Helping Hand

Pedro Rivera-TorresSrrah AlgheithyAmmar AlmaniAndy DuanThad GurielHao Chen

Objectives

Device receives electronic signal transmitted from signs containing

information

A device that can communicate GPS location relative to the destination

Andy Duan

Purpose Aid vision impaired people by navigating

them around unfamiliar places

Read signs and translate them into an audio output

Andy Duan

Looks like…

Small, portable, handheld device

Braille keypad

Andy Duan

Goals First: Capture GPS data, build

sign communication device, implement

keypad input, and text to speech output

Second: Calculate distance and direction of destination,

connect receiver to microprocessor, and

implement voice recognition input

Third:Implement short range obstacle detection using

sonar

Andy Duan

CPU

1. Long range

2. GPS • Calculate• distance/direction

Sonar• Obstacle finding

Compass

Sonar

GPS

Keypad

VoiceRecognition

Communication Device

Memory1. Map/Position2. Voice signal

Speech Translation

Speaker

Power

Sound signal

Satellite signal

User Input

CommSignal

Andy Duan

Communication

Pertinent building data (room#, building #, etc)

Transmitted from sign, door, or building

Received at user device

Thad Guriel

Communication Flowchart

Transmitter Processor

Sign data input

Memory

Transmitter Receiver

Processor

Human user interface

Thad Guriel

Andy Duan

CommunicationXbee Series 1 RF Tran/Rec module

One way communication

Short distance <10 feet

Power output high, may attenuate

Andy Duan

Communication AlternativeRF Link transmitter/receiver

Less expensive alternative

Noisy

Sonar FlowchartUltrasonic signal transmitted

Ultrasonic signal received

Sonar Processor

Device Processor

Output user interface

Thad Guriel

SonarSimple range finding

Low Power

Short distance <3 meters

Narrow beam width

Thad Guriel

Maxbotix LV series Ultrasonic sensor

High Level Block Diagram

Keypad & Voice Recognition

Input command

Microprocessor Speech Generator

Voice direction

GPS Module

Hao Chen

GPS Module

Latitude and longitude information are read by microprocessor as text

sentences

Dimensions: 1.25 x 1.25 x .35 in (32 x 32 x 9 mm)

3.3 V – 5 V DC @ 65 mA

$39.95 from Jameco

Parallax PMB-648 GPS

Hao Chen

Flowchart for GPS

Set up serial communication at 4800 baud

Attempt to parse NMEA data

Successful?

Yes

Store latitude and longitude

No

Hao Chen

Keypad

12-botton numeric keypad

$6.95 from Jameco

Input numbers 0 to 20, each corresponding to an instruction(see user’s manual)

Press * to initiate voice recognition system

Press # to listen to a list of nearby points of interest

Hao Chen

Flowchart for Keypad

Set all row and column pins to HIGH

Consecutively set column pins 1, 2 and 3 LOW

Any row pins closed (LOW)?

Has it been closed for more than 20 ms?

Yes

Yes

Store key press

No

No(De-bounce)

Hao Chen

Speech Recognition

HM2007 Kit at $114.95 or assembled at $179.95 from Images Scientific Instruments

Can be trained to recognize up to 40 words

Accuracy is 95%

Typically trained as speaker dependent

Technique for speaker independence reduces the number of recognizable words

Hao Chen

Compass Module

Parallax Compass Module 3-Axis HMC5883L

$29.95 from Jameco

2.7 to 6.5 VDC

3-axis magnetoresistive sensor

Only 2 axes will be used to measure magnetic bearing

1 to 2 degrees accuracy

Hao Chen

Flowchart for Compass

Signal for data

Is data ready?

yes

Get X and Y field strengths

Calculate and store angle

No

Hao Chen

Map System flowchart

GPS

•Request location from GPS

Receive

•Microprocessor receives coordinates from GPS

Match

•Microprocessor matches user location to location on map (in memory)

Do instruction

•Microprocessor calculates instruction corresponding to button pressed

Speaker output

•Microprocessor outputs result via speaker system

Pedro Rivera Torres

Map module – User cases

1. Determine location2. Determine closest buildings3. Determine closest doors4. Determine path to building

Pedro Rivera Torres

Map module – User case 1

Determine location

› Use Nearest Neighbor Search (NNS) algorithm › Detect region in which point of grid is› Output to text-to-voice device

Pedro Rivera Torres

Map module – User case 2

Determine closest

buildings

Use NNS to look up points within

a specific radius.

Detect number of buildings nearby

Calculate position of

buildings with respect to user

Pedro Rivera Torres

Map module – User case 3

Determie closest doors

• Use NNS to look up points within a specific radius.

• Detect number of doors nearby

• Calculate position of doors with respect to user

Pedro Rivera Torres

Map module – User case 4Determine

path to building

Use NNS to look up door point on grid of

desired destination/building

Use graph theory to determine shortest

available path

Issue updated commands in a

preset time interval to text-to-voice

device

Pedro Rivera Torres

Software Engineering

Objective: the realization of the functions of the system through

handling different components of the

subsystems

Primarily: Coordinate the output of the GPS and

Xbee to load off the right map from SD card.

Update the

location from

the GPS chip

and be able to

pull out proper

voice files from

SD.

Be able to handle ultrasonic location system.Be able to receive voice commands and reconstruct it to do the same job as keypad commands

Ammar Almani

System HardwareThe criteria to

choose the processor:

Word size: 16 bits

Quantity of input and

output: 6 4

Frequency of input and

output:5Hz, 1000 Hz

Memory Requirements:

external memory

Power Requirement:

battery operated

Ammar Almani

Processor

Why? Low Supply Voltage: 1.8

3.6 V Flexible Clock System: 32

Khz 25 MHz Memory: flash memory up

to 256 KB

MSP 430 F5 172

Ammar Almani

Alternative:

Why? Low operating voltage:

1.8 3.6 V More DMA controlling

and internal ADCs Much more

complicated and more expensive

AT Xmega 256 A3BU

Ammar Almani

Audio Output

SpeakJet TTS 256 Translates ASCII characters into an

audio output speech Requires 5V supply voltage Output connected to headphone jack

Srrah Algheithy

Power

Component Voltage Required

Comm 3.3

Voice Recognition

5 V

Compass 2.7 – 6.5 V

Processor 1.8 – 3.6 V

GPS 3.3 – 5 V

TTS 256 5 V

Srrah Algheithy

Division of LaborTask Thad Hao Srrah Andy Pedro Ammar

GPS hardware Primary Secondary Secondary

GPS software Secondary Primary Secondary

Microprocessor Secondary Secondary Primary

Communication Primary Secondary

Sonar Primary Secondary

Voice recognition

Primary Secondary

Compass Primary Secondary

Power Secondary Primary

Keypad Secondary Primary

Text to Speech Secondary Primary

PCB Primary Primary Primary Primary Secondary Secondary

Srrah Algheithy

Schedule

Srrah Algheithy

Risks and Contingency Plan

User overwriting memory Reverse current from higher voltage

chips PCB GPS Electrocution!

Srrah Algheithy

Budget

Item Quantity price

GPS 1 $40

Voice recognition 1 $115

Compass 1 $30

TTS 256 1 $25

Xbee 2 $25

Xbee processor 1 $10

Sonar 1 $50

Keypad 1 $7

Microprocessor 1 -

Total -

Srrah Algheithy

Questions or Comments ??

Srrah Algheithy