5
Ames, IA 50012 Ames, IA 50014
[email protected] [email protected]
Client Advisor
George Ensley Dr. Ratnesh Kumar
1-800-397-6453 (515) 294-8523
723 Story St. 3217 Coover
Boone, IA Ames, IA 50011
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Advisor
Dr. Nicola Elia
(515) 294-3579
3131 Coover
Ames, IA 50011
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6.0 Summary
The cost and proprietary mechanisms of commercial coin-operated washer/dryers are
limiting the potential of laundromat businesses. The team’s client, George Ensley, has
envisioned a separate coin mechanism to allow the use of non-commercial washer/dryers
in his laundromat business. The team’s approach will consist of integrating a
microcontroller with solid-state electrical components to control the flow of electricity to
the washer/dryers. The use of non-commercial washer/dryers will allow laundromat
owners to have lower initial costs and higher resale values for their washers and dryers.
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7.0 References
Phase1 DocumentsProject PlanFinal ReportFunctional Diagram
Phase 2 DocumentsProject Plan
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8.0 Appendix A
The scenarios that a possible user may go through when using the washer/dryer coin-
operated system.
Scenarios:
Customer:
Scenario 1: Customer with a regular load of laundry in a washer.
Customer approaches washer with load of dirty laundry.
Customer loads the washer.
Customer inserts coins into slots and pushes in on the mechanical arm.
Power is delivered to the washer; the client sets the controls and starts the
machine. The LCD will display the remaining minutes.
The washer finishes washing the clothes after 30 minutes.
3-4 minutes later, the power is cut from the washer, and the next customer may
insert money to use the machine.
Scenario 2: Customer with regular load interrupts the washer.
Customer approaches washer with load of dirty laundry.
Customer loads the washer.
Customer inserts coins into slots and pushes in on the mechanical arm.
Power is delivered to the washer; the client sets the controls and starts the washer.
The LCD will display the remaining minutes.
After 10-15 minutes the customer opens the washer door to add fabric softener.
The door is left open for 5 minutes; during that time the overall timer is paused.
When the door is shut and the machine resumes, the overall timer resumes.
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The washer finishes washing the clothes after 30 minutes.
3-4 minutes later the power is cut from the washer, and the next customer may
insert money to use the machine
Scenario 3: Customer with load of wet laundry in a dryer.
Customer approaches dryer with load of dirty laundry.
Customer loads the dryer.
Customer inserts coins into slots and pushes in on the mechanical arm.
Power is delivered to the dryer; the client sets the controls and starts the machine.
The LCD will display the overall remaining minutes.
After 30 minutes the customer opens the dryer door and removes his or her dry
clothes.
The LCD will display a 5 minute timer in seconds.
After the 5 minute timer expirers the power is cut from the dryer and the coin
operated control unit resets itself to be ready for the next customer.
Owner:
Scenario 4: Owner changes the door timer.
Owner opens box of control unit.
Owner presses ‘#’ + a six digit code to enter maintenance mode.
The LCD informs the owner to press 1 to change the door timer, press 2 to change
the cycle timer, press 3 to read the cycle count, and press 4 to reset the cycle
count.
The owner presses 1, to change the door timer.
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The LCD prompts for the new value.
The owner enters the time in seconds.
The LCD prompts to verify the new value, asking the owner to choose “yes” or
“no” to verify.
The LCD displays the maintenance main menu.
The owner presses ‘*’ to exit the main menu.
The control unit goes back to the idle state and prepares to help any approaching
customers.
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Team Testing Form:
Form for Project Testing ProcessTeam
Member(s)Date/ Time Location Process
Tested Comments on Tested Process
Detailed Description of Activities Done:
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