Bluetooth Auto-Silencer

Final Presentation Senior Design II

Our Team

Mike Brokhoff• CPE• Programming

Android Device

Brantley Brokaw• CPE• Programming

microprocessor• Programming

Windows Mobile(R)

Delos McManus• EE• Antenna control/

feedback and embedded layout

Barbara Fountain• EE• Power controls

and embedded layout

Dr. Pan Li Faculty Advisor

• Problem• Solution• Constraints• System Overview• BAS Transmitter• Hardware Testing• Software Overview• Software Testing

o Android Developmento Windows Mobile Development

• Questions

Overview

As cell phones become more common in everyday life, the need for cell phone

etiquette has become even more apparent in certain areas of public life.

Problem

IncomingCall

Use Bluetooth technology to develop a hardware and software combination that

will automatically silence cellphones.

Solution

IncomingCall

Constraints

• Technical

• Practical

Technical Constraints

Name Description

Power Supply Must use 120 VAC.

SoftwareMust operate on the Android version 2.2 as a test base. Further expansions of mobile operating platforms are planned.

Frequency Band Must transmit in a bandwidth between 2.4 and 2.48 GHz in order to comply with the Bluetooth standard.

Software Response Timing

Cannot have a latency longer than 3 seconds.

Transmission Distance The transmitter must have a line-of-sight range of 100 feet without obstructions.

Type Name Description

Economic Cost The transmitter must cost no more than $150

Political Compliance The BAS must not violate the Communication Act of 1934

Practical Constraints

Economic Constraint

The transmitter must cost no more than $150, and application software will be free to all mobile device users.

Component Price

Bluetooth Modem - BlueSMiRF RP-SMA $52.00

2.4GHz Duck Antenna RP-SMA – 4” $3.65

PIC24HJ32GP202 Microcontroller $6.00

PCB Fabrication and Assembly $17.00

Enclosure $1.00

Switches (x2) $1.50

LED (x2) $0.30

Push Button $0.25

Voltage Regulator $2.00

Capacitors (x4) $2.00

Wall Transformer $6.00

Power Connector $ 0.50

Resistors (x4) $0.05

Total $92.25

Economic Constraint (Detailed)

[6 & 7]

Political Constraints

The BAS must not violate the Communications Act of 1934.

[2]

System Overview

“BAS-SD-10-11”

Power Supply

BAS Transmitte

r

Microcontroller

Bluetooth Module

Antenna

BAS Application

Mobile Device

OS

Bluetooth Module

Antenna

BAS Transmitter

• PCB and Packaging Design• PCB Testing

  

Schematic

PCB Design

1.7” x 3”

PCB Assembly

PCB in Enclosure

Hardware Testing

• Mobile Device Power Consumption• PCB Power Quality Testing• PCB PIC24 Signal Verification

  

Android Mobile Device

• Tests done over a 10.5 hour period

Windows Mobile Power Consumption

PCB Power Quality Testing &PIC24 Signal Verification

• An oscilloscope was used, across the C1 capacitor for the 3.3 VDC regulator, to monitor for distortion and DC ripple during transmitter operations.

• The logic analyzer was used to monitor the signal between the    PIC24HJ32GP and the Bluetooth Module to verify for correct signal. transmission.

Start-up/Reset Hardware Communications Testwith USB Logic Analyzer

Transmitter Distance Reset Hardware Communications Test with USB Logic Analyzer

Distance Testing

Low Power without Antenna

High Power without Antenna

Low Power withAntenna

High Power with Antenna

Android Platform 35 ft. 160 ft. 65 ft. 250+ ft.

Windows Mobile 6 30 ft. 140 ft. 50 ft. 150 ft.

Software Overview

• FSM• Software Testing

o Android Development  o Windows Mobile Development

 

Software FSM

Software Testing

• Android Application• Windows Application

Android Application

• Emulator  o Creating Graphical User Interface o Control Ringer Stateo System Timer 

 • Mobile Device Deployment

o Turn On/Off Bluetooth moduleo Control discoveryo Read devices being discoveredo Response Timing

Control Ringer and Timer

Scan and Recognize Bluetooth Signature

Android Menu Testing

Android Full System Test

Android Software Testing

Application can:

• Detect BAS signature• Silence/Vibrate Ringer when BAS signature detected• Runs check every 12 seconds when BAS sig. not found• Runs check every 15 minutes when BAS sig. found• User cannot change ringer while in "Silent Zone"• Rechecks for "Silent Zone" when attempting to change

ringer state• Restores ringer when BAS no longer detected• Run for several days• Go between background and foreground• Operate while other programs are running in the foreground• Operate while in a phone call

Latency Testing

Average Delay 2.3 seconds

Expected Delay 3.0 seconds

Percent Error -24.44%

Windows Mobile

• Windows Mobile vs. Android• GUI • Full System Test• Latency Testing

Windows Mobile vs. Android Development Pros and Cons

Pros Cons

Android Platform(Motorola Droid)

-API is easy to implement-Easy access and control of Hardware elements-Faster-Easy to use debugging process

-GUI Development

Windows Mobile 6(HTC Touch)

-GUI is easy to implement-Easy to use debugging process

-Very difficult to access Hardware elements(.dll import process)-Very slow-Complicated API

Windows Application

• Emulator  o Creating Graphical User Interface o System Timer 

 • Mobile Device Deployment

o Turn On/Off Bluetooth moduleo Perform a Bluetooth device Scano Read devices being discoveredo Control Ringer

GUI Windows Mobile

Disabled Enabled beforeDevice is Discovered

Enabled and Discovered

Windows Mobile 6 Full System Test

Latency TestingWindows Mobile 

Average Delay 13.81 seconds

Expected Delay 3.0 seconds

Percent Error 360.22%

References

[1] Wikipedia, “Mobile phone,” Wikipedia. [Online]. Available:  http://en.wikipedia.org/wiki/Mobile_phone. [Accessed Aug. 31, 2010].[2] Federal Communications Commission, “Sale or Use of Transmitters Designed to Prevent, Jam or Interfere with Cell Phone Communications is Prohibited in the United States,” Federal Communications Commission, July 27,2005. [Online]. Available: http://www.fcc.gov/eb/Public_Notices/DA-05-1776A1.html. [Accessed: Aug. 31, 2010].  [3] Bluetooth SIG, “About The Bluetooth SIG,” Bluetooth SIG. [Online]. Available: http://www.bluetooth.com/English/SIG/Pages/default.aspx. [Accessed: Aug. 31, 2010].  [4] Locale, “Release Notes,” Locale 2010. [Online]. Available: http://www.twofortyfouram.com   [Accessed: Aug. 29, 2010].  [5] J. Griffin, “How does Q-Zone work?,” Bluelinx, 2010. [Online]. Available: http://www.bluelinx.com/qzonehow.html. [Accessed: Aug. 31, 2010].  [6] Screaming Circuits. [Online]. Available: http://www.screamingcircuits.com/Order/Quote [Accessed: Apr. 14, 2011].  [7] PCBex Corporation. [Online]. Available: http://www.pcbex.com/  [Accessed: Apr. 14, 2011].