Multi-Disciplinary Engineering Design ConferenceKate Gleason College of Engineering

Rochester Institute of TechnologyRochester, New York 14623

Project Number: 07002

DESIGN OF A TWO-WAY COMMUNICATION DEVICE

Aisosa Ayela-UwangueElectrical EngineerComponents-Power Lead

Nathan HollandMechanical EngineerCase Design Lead

Zemma KassaElectrical EngineerSoftware Development Lead

Scott KellerMechanical EngineerHeat Transfer Lead

Glenn SnyderElectrical EngineerUser Interface Lead

Matthew TiceElectrical EngineerProject Manager

ABSTRACT

The Rochester Institute of Technology (RIT) welcomes both deaf and hard of hearing students into its National Technical Institute for the Deaf (NTID). These students are able to attend classes regularly, being accompanied with an interpreter. However, when deaf and hard of hearing students seek extra help during professor office hours or tutoring sessions, interpreters are not always available. Faculty and tutors at the Rochester Institute of Technology found that communicating with deaf and hard-of-hearing students proved to be a demanding task. The current method of communication with these students is slow and frustrating, limited to a communication method consisting of handwritten notes. The goal of this project was to design a device that would allow users to communicate rapidly with a professor or tutor. The project team designed a device that uses a messenger style interface. The communication method allows users to type to each other, while any relevant phrases will be auto-completed to increase efficiency of communication. This project will enhance the learning experience for the NTID students by easing the method of communication with the professor or tutor.

INTRODUCTION

As the deaf and hard of hearing student population grows at Rochester Institute of Technology,

communication between these students and professors has raised a problem. Interpreters cannot provide continual assistance to deaf and hard of hearing students when the students need to communicate with professors after class. The method of communication during this time is limited to hand written notes, which has been proven to be a very slow and tedious task. A need was expressed by NTID students and mechanical engineering professor, Dr. DeBartolo, for a device that would allow fast and efficient communication between NTID students and RIT professors.

A design team was selected and organized into separate subsystems. A project manager was selected as well as a lead for each sub-system of the project. The sub-systems included components and power, case design, software development, heat transfer and user interface development. The design team met with Dr. DeBartolo immediately in order to interview the primary customer and define the customer needs. The team also met with two NTID engineering students, one who is deaf and the other one hard-of-hearing. The first need described by the customers was a need to communicate in a quicker fashion than hand written conversations. The device also needed to be portable to ensure travel between professors’ offices. Since students would be using this device in the tutoring office as well, it needed to be durable and resist liquid spills. Proper security precautions needed to be taken as well in order to

© 2007 Rochester Institute of Technology

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prevent the device from being stolen. Other needs expressed by the customers included accommodations for visually impaired users, internet access, device rotating capability, low power consumption, design within budget of $1,200, and easy to use. After recording the needs expressed from the customers, the design team began the benchmarking phase. Products that performed similar tasks as the ones described by the customers included a word processor on a laptop and the Interpretype. A laptop computer allows students and professors to type text phrases to each other in a word processor. The user can then save the conversation for later reference. However, not all students own a laptop that can be used for this method of communication. The Interpretype is also a device used by NTID students as a method of communication. The device allows users to communicate by typing single phrases at a time. However, the device does not allow for users to save the conversation. These devices are not readily accessible to professors or students in the engineering building. After researching the capabilities of current communication devices used by NTID students, the design team reviewed the needs presented by the customer and determined which aspects of the needs were critical to the quality of the design. Metrics were then assigned to each need in order to provide a means of determining how well the design met the required specifications. The need assessment matrix is available on the team’s website [1] under the title of “Need Assessment”.

DESIGN PROCESS

Design_Specifications After the customer needs were documented, a weight of 9, 3, or 1 was assigned to each need, with 9 indicating the highest priority and 1 the lowest. This method was used to generate the design specification matrix, which is available on the team’s website [1] under the title of “Design Specifications”.

The needs with the highest priority rating included cost, design within team programming capability, lightweight, proper dimensions, proper display size, appropriate processor speed and RAM, proper level of heat dissipation, adequate security precautions, means of graphical tools, water-resistant design, detailed user manual, easy of use, adequate coverage of mechanical and electrical engineering concentrations and easy to update.

The cost needed to stay within the budget of $1200.00. In order for the device to be portable, it had to weigh less than 8 lbs and have dimensions no greater than 12 x 10 x 2 inches. The processor speed and RAM

needed to be fast enough to accommodate the proper software design. Tests were performed to determine minimal processor speed and RAM size. When generating the design specifications, it was important for the team to consider the capability for future expansion of all components. In order to protect the selected electronics, proper cooling measures needed to be taken. The training for use of the device had to take less than 15 minutes and the software needed to provide update capabilities in less than 4 steps. Other properties of the device that needed to be included were a water-resistant case that is easy to clean as well as a detailed user manual.

Needs that were considered to have moderate to little importance included rotating capability of the device, a low power mode, a method to save the conversation for viewing at a later time, internet access, ease of cleaning and a protective carrying case.

Brainstorming_SolutionsOnce the design team fully documented and understood the customer needs and design specifications, solution ideas were generated. Different brainstorming activities occurred in order for an exhaustive list of suggested solutions to be created. The team participated in an affinity diagramming exercise in order for several initial solutions to be suggested. Other brainstorming activities included discussions with professionals, professors and NTID students and recording the resulting suggestions.

Concept_GenerationThe design team documented and reviewed every solution that was suggested for the customers’ needs. The team then researched each concept that was suggested and documented specifications for each. Among the specifications that were collected was pricing, manufacturer, dimensions and other characteristics. After extensive research was performed on each idea, complete device concepts were drafted. The complete list of generated concepts is available on the team’s website [1] under the title of “Concept Generation”.

PRELIMINARY DESIGN

Hardware The hardware components of the Two-Way Communication device are a single board computer, a power supply, and Liquid Crystal Display LCD.

The single board computer is the brain of the device. It is comprised of a micro-processor and memory. The following criteria were used to select the most suitable single board computer:

(a) Cost: The price of the single board computer had to be within the $1200 budget of the project.

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(b) Size: The single board computer had to be small enough to meet the overall case dimension specifications.

(c) Platform or Operating System it supports: The single board computer had to support Embedded Linux operating system.

(d) Processor Speed: Research showed that the minimum processor speed to run Embedded Linux is 386 MHz [2]. Hence the single board computer had to have a processor speed of 386 MHz or greater.

(e) Memory Size: Research showed that the minimum Random Access Memory RAM needed to run Embedded Linux is 4 MB [2]. Similarly, the single board computer had to have a RAM of 4 MB or higher

(f) Hard Drive Size: Research showed that Embedded Linux required at least 40 MB of storage [2]. Benchmarking results also showed that this hard drive size was sufficient for the application.

A matrix comparing various single board computers from different manufacturers using the above criteria is available on team’s website [1] under the title of “Pre-Read Design Review 1”. Based on those criteria, PCM-9371 single board computer was selected [3]. This board has 650 MHz of processing speed, 128 MB of DRAM, and 1 GB of Compact Flash Drive. Detailed features and additional specifications of PCM-9371 are available on the team’s website [1] under the “Manual” subsection.

Size was the main criterion for selecting the appropriate LCD. The LCD had to be small enough to fit within the overall case dimension specification. Compatibility with PCM-9371 single board computer was another criterion for selecting the LCD. Further inquiry revealed the same manufacturer also provided LCDs that are compatible with its single board computers and met the team’s size criterion. Hence, a 10.4 inch LCD was purchased [3]. Additional specifications of this component are available on the team’s website [1] under the “Manual” subsection.

The power requirement for the PCM-9371 single board computer is 14 Watts and 5 Amps. Initially the goal of the team was to purchase the hardware components from the same manufacturer to avoid compatibility issues. Hence, the team selected a 150 W ATX power supply from the PCM-9371 manufacturer [3]. This was the minimum power supply rating it offered that met the single board computer’s power requirement. However, this power supply significantly increased the overall case dimensions and violated the design specification. In order to meet the

case dimension specifications, an alternate power supply that generated 60 W was selected from a different manufacturer [4]. Additional specifications of the power supply are available on the team’s website [3] under the “Manual” subsection.

Software_Development Software development is one of the main components of the project and it includes the selection of the appropriate operating system, programming language to be used, and the Graphical User Interface (GUI). Preliminary design for the software development started with selecting the appropriate operating system that will accommodate the single board computer. Embedded version of Debian Linux was chosen as the operating system because of its capability to run with a smaller processing speed than a Windows operating system. Furthermore, the supplier of the single board computer [2] was willing to provide a customized version of Embedded Linux along with X-Windows and one year technical support.

Initially, QT software program development environment [5] was chosen to build the GUI because of its drag-and-drop capabilities that simplified the process. However, some software applications still required coding in C++ programming language, which made using QT software program development environment difficult for the team to learn and complete the task within a limited time frame of ten weeks. After seeking advice from professors and fellow students, the team decided to change the programming language from C++ to Java. This change meant that the team could no longer use QT as its software program development environment. Java programming language is a high-level language that is widely used for GUI development and Web applications. It can be run on different platforms such as Windows, Linux, Solaris, and Mac [6]. This cross-platform capability made Java very well suited for the application of this project.

The design of the GUI was arrived after several meetings setup to solicit ideas from deaf and hard of hearing students as well as tutors and professor. An “instant messenger” style design of the GUI was found to be most effective in meeting customer requirements. This was customized for Electrical and Mechanical Engineering students by creating two different work windows. In order to accommodate the remaining customer needs, the GUI was designed to contain the following added functions below:

(a) Adjustable font size

(b) Session saving capability: With this feature, the user can save the conversation into a flash or jump drive, which can be retrieved later.

Copyright © 2007 by Rochester Institute of Technology

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(c) Start new session capability: This feature enables the user to start a new session with just a press of a key.

(d) Auto-complete for phrases and sentences: This feature reduces typing time by auto-completing phrases or sentences that have already been typed by another user and added to the database.

(e) Suggested phrase and sentences: This feature also reduces typing time by allowing the user to select from a list of sentences that start with the same word he or she has typed.

(f) Database update: With this feature, the user is able to add phrases or sentence to the database.

Case Design: Several methods and processes were evaluated and used to determine a case design that would be implemented. Two concepts were conceived after evaluating the rubrics involving customer needs and design specifications. The first concept was to create a laptop casing. The second was to fabricate a type of notebook computer design. Both proposals are modeled in Fig. 1. below.

Figure 1: Concept Design for Casing

The first concept has an enclosed LCD that is hinged and attached to a base. The base encloses the Single Board Computer (SBC). The use of a mouse or touchpad was yet to be determined at this point. The keyboard is recessed onto the base as shown in Fig. 1.

The second of these concepts resembles a notebook computer or that of a graphing calculator but on a larger scale. The LCD, SBC, and keyboard are enclosed by the casing.

Using a solution prioritization matrix, the first of these concepts was selected for implementation. When the concept was presented, the customer specified their wishes that the casing should not be a prefabricated laptop shell, but that it should require some construction and alteration to fit their needs. The addition of a swivel underneath the case, allows the device to be rotated to each user’s viewpoint. Figure 2

below shows the initial design with all the internal components and power supply.

Figure 2: First Concept Computer Aided Drawing

ENGINEERING MODEL

Software_Development QT software development environment was used to create a template of the GUI. Figure 1 below shows the initial template design for the GUI.

The quick keys or function keys shown in Fig. 3. below have the following functionalities:

(a) F1: When the user presses this key on the keyboard, a copy of the conversation is saved as a text file.

(b) F2: When the user presses this key on the keyboard, the font size in the conversation box decreases.

(c) F3: This key is used to increase the font size in the conversation box.

(d) F4: This key is used to add a phrase or a sentence typed in the text entry box to the database.

(e) F5: This key starts a new session.

Function keys are used for navigation instead of a mouse to increase portability of the device. However, programming the function keys, the auto-complete and suggested phrase features using C++ programming language was beyond the team’s programming capabilities. Hence QT was only used to create the template and not those functionalities.

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Concept 1 Concept 2

Concept 1 Concept 2

Power supply

Swivel

SBC

Power supply

Swivel

SBC

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Figure 3: GUI Design Model

Case_Design The case was fabricated in the Mechanical Engineering machine shop using Ultra High Molecular Weight (UHMW) Polyethylene. However, this case did not meet customer requirements in terms of size and aesthetics, hence the need for a new design. The current redesign involves the use of a donated prefabricated plastic enclosure [7]. Figure 4 shows a picture of the casing along with a Computer Aided Drawing (CAD).

Figure 4: Final Case Design

The keyboard is an externally connected peripheral that is not included in Fig. 4. The material is made from ABS 94-HB (Acrylonitrile-Butadiene-Styrene). Detailed specifications on the material are available on the team’s website [1] under the “Manual” subsection. Its dimensions are 11 x 7.9 x 3 inches. It has a top and bottom cover, and an input/output panel. The input/output panel will be used to access the SBC. The LCD will be mounted onto the top panel. An additional interior panel will be screwed to the tapped holes in the interior of the bottom cover. The SBC and the power supply will be mounted on it. The implementation will be such that the SBC will be

elevated slightly with plastic spacers. A slot will be made into the interior panel for placement of the power supply, which will be clamped down and secured.

Thermal_AnalysisIn order to protect the single board computer from damage produced by self-heating, an analytical analysis was performed. The airflow rate required to dissipate the heat generated by the electronics was calculated using equation 1.

(1)

In (1), q is heat energy, m is the mass flow rate of air, CP is the specific heat of air, Tmax is the maximum temperature the electronics will reach and Ta is the ambient temperature of the air. The amount of air that is required to adequately cool the device was then determined and found to be 1.205 ft3/minute. This metric could then be used to research and purchase a fan to be used for heat dissipation.

EXPERIMENTAL SETUP AND PROCEDURE

Once the prototype was fabricated, a test plan was developed to document the methods used to test the design in terms of meeting the design specifications. The test plan consisted of clearly labeled instructions on how to carry out the test.

The first item tested was the cost of the device which was determined by referencing the bill of materials available on the team’s website [1] under the “Track of Purchases” subsection.

The second part of the design that was tested was the software component. The auto-complete and auto-suggest features were tested by having users type in commonly used phrases that were specified in the test plan. If the phrases were both auto-completed and auto-suggested, the device met the specifications. The device also had to be able to save the conversation to the users Universal Serial Bus (USB) mass storage device in order to pass specification. The test plan also provides instructions to test the adjustable font size feature as well as the update database function. The update database function needs to provide users with a means to update the database of commonly used phrases in 4 steps or less. The test plan also supplies a method to test the thoroughness of the user manual and customer training. Someone who has never used the device should be able to be trained in less than 15 minutes and be able to fully use the device

Copyright © 2007 by Rochester Institute of Technology

Student: Hi Dr. DeBartolo

Teacher: Hi Aisosa, what’s up?

I have a question on the homework

question on the lecture notes

question on this equation

reason to miss the next class

Concentration Tab

Conversation Box

Text Entry

Quick Keys

Phrase Auto-complete

Phrase Predictor

Font Size Indicator

Student: Hi Dr. DeBartolo

Teacher: Hi Aisosa, what’s up?

I have a question on the homework

question on the lecture notes

question on this equation

reason to miss the next class

Student: Hi Dr. DeBartolo

Teacher: Hi Aisosa, what’s up?

I have a question on the homework

question on the lecture notes

question on this equation

reason to miss the next class

Concentration Tab

Conversation Box

Text Entry

Quick Keys

Phrase Auto-complete

Phrase Predictor

Font Size Indicator

Rear view

Top view

Front view

Right Side view

Rear view

Top view

Front view

Right Side view

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and the provided features after reading the user manual.

The electronics were also tested to ensure that the device provided the user with adequate processing and RAM capabilities. The processor and RAM capabilities were tested by simply running the program and observe if there is any hesitation from the device. It also provides steps for the user to check the memory usage of the device in order to view how much memory is remaining while the program is running.

The case that encloses the electronics was measured with a ruler in order to determine the dimensions of the final design. The populated case was then weighed on a scale to determine the final weight of the device. The case was also crosschecked for water resistance and rotating capability.

To test the heat dissipation inside the case, temperature probes are inserted into the device to measure the steady state temperature. From the readings it could be determined if the cooling system is providing enough air flow in the interior of the device. While the casing has recently been changed to a slightly smaller design, the experiment and method of calculation remain the same. The complete test plan is available on the team’s website [1] under the “Main Documentation” subsection.

RESULTS AND INTERPRETATION

Software_Development Java programming language was chosen to develop the GUI for the two-way communication device. The complete source code is available on the team’s website [1] under the title of “Java Source Codes”. The final GUI model for the two-way communication device is shown in Figure 5 below.

Figure 5: Final GUI Design

In the final GUI design, some additions are made from the original model shown in Fig. 3. The additions include using the Tab key on the keyboard to toggle between the “Student” and “Professor” text entry boxes, and the F6 and F7 function keys to toggle between the Electrical Engineering “EE” and Mechanical Engineering “ME” concentration tabs respectively.

Table 1: Results of Test Plan

Test Variables Accomplished Not AccomplishedCost Yes $1147.06Auto-Complete Yes Suggest Phrase feature Still implementingSave Function YesUpdate Database Function YesAdjustable Font Size YesLight Weight YesDimensions Yes 11 x 7.9 x 3inDisplay Size Yes 10.4inRotating Capability YesProcessor Speed YesRAM Yes

Time Until Hibernation

N/A This feature is not needed because device is not powered with a battery

Heat Dissipation YesSecurity YesProvide Graphical tools to Users YesInternet Access YesWater Resistant YesEasy to Clean YesDetailed User Manual YesTraining YesAdequately cover ME/EE curriculumsYesEasy to Update YesNavigation Yes

The remaining features of the quick keys and phrase auto-complete capability function as expected from the concept model. However, the suggested phrase feature is still being implemented and is not currently included in the final GUI design.

The results from the final design are compared against the test plan developed and shown in the table below.

Table 1 above shows that over 95% of the original specifications were achieved. More work is still being done on the implementation of the suggested phrase feature.

RECOMMENDATIONS FOR FUTURE WORK

Currently the design is limited to a single physical device. This means that only one NTID student can use the device at any given time. In order to broaden the amount of users that can benefit from the design, it is recommended that the software be transformed into a website that any student at RIT can access via the Internet. This will allow NTID students to bring their laptops to the professor’s office and launch the program immediately. NTID students would also be able to use the program for more than one purpose as well such as peer-to-peer communication. The customer is aware of this proposal and did approve the recommended work.

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Concentration Tab

Conversation Box

Quick Keys

Phrase Auto-complete

Text Entry Boxes

Concentration Tab

Conversation Box

Quick Keys

Phrase Auto-complete

Text Entry Boxes

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In order to implement this design into a website, a team of two to three Computer Engineering students would need to create accommodations for posting the code onto the RIT network. There would also be a need for moderate editing of the original code. Additional features could be added to the code that included equation typing and a scratch drawing pad. The project would take approximately 20 weeks to complete. With proper compliance from the Information Technology (IT) group at RIT, this project would require no funding. It would provide endless benefits for the NTID community.

CONCLUSION

The design process utilized by the team led to the successful development of a two-way communication device. The test plan was used to measure the design specifications that were and were not achieved. All of the design specifications were successfully achieved except for the implementation of the suggested phrase feature and the capability to save conversations onto a USB storage device. The customer is satisfied with the design of the device and the capabilities that it provides. Future recommendations for this project have been suggested to the customer and accepted as a potential project.

ACKNOWLEDGMENTS

First and foremost we would like to extend sincere thanks and appreciations to the National Science Foundation for providing funding to make this project possible. We would also like to express our thanks to

our guide and customer Dr. Elizabeth DeBartolo and our second guide Dr. Daniel Phillips. Special thanks also go to the staff and students of the National Technical Institute for the Deaf, NTID, Science and Engineering Support Center. Furthermore, sincere appreciation goes to Kyle Howarth from the Computer Engineering department and Yonathan Tulu from the Electrical Engineering department for their extensive support with the software development of this project. We would also like to express our gratitude to the staff of the Mechanical Engineering department machine shop, especially Dave Hathaway and Steve Kosciol. Lastly we would like to thank our single board computer supplier Emac Inc. for their technical support.

REFERENCES

[1] Two-way communication device team. (2007, Feb. 16). EDGE: Engineering Design Guide and Environment. Available: https://edge.rit.edu/content/P07002/public/Home [2] E. Finster, "Embedded Linux on PC/104," in PC/104 Embedded Solutions, 2002[3] Emac Inc. (2007). EMAC, inc. Equipment Monitor and Control. Available: www.emacinc.com [4] Ituner Networks Corporation (2007, Feb. 16). ITUNER. Available: http://ituner.stores.yahoo.net/index.html [5] QT. (2007). TROLLTECH. Available:www.trolltech.com[6] Java. (2007). Sun Developer Network (SDN). Available:http://www.java.sun.com[7] Pac-Tec Enclosure. PACTEC. Available: www.pactecenclosures.com

Copyright © 2007 by Rochester Institute of Technology