Final Report
ARBY’s Bathroom Entry and Soap Dispenser Detection using RFID
ECE4007 Senior Design Project
Section L03
Team ARBY’s RFID
Project Advisors, Arthur Koblasz and Christopher James
Paul Chang
Joe Contreras
Alejandro Gari
Submitted
December 10, 2009
Table of Contents
Executive Summary ......................................................................................................... iii
1. Introduction.................................................................................................................. 1
1.1
1.2
Objective ............................................................................................................. 1
Motivation ........................................................................................................... 2
2. Project Description and Goals .................................................................................... 3
3. Technical Specification ................................................................................................ 4
4. Design Approach and Details ..................................................................................... 7
4.1 Design Details ....................................................................................................... 7
4.2 Codes and Standards ............................................................................................. 9
5. Schedule, Tasks, and Milestones .............................................................................. 10
6. Results and Acceptance Testing ............................................................................... 12
7. Budget and Cost Analysis ......................................................................................... 13
8. Conclusions and Future Work ................................................................................. 16
9. References ................................................................................................................... 17
Appendix A ....................................................................................................................... 18
ii
Executive Summary
The Arby's Bathroom Entry and Soap Dispenser Detection system is an automatic and costeffective system that detects entry of an employee into a restroom, use of the soap dispenser, and exit
out of the restroom. If an employee does not dispense soap, real-time data logs are written to notify
management of improper employee hygiene so management can check the logs at the end of every
workday. The system is comprised of an RFID transceiver board for bathroom entry and exit tag
detection, a motion sensor, an IR sensor for soap dispensing detection, an antenna mounted on the
restroom door way for RFID tag reading, and a system computer. The system computer receives data
from the RFID and IR sensors and processes the data through an algorithm.
The Arby's Bathroom Entry and Soap Dispenser Detection system allows management at food
service establishments to monitor the hand hygiene activities of their employees who have used the
restroom. This system ensures that high standards of food safety and quality are maintained at these
establishments. The system decreases the chance of food contamination via employees not following
proper hygiene.
Designing and manufacturing the Arby's Bathroom Entry and Soap Dispenser Detection system
is estimated to cost $1,815.00. With a target pricing set at $2,500, a 30 percent profit is attainable.
Our large-quantity pricing will cost $2,200 per system when a franchise purchases at least 10 systems.
The finished product is expected to be installed in the restrooms of food service restaurants.
The system will be a ready-to-market product targeted at food service chains. Depending on the setup
of the restroom, the system has to be coded differently. However, Arby’s restaurants have singleoccupancy restrooms and that is the setup we are basing our system on.
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1.
Introduction
Designing the bathroom entry and soap dispenser detection system is estimated to cost
$1,815.00 for the necessary components. There are many different components that comprise
the system such as an RFID tag, a reader, an antenna, an eBox, motion sensor, and a soap
dispenser with an IR sensor.
1.1
Objective
Arby’s franchise restaurants are looking for a system to address employee hygiene, which
is an area of concern in regards to the quality of food for customers. The team is planning to use
radio frequency identification (RFID) to detect whether an employee uses the soap dispenser
while occupying the restroom. Furthermore, our secondary goal is to keep track of employees
when entering and exiting the restroom. The worker’s RFID tag will be read at the entrance of
the restroom where the reader is placed. A picture of the RFID tag is shown in Figure 1.
Figure 1. RFID tag used in hand washing detection system.
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A motion sensor is a major component of our system because the restrooms are singleoccupancy therefore a motion sensor can help identify false alarms. A proprietary software
algorithm will keep a log of each employee’s hygiene efficiency.
1.2
Motivation
Creating a higher standard in the food industry for personal hygiene is a key motivating
factor for the project proposal. Food poisoning is a dangerous, yet preventable symptom of
consuming ill-prepared food. The most common way for an individual to consume food
containing dangerous microbes that come from the handler of the food is through its preparation.
The team feels that the RFID system will be beneficial to keeping restaurant environments free
of microbial infections.
There is an existing patent filed in February 1998 for a hand washing monitoring system
[1]. There is also a team from a previous semester that successfully attempted a similar system
using kitchen entry detection and a magnetic door lock. The new design uses a passive RFID
reader to detect an employee’s tag around his/her wrist to detect restroom entry. The target
customers for this system are restaurants, where handling food is necessary prior to serving the
consumers.
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2.
Project Description and Goals
The Arby's Bathroom Entry and Soap Dispenser Detection system will allow
management to automatically monitor the hand washing activities of employees who have used
the restroom. The system will incorporate an RFID sensor located at the restroom entrance for
entry/exit detection. An IR sensor will detect when an employee dispenses soap. If an employee
fails to activate the IR sensor, after exiting the restroom, the data log will contain all information
regarding employee actions. A log in the system computer will also be updated with the
employee's information.
The main difference between our proposed design and the actual design is the deletion of
the real-time alarm. A real-time alarm is not logical considering the manager of fast food chains
usually work alongside employees outside of the office. A real-time alarm located in the office
or near the customer stand would also be a distraction to the manager, employees, and customers.
Arby’s restrooms are single-occupancy; therefore a motion sensor component is added to our
system to differentiate between an occupied restroom and a false alarm.

Detect entry and exit of employee

Use motion sensor to detect employee

Detect use of soap dispenser via IR sensor

Logging of RFID tag data

Priced at $2,500

Targeted for restaurant and food service industry
3
The goals from the original proposal are met with our current system, except for the real-time
alarm. The RFID tag is worn on the right leg of the employee so the reader will be able to detect
the tag easily unless the worker walks inside the bathroom backwards. This also eliminates the
confusion of having the worker wear an RFID tag on both wrists. The original design increased
by $86.00 from the addition of the motion sensor and soap dispenser.
3.
Technical Specifications
The core of the Arby's Bathroom Entry and Soap Dispenser Detection system is the
eBox-2300 computer. One RFID transceiver board is mounted on the door inside a mounting
bracket. The transceiver board interfaces with the computer, through a USB connection. The
RFID sensor will be located near the person’s lower part of the leg about 6-12 inches from the
ground for optimal reception where employees will be asked to where the RFID tag as a ankle
band. The IR sensor will interface with the computer through either a USB connection. A
detailed picture of our system is shown in Figure 2.
4
Figure 2. Arby’s bathroom entry detection system mounted to testing station.
A reset time window will allow the software to reset its state if it falsely detects an employee
entering the restroom. For our design purposes detecting two employees will be unnecessary
since Arby’s restaurants have single-occupancy restrooms.
5
Feature
RFID Sensor System
Number of sensors
RFID Technology
RFID Antenna - Range
Interface w/ computer
Location
Sensor System
Number of sensors
Interface w/ computer
Location
Computer
Model
Architecture
Reset time window
Power Supply
Dimensions of computer
housing
Alarm
System
Notification
Interface w/ computer
Specification
1
13.56 MHz with passive tags
≤ 30 cm with pad antenna
USB or serial
Door
2
USB
Soap dispenser and Room
eBox-2300
x86
15 minutes
AC adapter +5V @ 2A
115 mm x 115 mm x 35 mm
LED and speaker
Serial and USB
Table 1. Design Specifications
A proprietary program written in C/C++ will receive and interpret the data from the
sensors to determine if an employee hand washing violation has occurred. The two inputs of the
program are the motion sensor and infrared sensor on the soap dispenser. The two inputs are
sent to the program by connecting the inputs to a mouse. The program is able to detect mouse
clicks as inputs and writes to a text file according to the situation. If a violation is detected, the
system will notify management. The program will be loaded onto eBox-2300 [2], specified in
Table 1.
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4.
Design Approach and Details
4.1
Design Details
The design layout of the Hand Washing Detection system can be seen in Figure 3. As,
seen below, an RFID sensor will be mounted near lower part of the door. An RFID tag will be
worn by all employees near their ankle. As the employee opens the door, the system will detect
entry and the system computer (placed in the upper right hand corner of the room) will record the
data.
Figure 3. Shown above is a schematic of the design layout.
As the employee washes his/her hands and dispenses soap, an IR sensor will be triggered.
This is the ideal situation when an employee is using the restroom; however, the program also
takes into consideration for non-ideal situations. An employee can set off the sensor by walking
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near the restroom while mopping, therefore a timer for the motion sensor will start. If the
employee does not trigger the motion sensor inside the restroom in less than five seconds, the
program will automatically restart. Also, if the motion sensor is triggered and the soap dispenser
is not detected via the infrared sensor in less than five minutes, the program will automatically
restart again.
The system computer used is an eBox-2300. The eBox-2300 will be running on
Windows XP. An algorithm will be programmed, using C/C++, into the eBox-2300 which will
analyze the data and determine if the employee has washed his/her hands. If the system has
detected that an employee has not washed his/her hands and dispensed soap, an LED light
flashes to show if the sensors are working correctly. A picture of our circuit box with the LEDs
is shown in Figure 4 and the schematic of the circuit is shown in Figure 5.
Figure 4. Sensor link box circuit for hand washing detection system.
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Figure 5. Schematic of circuit used in hand washing detection system.
Our system’s main plan of action for employees not washing hands is to have data logs
recorded. The data logs will be detailed and able to detect errors when employees pass by the
restroom but do not enter. The data log of employee hygiene efficiency will be stored on the
manager’s computer, where the manager can check at the end of every shift, to see if employees
have been following proper hygiene.
4.2
Codes and Standards
A design consideration for the hand wash monitoring component is to use a camera
to compare a soapy hand as compared to a dry hand. However, due to privacy regulations for
restrooms, the infrared detector is a more ethical choice than the camera. There are also
regulations set by OSHA to protect people from RF radiation exposure [3]. Due to the
9
regulations, the team considered the amount of RF radiation exposure differences between active
and passive RFID tags. The passive RFID tags are a safer route for employees wearing the tag
while working on duty, since the RFID system radiates at a lower power.
5.
Schedule, Tasks, and Milestones
The Arby's Bathroom Entry and Soap Dispenser Detection system will be designed,
constructed, and tested during the next three months. The tasks have been placed in functional
groups that follow a chronological order. The milestones bolded in Table 2 are design,
construction, testing, and deliverables. The design milestone will be achieved on September
13th, the construction milestone will be achieved on November 13th, the testing milestone will be
achieved on November 11th, and the deliverables milestone will be achieved on December 10th.
Each task is assigned a corresponding difficulty that correlates to the amount of time required for
that task. The Gantt chart in Appendix A is an extension of Table 2 showing task division
among team members.
10
Task Name
Design
Brainstorming
Proposal
Duration
11 days
7 days
4 days
Construction
Order Parts
Programming
Prototyping
Door
Door
Unit
Assembly
Soap
Assembly
Antenna
Dispenser
Assembly
Testing and
Debugging
51 days
6 days
6 days
10 days
4 days
7 days
7 days
11 days
Low
High
Medium
Low
Medium
Medium
High
19 days
High
Deliverables
Website
Final
Project
Creation
Final
Project
Presentation
Final
Project
Demonstration
Report
9 days
6 days
1 days
1 days
1 days
Medium
Medium
Low
Low
Low
Difficulty
Medium
Medium
Table 2. Tasks and Milestones
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6.
Results and Acceptance Testing
The Arby’s RFID team will be demonstrating the Hand Wash Detection system to the
professors of Section L03, and to an Arby’s administrator. The team will be using a small
section of a door to simulate an employee entering and exiting the restroom. A soap dispenser
will then be mounted on a piece of plywood. A team member will simulate various scenarios
that may be encountered by the system.
The first scenario will be the ideal situation of an employee entering, using the soap
dispenser, and then exiting the restroom. The second scenario will be if an employee simply
opens the door, possibly for a customer, but does not enter the restroom. The third scenario will
be if the employee needs an extended period of time in the restroom. The last scenario
demonstration will consist of an employee opening the door for a customer and a short while
later entering the restroom. During the design process, each of these scenarios will be tested by
triggering the sensors accordingly with the desired amount of time between triggering of sensors.
The program responds well to the different scenarios. The program being able to run a
thread helps immensely. Creating events also aids the program in timing the events and waiting
for signals. All specifications were met when testing our system in the different scenarios. The
most difficult part of the program was figuring out how to time the events and break out of the
program when the situation was not ideal.
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7.
Budget and Cost Analysis
The two primary markets for the RFID hand washing detection product are the restaurant
and food industries. The benefits this product will supply to our customers are assuring
restaurant owners that their employees are meeting the hand sanitation codes. The team’s
promotion strategy will be giving restaurant customers a guarantee that their food will be
handled by employees with clean hands, thereby reducing the chance of contracting food
poisoning. The product’s functionality will be tested in an Arby’s fast food restaurant to insure
that the design works properly.
A similar product has been patented by Richard J. Melker, Christopher D. Batich,
Nikolaus Gravenstein, and Donn M. Dennis. Their design is called “Hand Washing Compliance
Detection System” [4]. This system provides a hand washing agent with a detectable, volatile
compound, such as odors, which is then rubbed onto a subject’s hand. After the hand washing
event, the subject’s hand is then exposed to a detector (such as a badge), which includes a sensor
capable of detecting the volatile compound, and an indicator that communicates detection of the
volatile compound.
The RFID system design is used to detect the same functionality as the above design.
The difference with the RFID design will be to also detect when an employee has entered and
exited the restroom. The above design does not guarantee that an employee, who has entered the
restroom, has washed his hands.
The total cost for funding the design, testing, and research for the Hand Washing
Detection product is estimated to be $29,356, shown in Table 3. The cost of each component of
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the design can be seen in [5]. The suggested selling price has been determined by estimating
that 200 systems are sold in period of five years. The cost of manufacturing each system is
approximately $1,815. To cover the cost of manufacturing and sales expense, and produce a
profit, the price for each system will be priced at $2,500.00. Over a period of one year, the
estimated profit will be $30,000. At the price stated above, there will be an investment return
rate of approximately 30 percent.
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Hours
Cost of
Labor/Hr
Amount
Cost
Prototype
RFID Readers
2
$1164
Power Supply Cables
2
$164
Antenna
1
$252
RFID Tag
1
$30
Soap Dispenser with IR
1
$50
Motion Sensor
1
$36
Ebox
1
$119
Design/Research
Alejandro Gari
306
$30
$9,180.00
Joe Contreras
306
$30
$9,180.00
Paul Chang
306
$30
$9,180.00
Total Cost
$29,356
Table 3. The Cost Analysis of RFID Hand Wash Detection System
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8.
Conclusions and Future Work
Currently, our system is connected together and the program is working properly.
Testing the different scenarios required changing the timers for the soap dispenser and motion
sensor events. Changing the timers enabled us to test for different scenarios in a quick and
efficient manner. The only change that would be necessary in order to implement our system
into all fast food chains would be to have a program that could handle multiple threads and
multiple RFID tags. Luckily, Arby’s restaurants have single-occupancy restrooms making it
easier to write an algorithm for our system. All initial goals have been satisfied by our system
since the system is able to read RFID tags, differentiate a false alarm from an employee using the
restroom with a motion sensor, have adjustable timers, and create data logs of bathroom activity.
There are ways to improve upon our design and make it more versatile. Using a semiactive RFID system could be beneficial when designing a system for multiple-occupancy
restrooms. Also, if this approach would have been taken, our program algorithm would also
need changes to compensate for multiple employees in the bathroom. Currently, the designed
system is ready for production for Arby’s restaurants.

Create a system that can operate for single and multiple occupancy restrooms

Work on program algorithm early in the design process

Use semi-active or active RFID system for extra flexibility

Use LED badges that show manager in real-time whether employee washed hands
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9.
References
[1]
R. C. Johnson, “Apparatus and method for monitoring hand washing,” U.S. Patent 6 038
331, February 17, 1998.
[2]
EmbeddPC.NET. (2009, September). "eBox-2300 Compact PC". [Online]. Available:
http://www.embeddedpc.net/eBox2300/tabid/110/Default.aspx. [Accessed: September
14, 2009].
[3]
Occupational Safety & Health Administration. (2009, September). "OSHA Regulation
for RF Radiation Exposure. [Online]. Available: http://www.osha.gov/SLTC
/radiation_lectures/ rfradiation.ppt. [Accessed: September 14, 2009].
[4]
R.J. Melker, C.D. Batich, N. Gravenstein, D.M. Dennis, “Hand washing compliance
detection system,” U.S. Patent Application 20080303658, June 8, 2007.
[5]
Dynasy. (2009, September). “RFID USA - One Source for RFID - Radio Frequency
Identification - RFID Solutions”. [Online]. Available: http://www.rfidusa.com.
[Accessed: September 15, 2009].
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Appendix A
Table 3 -- Gantt Chart
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