WIRELESS CONTEXTUAL INFORMATION ELECTRONIC

SYSTEM FOR PEOPLE WITH DISABILITIES

S. Borromeo, C. Rodriguez-Sánchez, J. A. Hernández-Tamames and N. Malpica

Electronics Engineering Department, Medical Imaging Group, Rey Juan Carlos University

C/Tulipán S/n Móstoles, Madrid, Spain

Keywords: Wireless Electronics, ICT for people with disabilities, Disability Discrimination, Bioengineering, Pervasive

Computing, Bluetooth.

Abstract In this work we present a prototype of two electronic devices for providing relevant information to people

with disabilities, such as the blind, deaf or elderly, in public environments (railway stations, airports, etc).

Usually, this kind of collectivities is discriminated in terms of information access. Most of the public

information is in text panels, monitors or traffic signals. The rights of these people are easily forgotten. With

this work we try to make an effort in this direction facilitating the information access to these groups. In

order to avoid them feeling different we try to adapt the transmission to standard portable devices. We based

the work on bluetooth technology. Concerned by costs, in order to popularize this technology, our designs

use off-the-shelf components. We also propose a new device to avoid the proximity marketing spam so that

these people don’t suffer its consequences.

1 INTRODUCTION

Lately, there is an increasing interest in ICT for

People with disabilities. (Busby, G. Whitehouse, D.

1997), (Busby, G. 1997) (Blanchard, S.M.

Rohrbach, R.P. 2000).

Blind, deaf and elderly people are usually

discriminated in public environments, such as

railway stations or commercial centres, when real

time information about transport timetables,

commercial advices or security warnings is being

emitted (Karim, N.A. Nwagboso, C., 2004).

Something similar occurs in signalling for urban

purposes. This collectivity can not be informed

instantaneously and they are unaware about eventual

dangerous situations for them such as holes or wet

pavements. Signaletics is a discipline susceptible to

be completed with new developments based on

wireless beacons. In this work we present a general

purpose prototype of sender and receiver to be used

as wireless beacons based on an off-the-shelf

Bluetooth chipset. In fact, the receiver can be

substituted by Bluetooth-equipped commercial

mobile phones or PDAs.

In this sense, some airports and railway stations

have arranged systems based on sms mobile

technology. People with disabilities have to reach a

special information desk to borrow a mobile phone

explaining her destination and the rest of the travel

information. When the transport is close to

departure, one sms is sent to the mobile. However,

people can read signals, can watch tv monitors or, in

some cases but less now, can listen to advices and

messages.

We propose to incorporate wireless beacons to

the information system of monitors or panels for

sending relevant information to the portable devices.

In this paper we only present the electronic

devices needed for a basic communication. One of

our major objectives is the development of low-cost,

low-consumption and small devices using off-the-

shelf electronic modules.

2 SYSTEM ARCHITECTURE

The system consists of a sender device and a

receiver device. Both can exchange information

through the Bluetooth protocol. Moreover, the

receiver can send the information to the mobile or to

the PDA of the disabled user.

Figure 1 shows the basic modules of the

architecture. A receiver beacon could suffice, and is

182

Borromeo S., Rodriguez-Sánchez C., A. Hernández-Tamames J. and Malpica N. (2008).

WIRELESS CONTEXTUAL INFORMATION ELECTRONIC SYSTEM FOR PEOPLE WITH DISABILITIES.

In Proceedings of the First International Conference on Biomedical Electronics and Devices, pages 182-185

DOI: 10.5220/0001053201820185

 SciTePress

cheaper than standard portable devices such as

mobile phones or PDA’s.

Figure 1: Basic components in the system.

The sender Beacon is equivalent to the monitor

or panel information system in airports o railway

stations. It is also equivalent to a warning

advertisement or traffic signal for people in any

street or in any commercial centre.

It stores relevant information messages in

different data formats (audio, text or image) and

transmits them to the receiver beacon.

Receiver beacon consists of a PIC

microcontroller, a Bluetooth module and a LCD for

showing text messages.

The receiver beacon communicates with the

sender beacon via the Bluetooth protocol and,

optionally, sends complex messages, in audio or

image data format, to the portable device when it is

present.

Actually, the receiver beacon could be optional

whenever a portable device is available. The

messages can be sent by the sender beacon to the

portable devices directly, but, we have found several

advantages to incorporating this small device.

Firstly, as mentioned above, it is cheaper than a

mobile phone or PDA. In the case of deaf or elderly

users, the receiver beacon is enough for receiving

and viewing information. These users don’t need to

afford an expensive portable device for taking

advantage of this technology, something especially

interesting in developing countries. In the case of

blind users, audio reproduction is currently being

added to the beacon.

Secondly, the receiver beacon, when used

together with a standard portable device, can filter

the messages reaching the device. It is particularly

interesting for avoiding proximity marketing spam.

3 RESULTS

3.1 Hardware Implementation

Simplicity criteria have been applied in the design of

the sender and receiver beacons. Next figure

summarizes the hardware subsystems of the sender.

Figure 2: Internal beacon design.

A PIC16F88 (Microchip Inc., Arizona.) is the

microcontroller of choice. It responds to a RISC

internal architecture and contains a UART

(Universal Asynchronous Receiver Transmitter)

which is used to connect with the Bluetooth chipset.

We highlight the low power consumption, only 0,8

mA at 4MHz and 3,7V. This voltage is the same for

the Bluetooth chip so we can simplify the power

subsystem.

The EZURIO Bluetooth Chipset (EZURIO Ltd.)

is used because it allows a feasible configuration

with AT commands, supplied through the UART.

Next figure shows the basic connections for this

purpose.

Figure 3: µC – Bluetooth connections through UART pins.

The Memory is a Flash model with a capacity of

512KB divided in 8 sectors and has an access time

of 90ns. Its capacity is enough for storing 2 minute

messages in mp3 audio format. The addressing

mechanism was implemented with three 8-bit

cascaded counters using only 19 outputs (the least

significant outputs).

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183

The flux control was implemented with an

XON/Xoff protocol.

Once the development of the sender was

finalized, we redesigned the receiver with a memory

subsystem based on EEPROM 24LC512 (64KB and

I2C protocol) and adding a LCD Display (Hitachi

44780).

The prototype of the receiver is shown in the

next figure.

Figure 4: The receiver beacon prototype.

To facilitate the wire connection to the Bluetooth

chip, and to test the system, we use the Ezurio

Bluetooth development chip. We can see it on

Figure 6, on the right. The final prototype has only

the Bluetooth chip.

The final result allows the reception of chain

characters in the receiver beacon or files in different

formats (audio or image) in a PDA or in a mobile

phone as shown in the next figure:

Figure 5: Receiving text and files in the LCD and in the

PDA, respectively.

3.2 Software Implementation

The sender beacon has to run two main tasks in its

PIC microcontroller. Firstly, the PIC must configure

a serial communication through its UART. Once the

UART is fully operative, the PIC must configure the

Bluetooth module by sending AT commands.

In this prototype, the memory was previously

loaded using a PC and a Xon/Xoff protocol, as

mentioned above. Further developments will allow

to load the memory through GSM/GPRS messages.

The files stored are sent to the portable device or

the receiver beacon following a simple protocol

described below:

 The receiver beacon waits for an external

enquiry.

 A Bluetooth connection is established.

 The PIC reads the files from memory and sends

them to the receiver beacon.

 When it finishes the connection is released.

The receiver beacon software behaviour is very

similar and it is described below:

 The UART and the Bluetooth module are

configured in a similar way as in the sender

beacon. The receiver beacon is always

discoverable. Moreover, the LCD must be

configured for files in text data format.

 When the connection between beacons is

established, the receiver beacon downloads

the file.

 If it is a text file, it is displayed in the LCD.

However, if the file data format is for audio or

image, the receiver beacon tries to send it to

its corresponding PDA or mobile phone.

As can be observed, this second beacon can

easily filter spam messages from other devices, in

particular, those used in proximity marketing.

All the code was developed with a minimum

number of instructions to be stored in the 64KB

memory of the PIC.

4 CONCLUSIONS

We have shown the feasibility of a low-cost wireless

system for assisting people with disabilities such as

blind, deaf or elderly people. A more acute design

would allow mass production.

The low cost of the receiver/sender is

summarized in the next table:

Table 1: Material Costs.

EZURIO BISMII 22€

Flash Memory/EEPROM Memory 3,45€

8-bit Counters 3,00€

µC PIC16F88 3,13€

LM7805 (Voltage Regulator) 0,60€

Resistors, capacitors, etc 2,50

LCD Display 6€

≈40€

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Further work is in course in order to upload

contents to the sender beacon through GPRS. This

would allow the contents to be broadcast through a

central web-based server.

REFERENCES

Busby, G. Whitehouse, D. 1997. Technology and society:

how information and communication technologies can

enhance the lives of persons with a disability.

Technology and Society, 1997. 'Technology and

society at a Time of Sweeping Change'. Proceedings.,

1997 International Symposium on

Busby, G. 1997. Technology for the disabled and why it

matters to you. Computers in the Service of Mankind:

Helping the Disabled (Digest No: 1997/117), IEE

Colloquium on

Blanchard, S.M. Rohrbach, R.P. 2000. Capstone

engineering design projects to aid disabled persons.

Engineering in Medicine and Biology Society,.

Proceedings of the 22nd Annual International

Conference of the IEEE

Karim, N.A. Nwagboso, C. 2004. Assistive technologies

in public transport: meeting the needs of elderly and

disabled passengers. Information and Communication

Technologies: From Theory to Applications,

Proceedings. 2004 International Conference on

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