Eye Can Hear You
Michael Cooke, David Griffen, Whitney Keith,
Edward Romero
School of Electrical Engineering and Computer
Science, University of Central Florida, Orlando,
Florida, 32816-2450
Abstract — An audio switching network composed of
wireless headphones and television audio is implemented to
enhance mobility and selection in a multiple audio
application. Users can wirelessly “lock-in” audio from a
television within their line of sight through a button press.
Additional features include RSSI based triangulation that is
able to track headphones within a region and graphically
display the location on a tablet through an Android
application. The graphical user interface (GUI) will display
headphone registration, restaurant setup and an emergency
headphone kill switch. The usage of four different wireless
technology applications, 900MHz Radio Frequency (RF),
2.4GHz RF XBees, RF Bluetooth protocol and Infrared Pulse
Width Modulation (PWM), produces a unique and
challenging project.
Index Terms — Pulse width modulation, Infrared
detectors, audio systems, radio frequency, headphones,
wireless communication, graphical user interfaces.
determined by RF triangulation. The location will be
wirelessly transmitted to the tablet for the user to monitor.
The application will also implement an enable/disable
switch that allows the tablet user to initiate/terminate
audio transmission to the headphones.
II. SYSTEM CONFIGURATION
The system is implemented in a sports bar like
environment with multiple televisions for customer
entertainment. At several sports bars one television
dominates the audio of the room and customers are
subjected to viewing other televisions without the
corresponding audio. ECHY allows multiple users to
wirelessly choose which television to listen to.
Fig. 1.
I. INTRODUCTION
Developed and designed to enhance a mobile audio
environment for restaurant customers, Eye Can Hear You
(ECHY) allows users to lock in audio from one television
within a network.. The project provides customers with a
mobile audio experience as well as delivering quality
sound. A main board was developed to control the
subsystems of the project such as audio switching, audio
streaming, and a communication bus to the application
module. A wireless headphone to television identification
system is designed to send a custom encrypted message
using infrared LEDs from a headphone to a detector
located on a television. The detector decodes the IR
message and communicates the decrypted message to the
master board.
The master board also receives all
television audio within the network and streams the audio
to a specific headphone depending on the message
received from the detectors.
Security of the headphones is enforced with an Android
application on a tablet which is used to register and
monitor the headsets. Location of the headphones will be
Project system layout
The triangulation system as seen in Figure 1 shows four
nodes, each located at a corner of the room. The master
board will be wired straight into the modules from each
television and television audio. The tablet is able to
communicate to the master board and each headphone via
Bluetooth and Xbees.
II. COMPONENTS
A. Microcontrollers
The three microcontrollers used in this project are the
Stellaris, MSP430, and Atmega328.
The particular Stellaris chosen is the Texas Instruments
LM3S8962. The Stellaris is used on the master board
since it is able to handle vast amount of General Purpose
Input Output pins (GPIO) for multiple system
communication. All the subsystems together take up 25
GPIO pins from the master board which satisfies the
original reason of choosing this processor. The subsystems
controlled by the board are the sound switching, the audio
enable/disable switch, and the transmission of the audio.
The MSP430g2231 is implemented on the headphone
and the IR detector boards. The MSP430 was chosen due
to its low power consumption, input interrupts, PWM
output, capture and compare registers, and 8 GPIO pins.
The ATmega328 is used in the RF triangulation
subsystem. The Atmega was chosen for its high flash
memory capacity, multiple serial data ports capability, and
high precision in arithmetic operations.
B. Wireless Technologies
The wireless technologies used in this project are
900MHz IEEE 802.11, 2.4GHZ IEEE 802.15.4, Bluetooth
supporting SPP/Dun and HCI, and 940nm Infrared.
The audio for the headphones will be transmitted
through the unlicensed 900MHz frequency spectrum. The
master board will use the Linx Technologies (TXM-900HP3-PPO) transmitter module, while the headphones will
use the (RXM-900-HP3-PPO) receiver module. The
compatible modules transfer audio via a frequency
modulated (FM) signal at long distances exceeding 50
feet.
The 2.4GHz module used is the Xbee S1. This module
is used in the Radio Signal Strength Indication (RSSI)
based triangulation subsystem. The RSSI is measured
from each of the Xbee modules (nodes) and converted into
a distance constant unique to that measurement. The
triangulation algorithm used for GPS is then used to figure
the coordinates of each of the headphones in respect to the
origin at one of the corners.
The Bluetooth is used to transmit the enable/desable
commands to the master board. The RN-41 Bluetooth
module mounted on the master board was chosen for its
embedded Bluetooth stacks and the auto discovery. The
tablet and module are Bluetooth compatible.
The IR is used in the audio switching and headphone
identification. The IR PWM signal was chosen because
the line of sight propagation of the LED and the PWM
ability to send a unique identification at a reasonable
distance.
to each headphone when a button is pressed. A detector
board located on each television contains an IR sensor to
capture the IR PWM signal sent from each headphone.
The captured signal is decoded and compared by the
MSP430 to determine which headphone is viewing the
television. The MSP430 communicates the specific
headphone ID to the master board for sound switching.
B. Audio Switching and Transceiving
Once the particular headphone ID has been received by
the master board, the Stellaris microcontroller unit (MCU)
processes the ID for audio switching. Located on the
master board are two multiplexers (MUX), one per
headphone. Each multiplexer has audio from each
television as inputs. The Stellaris uses the multiplexers to
re-route the audio to the desired headphone.
C. Radio Frequency Triangulation
The headphone localization system consists of RSSI
based triangulation. Each headphone is able to find its
own location by using the four Xbee modules localized in
each corner of the system. The idea is that the headphone
uses the Atmega328 to talk to the Xbee module via serial
communication. It tells the Xbee to call for every Xbee in
range and the Xbee returns each Xbee’s unique ID,
address, and RSSI measured to the headphone. The
atmega328 takes this data five times, and calculates an
average. This average is then compared with a data table
containing RSSI to distance conversions from each Xbee.
Three circle intersection geometry is then used to figure
out the (x,y,z) coordinates of each headphone in reference
to the origin being one of the corners.
D. Graphical User Interface
The graphical user interface allows staff to register and
locate headphone users, create room dimensions and view
headphone status. The GUI communicates with the master
board and the headphone Xbees to enable or disable audio
to the headphones and retrieve headphone location data
respectively.
III. SUBSYSTEMS
IV. HARDWARE
The project consists of four subsystems, headphone-totelevision identification, audio switching and transceiving,
RF triangulation, and a graphic use interface (GUI).
A. Headphone
The headphones were designed to ensure wireless audio
compatibility between the receiver and transmitter instead
of purchasing and modifying wireless headphone
hardware. The headphone hardware consist of two printed
circuit boards (PCB) mounted one on top of the other. The
first PCB controls audio receiving, audio buffering,
volume, and the infrared PWM signal output. The second
PCB calculates the position of the headset, and then
A. Headphone-to-Television Identification
This subsystem is responsible for identifying which
headphone user is viewing a particular television within a
network. The designed wireless headphones include an
array of IR LEDs, used to transmit an 8 bit PWM unique
transmits its position to the tablet. The PCBs are mounted
on the band of the headphone to ensure line of sight
infrared transmission.
The television audio for the headphone is received on a
900MHz radio frequency using Linx Technologies RF
module (RXM-900-HP3-PPO). The module can receive
on 9 different RF channels within 900-922 MHz. To
utilize the multitude of channels, a DIP switch was
connected to the channel select lines. The headphone
receiver and master board transmitter must be on the same
channel as in Figure 2. A 50Ω quarter wave antenna with
a RP-SMA connector compliant with the FCC’s Part 15
rule was chosen. The antenna is placed on a PCB ground
plane to reduce noise. The module was ideal for this
application since it handles an FM to AM signal
conversion without external components, simplifying the
output of the module to an audio out pin.
Fig. 2.
Detector circuit to decode headphone infrared PWM.
Fig. 3.
Audio amplifying and buffer circuit.
For headphone-to-television identification a 2x3 array
of IR LEDs are located on the edge of the PCB. The IR
LEDs (TAL6200) operate at a peak wavelength of 940nm
with a half angle intensity of 17°. Since the LEDs have a
small angle of light intensity the direction of the signal is
more linear. This focuses the user’s line of sight to a
particular television. A button on the side of the
headphone triggers the LEDs to output a PWM signal. The
MSP430 in this application is used to receive a button
press and output a unique PWM signal at carrier frequency
of 38 KHz using the Sub-Main clock. Previously the
design included using a 555Timer to blink the LEDs at 38
KHz, however using the MSP430 instead decreases
hardware, decreases delay, and is more cost efficient.
Since the power supply to the MSP430g2231 and the
RF receiver operate on a low power of 3.3V, a 3.3 voltage
regulator (LP2950-50-33LPRE3) is used to step down the
voltage. While a 9 V is used for the voltage divider, the
MSP430 and RF receiver will run off 5 V from the RF
triangulation board on top of the headphone PCB. The 5V
will still be regulated by the 3.3V regulator. For circuit
connections refer to Figure 4.
After the audio is outputted from the RF module it is
buffered to clean up the signal and lower the impedance
into the speakers. The audio is first passed through a dual
gang audio taper potentiometer, which is used to increase
and decrease the volume. The audio is handed to an
operational amplifier (Op-Amp) (TL082). The Op-Amp
circuit is based off a buffer and a modified 2 nd order band
pass filter circuit as in Figure 3. To power the Op-Amp, a
+4.5 and -4.5 voltage supply is necessary, therefore the 9V
battery was split using a voltage divider. Lastly, the audio
is sent to the 8 ohm speakers for the user to enjoy.
Fig. 4.
Headphone IR emitter circuit
B. Infrared Detector
To identify a headphone is viewing a particular
television; a detector board located on top of each
television, receives and decodes IR signals. A vector
board on each television includes a 9V power supply, 3.3
voltage regulator, IR detector module, MSP430g2231 and
2 red LEDs. The detector module (TOP32338) internally
filters IR light at 38 KHz and decodes best at a wavelength
of 940 nm. To ensure compatibility, the IR LEDs and
detector module were chosen from the same manufacturer.
When an infrared signal is detected the module outputs
low, otherwise it outputs high. For connections refer to
Figure 5. The module output is connected to the MSP430
which processes the signal into an 8 bit value to identify
the headphones currently viewing the television.
The MSP430 then communicates with the Stellaris
located on the master board through 4 independent lines.
A Ready to Send (RTS) signal is sent to the Stellaris once
a headphone ID is matched to detected IR signal. When
the Stellaris is ready to receive the data lines, it sends a
Clear to Send (CTS) signal to the MSP430. The MSP430
then sets Line0 and Line1 which represent the bits for the
headphones identified. For example, headphone 1 ID is
Line0=1 and Line1=0. These values inputted to the
Stellaris will be processed to determine the television
audio transmitted to the headphones.
Fig. 5.
televisions is split into the inputs of each MUX. The select
lines of each MUX are connected to the Stellaris. When
the Stellaris receives the data from the IR detector boards,
the microcontroller will output a high or low on the
selector lines. In this project, the select line values 01, 10
or 11 represent audio from televisions 1, 2 or 3
respectively. The output of the MUX is connected to the
data line of the RF transmitter. A 6 position DIP switch is
used to control the frequency channels of the two RF
transmitters. The first 3 positions on the switch are to
control the RF transmitter’s channel select for headphone
1 and the last 3 positions for headphone 2. The same
antenna used for the RF receivers are used for the RF
transmitters. To reduce noise in audio transmission the
entire PCB is placed on a ground plane.
The communication between the Stellaris and the
Bluetooth module requires one set of UART pins. A
bilateral communication with the tablet is possible by this
module. The interface of the master board and the tablet
allows the user to enable/disable headphone audio. This
switching mechanism lets the Stellaris know when to
enable or disable the audio through the MUXs.
D. Radio Frequency Triangulation
The system is divided into two different circuit layouts
that are able to communicate with each other. This allows
them to calculate the exact position of each headphone in
a coordinate system.
The first circuit layout is the same for the four modules
at each corner. This module consists of a powered on
Xbee with a unique ID. The module participates as a
beacon in which the headphone will communicate and
figure out its RSSI in between the two. The schematic is
shown in Figure 6.
Television Detector Circuit
C. Master board
The main function of the master board is to control the
transmitted television audio to each headphone. There are
two 4:1 MUXs on the board, one for each headphone’s
audio switching. The master board receives audio from
each television through RCA jacks. The sound from the
Fig. 6.
Corner Node Xbee Circuit
The second circuit layout consist of an Xbee module, an
atmega328, two LEDs for testing, LM7805, LD1085v33,
and a 16MHz clock. The Xbee is based on a power range
of 2.8 to 3.4V in comparison to the atmega328 which
utilizes 5V. The atmega328 is able to detect when a lower
voltage component is plugged in so it automatically
lowers the power supply to it. So no potentiometer is
needed to lower the serial data coming from the atmega to
the Xbee. The corresponding circuit is shown Figure 7.
Fig. 7.
Headphone Xbee Triangulation circuit
headphone ID, and the program automatically determines
the correct PWM signal to output through the LEDs.
B. MSP430 Detector
The detector software is also programmed on the
MSP430g2231 in C language. This program receives an
input on P1.2 from the detector module as a high (no IR
signal detected) or low (IR signal detected). The input pin
is initially set as a TimerA capture pin on the falling edge.
This will capture the clock time when the Start bit begins.
P1.2 will be set to capture on the next rising edge. The
difference of this clock time and the previous clock time
measures the Start bits ON time.[1] The Start time is
checked to verify it is within a 5% range of 40ms. If true,
the program determines the time between the following
rising edges to decode the detected signal into 8 bits. A 0
or 1 bit is determined by comparing the time detected to
the average ON/OFF time of both bits. If the calculated
time is greater than the average the bit is 1. If less than
average the bit is 0. Once the 8 bit value is reconstructed
from the signal, it is compared to all headphone IDs. For a
pictorial view refer to Figure 8.
V. SOFTWARE
This project involves a variety of embedded
programming and GUI. This entails creating four different
programs for eight microcontrollers. The breakdown of
the microcontrollers is 5 MSP430g2221, 2 Atmega328
and a Stellaris LM3S8962.
A. MSP430 Emitter
The emitter software for the headphone is programmed
on the MSP430g2231 in C language. The MSP430 was
debugged using the LaunchPad development board
provided by Texas Instruments. The MSP430 input pin
(P1.0) is connected to a button with a high to low interrupt
enabled. Once pressed, an interrupt flag occurs, triggering
an LED array emission on the output pin (P1.4). The IR
LEDs must blink around 38KHz, for the IR detector on the
television to recognize the signal. This is achieved by
using the sub-main clock (SMCLK) function for P1.4,
operating at 37.5 KHz.
The LEDs on the headphones transmit a Start bit
followed by an 8 bit identification signal. For example,
headphone 1 would transmit 0000 0001 where headphone
2 would transmit 0000 0010. Each bit is represented by an
ON/OFF timing of the LED. For example, an ON bit is
represented by the LED remaining ON for 25ms followed
by it remaining OFF for 25ms. The OFF bit has an
ON/OFF timing of 40ms/25ms respectively. Lastly, the
Start bit has an ON/OFF timing of 50ms/25ms. This
program is created for the user to input any 8 bit
Fig. 8.
The IR emitter signal for headphone 1 is represented
on the top and corresponding detector output to the
MSP430 is shown on the bottom.
Once a match occurs the detector board will
communicate with the Stellaris through RTS, CTS and 2
data lines.
C. Stellaris
The software for the Stellaris was programmed in C
language. Its programming was tested on the EKSLM3S8962 development board. The first step in the
Stellaris program is to wait for a command from the tablet
to set the enable line high for the MUXs. This is
accomplished through the Bluetooth module connected to
the UART pins on the Stellaris.
To load the program on the Stellaris, a 20 pin ribbon
cable connects the master board to the development board.
The 20 pin ribbon cable is connected to the Stellaris’s
JTAG pins that allows for programming of the surface
mounted device.
Once the first headphone is registered, the enable line to
the MUX goes high. This is accomplished by the tablet
sending a set of hexadecimal values to the Stellaris. An
example of the value sent is FF, which means to enable
headphone 1. The Stellaris also receives a disable
command from the Bluetooth module changing the enable
line to the particular headphone’s MUX low.
After the enable line goes high, the main loop initiates
the audio switching subsystem to start. After the detector
registers a headphone, it sends a high RTS line to the
Stellaris. The Stellaris will read the RTS pin and if high,
the Stellaris sets the CTS line high back to the detector
board, which will allow the transmission of the headphone
IDs. Once the headphone ID is read in, the Stellaris
outputs the select lines to the MUX’s. For example, if
headphone 1 looks at television 2, the Stellaris will output
a 10 to the MUX’s select lines for headphone 1. The audio
is then automatically transmitted to the headphones from
the 900MHz transmitters.
D. Triangulation System
The software part of the triangulation system is located
only at the headphone board. The Xbee modules that are
located at each corner do have to be programmed to have a
unique ID and to share the same baud rate and general
destination address but since this can be found rather
easily in [3] so we will not discuss it. First all the Xbees
have their unique IDs programmed; in this case we name
each Xbee at each corner MX0, MX1, MX2, MX3
respectively to their positions in the square. After doing so
the programming of the corner modules was done.
The headphone part of the triangulation has an
Atmega328 micro-controller that runs the algorithm. The
Atmega328 has the Xbee get into API mode through the
serial line. Then it calls a “ATND” commands which
returns the identifiers plus the RSSI and other
characteristics of all other XBees in range. Once this
information is read each RSSI from each corner is read.
As said before five samples are taken to minimize outliers.
At first there is no way to convert this RSSI data to
distance values. Training is done in which at known
distances values of RSSI are measured and recorded. All
these values are compiled into a table and are hard coded
to the program. A different training set has to be recorded
for each different venue. Since now the software has a
reference table and the unknown distance corresponding to
the measured RSSI values then a closest match algorithm
is used to find the minimum distance from a known RSSI
value to the unknown one.
The distances collected are use as radii to form circles
by using each of the corners as centers of each circle.
Circle equations are built and the intersection between
three consecutive circles is measured by using simple
algebra and geometry. The (x,y,z) values are collected
from each of the three, and since there are four possible
measurements, a simple average is used between all the x,
y, and z coordinates to come up with only one point. This
point is then sent via 2.4 GHz from the XBee to the
application being run on the tablet. The tablet needed a
way to receive data from the Xbee without interference by
the other Xbees. An encrypted string was used with the
following layout.
$Name,x-value,y-value^
$ = begin of message received flag
Name = H + the number of the headphone. Ex: H1
x-value = x coordinate in meters
y-value = y coordinate in meters
^ = end of message received flag
E. Graphical User Interface
To maintain security of the headsets, a GUI is
implemented. The main functions of this interface are to
register customers who use the headsets and to track the
location of each headset on a custom-built map. To best
maintain mobility and the wireless function of this project,
the GUI must be designed to run on a mobile device. For
this project, the interface is implemented on the Toshiba
Thrive, a tablet device that runs the Android Operating
System (OS).
The Toshiba Thrive is equipped with a dual-core
processor to handle any application with heavy processing
power. The tablet also comes with USB ports and a
Bluetooth module to allow different types of
communication the group will be utilizing. The tablet is
10.1 inches diagonally, allowing for a comfortably large
screen to read and interact with the GUI.
Google’s Android uses Java, an object-oriented
programming language, along with its own extended
libraries. The libraries are provided online on Google’s
developer website along with examples and the software
development kit (SDK) necessary for application
development. This operating system was chosen due to the
extensive documentation and familiarity of the
programming language with the group members.[2]
The main features implemented in the Android
application are Drag-and-Drop for setting up the map,
Shared Preferences to indefinitely store restaurant
information (can only be destroyed upon rewriting or
uninstallation), an SQLite database to store users and their
registration info, a Bluetooth service to connect to the
Stellaris master board, and connection to the USB port to
communicate to the XBee triangulation system.
Fig 9.
Google IOIO for Android
Besides the tablet, there are two pieces of hardware that
interact with the GUI and communicate information back
and forth. For the Stellaris board to receive “turn on” and
“kill audio” commands for each headset, a Bluetooth
Module (RN41) is used to communicate with the Tablet’s
on board Bluetooth. This communication does not require
heavy listening and will be used as a “service,” which
allows a connection to remain while having low
processing power. For the tablet to receive triangulation
data from the XBee setup, the tablet uses its USB port to
communicate with SparkFun’s Google IOIO for Android
device.
Fig. 10. Software flowchart for Android application’s GUI.
Google IOIO is used to translate between Android’s
Debug Bridge (ADB) interface and a microcontroller’s
Serial Port Protocol (SPP). The IOIO device contains 48
Input/Output pins for a high number of peripherals to be
attached; pins 4 and 5 will be used for this project,
transferring data to and from the XBee module that
communicates with the rest of the triangulation system. A
representation of the Google IOIO device is shown in
Figure 9.
There are seven activities that make up the GUI for user
interaction; the functions are best visualized in Figure 10.
The system begins with MainAppActivity, where the
user has a choice of connecting to the system, setting up
the restaurant’s information, or connecting to an About Us
page which describes the project in more detail.
The setup for the restaurant is split into two different
activities (SetupMapActivity and SetupMapActivity2), the
first one takes in the name, dimension type, dimensions,
number of headphones and number of tables the system
uses. This information is then stored in the application’s
Shared Preferences, a storage area that exists so long as
the application is not uninstalled. The second activity
utilizes the Drag-and-Drop method by allowing the user to
place a number of tables onto a square map. Once all
tables are set, the map and tables are captured onto a
Bitmap, each table is named, and both the tables and map
are saved as a .PNG file for later use. Once the setup is
complete, the user is redirected to the MainAppActivity.
Once the map has been setup, the Connect button
(previously disabled) is enabled and the user can connect
to the system. Pressing the “Connect” button opens up a
Bluetooth Connection to the Bluetooth module (RN41)
and begins a service that runs alongside the application;
allowing the connection to remain without being processor
heavy. Once connection is confirmed, MapScreenActivity
is launched and opens up connection to the Google IOIO
device and begins communication with the triangulation
system (receiving and displaying positions of the
headsets). A String is given to the tablet that represents
each headset’s position; this was depicted in software
section of triangulation. Each headset is drawn and
redrawn using Java’s Canvas method, which can draw
images quickly without lagging.
At the MapScreenActivity, the user has the option to
register new customers or select headsets the restaurant is
using. Registering new customers sends the user to the
RegUserActivity, where information such as customer
name, table number they’re sitting at, headphone being
assigned, credit card number and phone number are
recorded. Once the information has been updated, the
system stores it into a SQLite database along with the time
the registration occurred. A command is issued to “turn
on” the particular headset to the Stellaris board through
the Bluetooth service connection.
Selecting a headset sends the user to the
HeadphoneStatusActivity, which displays the information
associated with it. If the headset is in use and is registered
to a customer, it pulls information from the SQLite
database on that particular headset and displays that
customer’s information (including how long the customer
has been using the headset). The user has the option to kill
the audio of that particular headset, which usually means
the customer is finished and the headset is being turned in.
Once selected, a kill command is sent to through the
Bluetooth service to the Stellaris board.
If at any point on the MapScreenActivity, a headset that
is registered leaves the boundaries of the sports bar, a
security flag will be set and the SecurityUserActivity will
be brought to the front. From here, the same information
as the HeadphoneStatusActivity is displayed along with
the customer’s credit card number and phone number. The
establishment can deal with theft however they want from
this point forward. This automatically sends the kill audio
command to the Stellaris via the Bluetooth service.
David Griffen is a 22 year old Computer
Engineering major graduating in August
2012. He is currently interning at Campus
Crusade for Christ World Headquarters
working with the Web Publishing Team,
maintaining their Oracle Stellent system
and their public Cru.org website. After graduation he is
earning his Masters degree in Computer Engineering at
the University of Central Florida with a focus on Software
Design and Machine Learning.
Whitney Keith is a 22 year old
Electrical
Engineering
major
graduating in August 2012. In 2010
she was a research assistant under Dr.
Brian Moore in simulating the effects
of rocket exhaust on cratering. After
graduation, she accepted an Electrical and Electronic
System Engineering position with Ford Motor Company
in Dearborn Michigan.
Edward Alfonso Romero Guerrero is a
22 year old Electrical & Computer
Engineering major graduating in August
2012. Currently he is the lab manager of
Aerolab electronic laboratory in the
MMAE department at the University of
Central Florida.
VII.CONCLUSION
The Eye Can Hear You engineering project was
hardware and software intensive. It implemented wireless
audio transmission and filtering, RF triangulation, custom
IR PWM emission and detection, Bluetooth
communication, and an extensive Android application for
headphone control and location display. The project
consists of seven individual PCBs and three vector boards
to guarantee component connections and accurate
operation. ECHY is a television audio switching network
for wireless headphones including headphone tracking,
audio control and registration. Future applications could
extend from restaurants to gymnasiums or industrial
applications were several viewers need to switch between
the audio of multiple televisions.
ACKNOWLEDGEMENT
The authors wish to acknowledge the assistance and
support of Dr. Larry Chew in providing essential parts for
this project as well as Dr. Samuel Richie for guidance. We
also would like to acknowledge our Review Committee:
Dr. Zakhia Abichar, Arup Guha, Dr. Vikram Kapoor and
Dr. Mark Llewellyn for their time and support. We would
like to acknowledge Texas Instruments contribution to the
project in sampling of parts and providing development
boards.
BIOGRAPHY
Michael Cooke is a 22 year old Electrical
Engineering major graduating August
2012. He has been active in Theta Tau
Professional Engineering Fraternity,
American Society of Engineering
Education (ASEE), Future Technical
Communicators (FTC) and Student Panel
for Engineering and Computer Science
(SPECS). In 2010 he worked as a research assistant under
Dr. Ron Eaglin in database creation.
REFERENCES
[1]
[2]
[3]
Buccini, Mark and Stefan Schauer. Decode TV IR
Remote Control Signals Using Timer_A3.
September 2001. Document.
Google Developer: Android API Guides,
<https://www.sparkfun.com/products/10748>
“Xbee radios Wireless arduino programming/serial
link”.
May,
2011.
<http://www.ladyada.net/make/xbee/arduino.htm
>