Classroom CollaboratorBrandon Reagen, Matthew Ng, Runfeng Chen, Robert Connelly

Faculty Advisor: Prof. Tessier

Department of Electrical and Computer Engineering

ECE 415/ECE 416 – SENIOR DESIGN PROJECT 2012College of Engineering - University of Massachusetts Amherst

SDP 12

System Block Diagram

Project DescriptionBy creating an Android application, we intend to provide a two-way communication medium, not only for instructors and students, but also for students to fellow students. Our application aims to periodically collect information about the students in the class. Our device will validate a student’s identity and establish their presence in the classroom. To validate a student’s identity, a RFID reader will be used to pull unique information from the Radio Frequency tag in a student’s UCARD. Presence in the classroom will be verified via a password received as a broadcast Bluetooth message of limited range.

Group Picture

Hardware Design

User Interface

The interface provides an easy navigation of the application’s features including class chat room, class slides, notes, and popular sites.

Motivation

The hardware verifies the identity and location of the student. An RFID reader checks the students ID while a Bluetooth module receives a localized password.

• Log in Authenticate presence and identity

• Chat RoomCommunicate ideas and points of

confusion

• Popular SitesShare useful online resources

• Download Class SlidesPersonal copy of class materials

• Class NotesTake notes on each slide

System Analysis

Bluetooth Connection Range Analysis

Activity Component Current (mA) Power consumption (mW)

Total Power Consumption (mW)

Time Duration (hr)

Bluetooth Connected

Bluetooth 39.7 227.08 642.35 15.6

RFID 11.1 63.49

USB Shield 21.3 121.84

Arduino 40.2 229.94

Bluetooth Idle

Bluetooth 32.4 185.33 592.59 16.9

RFID 10.8 61.78

USB Shield 20.2 115.54

Arduino 40.2 229.94

Power Consumption

Student attend multiple class classes every day by developing a power efficient device we can ensure users will not worry about dead batteries. The following is a table characterizes the power consumption analysis for each component of our security system. This device will have a life time span of 15 hours.

To gain access to the server students must continuously receive a password via Bluetooth. To ensure within the classroom receive this password we analyzed the range of our connection. The graph below display the average connection time between two devices as we vary the range.

Password Strength Analysis

Every 30 seconds an eight byte, randomly generated password is broadcast to students. The password is re-generated for each transmission. This password is supplied to the server to gain access. Below is the formula to determine password strength.

Our eight byte randomly generated password has a strength of 47.63 bits.

Components Quantity Price ($)

Android Tablets 2 110.95

Bluetooth Module 2 64.95

Arduino Uno Board 2 29.95 (free)

RFID reader 1 12.50

USB Host Shield 2 24.95

Total Cost: $414.20

Project Cost

Android Application

Server Design

The server provides all the back end functionality for the system. It tracks all users, periodically checking and banning users for missed passwords. It collects popular sites suggested by students, and shares them with others in the class. A chat room is also hosted here for students to collaborate on points of confusion. Finally, it makes the slides available for download on each students device.

The class slides and popular website feature of the application are pictured above. The android application provides the interface between the server and security hardware. By providing an easy to use interface we hope to provide user with an enjoyable and enhanced learning experience.

• Chat Room• Access Control• Popular Sites

• Hosts Class Slides