Child Monitoring

BlueNanny

Child Monitoring System

Volume III

By

Dimitri Andronikos

School of Information Technology and Electrical Engineering. The University of Queensland.

Submitted for the degree of

Bachelor of Engineering (Honours) in the division of

Computer Systems Engineering, October, 2002.

Letter to the Head Dimitri Peter Andronikos

i.

3 Maralinga Place Carina Heights QLD, 4152 Tel. (07) 3398 8742 Email. [email protected] October 18, 2002

To the Head School of Information Technology and Electrical Engineering The University of Queensland St Lucia, QLD 4072 Dear Professor Kaplan, In accordance with the requirements of the degree of Bachelor of Engineering (Honours) in the division of Computer Systems Engineering, I present the following thesis entitled �BlueNanny � Child Monitoring System�. This work was performed in partnership with Mr Alan Hardcastle and Ms Zon Shih under the supervision of Dr Adam Postula. I declare that the work submitted in this thesis is my own, except as acknowledged in the text and footnotes, and has not been previously submitted for a degree at the University of Queensland or any other institution. Yours sincerely, Dimitri Andronikos

Abstract Dimitri Peter Andronikos

ii.

Abstract Due the frantic lifestyles of parents today, constant supervision of their child can

sometimes be demanding. Parents are constantly concerned about the condition of their

child. They regularly strive to maintain constant child supervision to prevent them from

serious injuries. Even though correct safety measures are being taken to prevent serious

child injury, one sudden lapse of concentration, even for a second, can lead to fatal

injuries. A large number of reported accidents1 with stoves, hot water, swimming pools,

etc., have testified that parents need help.

BlueNanny is the wireless solution to assist all parent or guardians with childminding

and child injury prevention. It aims to accomplish this by generating constant

awareness of the child�s location to the parent. This will hopefully aid to improve

awareness of their child and consequently reduce child injuries. BlueNanny is

engineered to always keep an eye on the children by combining Bluetooth and

proprietary radio frequency (RF) communication.

The design and implementation of BlueNanny hardware and RF communication forms

the topic of this thesis. BlueNanny consists of portable modules to be worn by parent

and child. Hardware for these modules will entail voice signal conversion and user

interfaces constructed for compatibility with Bluetooth communication. The design of

RF beacons employs the use of a grid-based environment in the home. Their hardware

and software for operation is all discussed in this thesis with comprehensive

implementation descriptions reported.

Acknowledgements Dimitri Peter Andronikos

iii.

Acknowledgments This thesis could not have been accomplished without the help and support of many. The BlueNanny Team, Alan Hardcastle and Zon Shih, for the constant persistence as a team through so many all-nighters. Dr. Adam Postula, for motivating us to continue to the final production stages whilst keeping us occupied with related design competitions. Mr. Simon Leung, for maintaining the iLab facilities, and performing all administration work required. My family, for providing me with the necessities in life and encouraging me to reach my full potential. My friends, for allowing me to take my mind of uni studies. iLab guys, for creating a fun working environment even if little work is accomplished.

Table of Contents Dimitri Peter Andronikos

iv.

Contents ABSTRACT................................................................................................................................................ 3 ACKNOWLEDGMENTS ......................................................................................................................... 4 CONTENTS ............................................................................................................................................... 5 TABLE OF FIGURES............................................................................................................................... 7 LIST OF TABLES..................................................................................................................................... 8 CHAPTER 1............................................................................................................................................... 8

INTRODUCTION ........................................................................................................................................ 9 1.1 THESIS MOTIVATION & OBJECTIVES ....................................................................................... 10 1.2 THESIS STRUCTURE ................................................................................................................... 2

CHAPTER 2............................................................................................................................................... 1 BACKGROUND RESEARCH........................................................................................................................ 1

CHAPTER 3............................................................................................................................................... 3 THE BLUENANNY SYSTEM ...................................................................................................................... 3 3.1 PERFORMANCE REQUIREMENTS .............................................................................................. 6 3.2 DESIGN METHODOLOGY ......................................................................................................... 6 3.3 INNOVATIONS AND UNIQUENESS............................................................................................. 7

CHAPTER 4............................................................................................................................................... 8 BLUETOOTH VOICE COMMUNICATION..................................................................................................... 8 4.1 THE BLUENANNY CODEC ....................................................................................................... 8

CHAPTER 5............................................................................................................................................. 12 EYEMODS.............................................................................................................................................. 12 5.1 INSIDE THE EYEMODS........................................................................................................... 13 5.2 RF SPECIFICATIONS AND SELECTION ..................................................................................... 13 5.3 RF TRANSCEIVER AND MICROCONTROLLER INTERFACE....................................................... 14

5.3.1 RF Transceiver Timing Requirements ............................................................................ 14 5.3.2 Oversampling.................................................................................................................. 15 5.3.3 Packet Format................................................................................................................. 16

5.4 RF ANTENNA DESIGN.............................................................................................................. 16 5.5 TRANSMITTING THE EYEMOD IDENTIFICATION .................................................................... 17 5.6 SMARTEYE TEMPERATURE SENSOR...................................................................................... 18

5.6.1 Software Control ............................................................................................................. 20 CHAPTER 6............................................................................................................................................. 23

LCD DISPLAY........................................................................................................................................ 23 6.0.1 LCD Hardware ............................................................................................................... 23 6.0.2 LCD Software.................................................................................................................. 25

6.1 CHILDMOD SECURITY BAND ................................................................................................ 25 6.2 REQUIRED TOOLS ................................................................................................................. 26

CHAPTER 7............................................................................................................................................. 27 SYSTEM EVALUATION............................................................................................................................ 27 7.1 BLUENANNY PHYSICAL EVALUATION................................................................................... 27

Table of Contents Dimitri Peter Andronikos

v.

7.1.1 Size ................................................................................................................................. 27 7.1.2 Weight ............................................................................................................................. 28 7.1.3 Durability........................................................................................................................ 28 7.1.4 Cost ................................................................................................................................. 28 7.1.5 Data Rate......................................................................................................................... 30

7.2 BLUENANNY PERFORMANCE EVALUATION........................................................................... 31 CHAPTER 8............................................................................................................................................. 33

FUTURE DEVELOPMENT......................................................................................................................... 33 CHAPTER 9............................................................................................................................................. 34

CONCLUSION ......................................................................................................................................... 34 REFERENCES ........................................................................................................................................ 35 APPENDIX............................................................................................................................................... 37

List of Tables Dimitri Peter Andronikos

vii.

Table of Figures

Figure 1: Digital Angel System��.1

Figure 2: BlueNanny Block Diagram��5

Figure 3: PCM Jumpers on the ROK module��....9

Figure 4: PCM algorithm sampling��.10

Figure 5: Motorola Codec Pin-out��...11

Figure 6: EyeMod employed in a BlueNanny Environment��...12

Figure 7: Oversampling Algorithm��.15

Figure 8: EyeMod ID 5th byte��.16

Figure 9: Dipole antenna radiation Pattern��..17

Figure 10: DS18B20 Hardware Configuration��...�.19

Figure 11: DS18B20 Reset Pulse Timing��....20

Figure 12: DS18B20 Read and Write function timing��...� 21

Figure 13: SmartEye Mechanical View��..� 22

Figure 14: LCD Pin Configuration��. 24

Figure 15: ChildMod Security Band��.. 26

Figure 16: Bluetooth quality versus distance between units��.. 31

List of Tables Dimitri Peter Andronikos

vii.

List of Tables

Table 1: Probability calculations for EID collision��18

Table 2: LCD Pin-out Summary��.23

Table 3: BlueNanny module size��27

Table 4: BlueNanny module weights��..28

Table 5: BlueNanny Budget��29

Table 6: BlueNanny data rates��30

Chapter 1 Dimitri Peter Andronikos

1.

CHAPTER 1

Introduction

Child safety at home has been identified as one of the most important issues that

concern parents1. The average home is responsible for the highest number of injuries

amongst young children. This statistic is greater than its nearest competitor by over 5

times. An understanding of how this figure is determined must be continually

addressed. Due to the busy lifestyle of today�s parents, continual supervision of their

children can sometime be demanding. For a serious and sometimes even fatal injury to

occur, a sudden lapse of awareness of the child�s whereabouts is all that is required and

can occur within a matter of seconds. The outcome can range from minor to disastrous,

but is and outcome that can be avoided with today�s solutions and technologies.

Our product, BlueNanny, is a home-use system developed to always keep an eye on the

children at home. BlueNanny is a complete wireless system created to assist

childminding and reduce the risk of child injury at home. It uses both Bluetooth

technology and proprietary RF communication to provide parents with an instantaneous

voice communication link to their child with constant awareness of their child�s

location. It will alert the parent when children come close to potential dangers.

BlueNanny is capable of considering parental needs in varying household environments.

There are already some commercially available products which focus on child

monitoring. Digital Angel2 and Kidbug3 are just two examples of these and are looked

at in more detail in chapter 2. They have similar functionality to BlueNanny but do not

allow any flexibility when personalising system alerts and settings. BlueNanny

supports the need for children to learn their boundaries while not strictly confining


2.

them. It is a system that can be incorporated into the lifestyle of parents and will

promote the freedom of mobility in their daily lives. Hence, allows parents to live their

hectic lifestyle whilst always supervising their children.

1.1 Thesis Motivation & Objectives

The BlueNanny system proposed above represents a joint effort with two colleagues,

Alan Hardcastle and Zon Shih, to form the BlueNanny Team. This project was

undertaken to become the final year thesis for the Bachelor of Engineering Degree. The

appropriately named BlueNanny system provides parents or guardians, assistance, in

childminding at home. Due to the complexity of this task, its sections were divided

among team members.

The BlueNanny system was also motivated by worldwide competitions that reward the

design of innovative products. The Computer Society International Design

Competition4 (CSIDC) by the IEEE Computer Society is run to advance excellence in

computer science and computer engineering education by encouraging, teams of

students, to design and implement computer-based solutions to real-world problems.

For entry, a four page proposal of the product was sent by March with selection of

participants for the competition known one month later. On selection, assisting

hardware and software was donated by the competition sponsors. This package

contained Ericsson 101 008 Bluetooth ROK modules5 and Microsoft Windows XP.

Due to this equipment, our product design involved to use of these products. A

comprehensive 30 page report, which was due in May, was required for entry to the

final stages of the competition. Based on progress and results, the report was compiled,

by the BlueNanny Team, which contributed to final design specification of BlueNanny.

The Young Inventors Awards6 (YIA), held by Hewlett-Packard Asia-Pacific and Far

Eastern Economic Review, is the second competition that further motivated BlueNanny.

This competition is also run to encourage innovative ideas in the field of computer

technology. For entry, a five hundred word outline of the product outline is required


3.

and finalists are selected according to uniqueness of ideas. This outline report was

submitted in September and selected finalists will be notified at the end of October.

This thesis discusses and overview of the BlueNanny system which participated in the

above competitions. It will include all the work completed by Dimitri Andronikos with-

respect-to the BlueNanny project. This comprises of the design of the voice codec

circuit, EyeMod hardware, ParentMod Hardware, software design and any other

components of the project aiding the completion of the final product.

1.2 Thesis Structure

This thesis details the design and implementation of a system that addresses the

problems facing parents with attempt that have tried, but failed to deal with these

problems in Section 1.1. The BlueNanny monitoring system is a wireless alternative to

other child monitoring systems. It was designed purely with the user in mind.

Chapter 2 - provides background research of current child minding systems. A

summary of a few commercially available products are described with

their flaws illustrated.

Chapter 3 - explains the BlueNanny system. Is describes the functionality of the

system and the modules it comprises of. It will also outline the

innovative features associated with BlueNanny.

Chapter 4 - presents the description and operation details of the voice codec. It will

explain the purpose for its use and how it operates with Bluetooth.

Chapter 5 - introduces the EyeMods. It will explain their purpose in BlueNanny,

what they comprise of, how and what they communicate.

Chapter 6 - delves into the remaining miscellaneous tasks performed for BlueNanny

completion. These include a driver for the LCD display and construction

of the ChildMod security belt.

Chapter 7 - compares goals set during initial stages of the thesis to the end product.


4.

Chapter 8 - suggests improvements to the current version of the wireless

communication use in the BlueNanny system. Also feature

improvements.

Chapter 9 - concludes by discussing the outcome to the BlueNanny project with any

related findings.


5.

CHAPTER 2

Background Research

In today�s marketplace, other similar competitors of the electronic child monitoring

system are available. Two of the more common systems are the Digital Angel and

Kidbug.

The Digital Angel consists of a bio-watch and beeper styled communication-tracker

device. Digital Angel works well in outdoor scenarios, with Global Positioning System

(GPS) technology used. The watch style tracker provides the location and condition of

the wearer. Figure 1 displays the modules used in the Digital Angel system.

The caretaker will be notified of any emergencies occurring to the wearer by the Digital

Angel Operating Centre. These notifications can be transferred to either the caretaker�s

mobile phone or their Personal Digital Assistant

(PDA). Although this device provides an

accurate whereabouts of the wearer, it targets

more to adults and seniors in society who

require mental and physical health care. It will

give the caretaker access to the wearer�s real-

time condition. If it was to be worn by a child,

it would not educate the child of potential

dangers in the environment. Hence, doesn�t

assist in preventing accidents, more to assist

after an accident has occurred. It also does not

allow the parent to contact their child and interact via voice, therefore not giving the

child a sense of security and comfort.

Figure 1: Digital Angel System2


6.

The Kidbug was derived from the success of CarBug. Kidbug is a plan to allow

tracking of a child�s location through a bug on the child�s clothes. It uses mobile cell

technology to gain access to the GPS network to find the satellite location of your child.

A subscription to the network and a mobile phone is all that is needed for the caretaker

to have an immediate and accurate location of your child. Although, KidBug also fails

to prevents children from accidents. It will not allow any interaction with between

parent and child. This system is only required when a child is lost therefore no

education of the child�s misbehaviour is recognised.

BlueNanny succeeds where other systems fail. It will educate children of potential

dangers, allow parent to setup their personal configurations and provide complete

awareness of their child.


7.

CHAPTER 3

The BlueNanny System

BlueNanny is a wireless Bluetooth-based solution to assist in childminding. It is a

system designed for the supervisory user such as a parent or guardian, to supervise

children in a domestic environment when they are out of sight. After outlining the main

reason for injuries with young children, BlueNanny aims to help prevents such injuries.

It operates by providing parents immediate alerts when their child is in a dangerous

area. BlueNanny will detect the location of children and provides the parent this

information for their utilization. The parent has the option to respond to the alerts

and/or contact their child through the wireless two-way voice communication that

BlueNanny provides. BlueNanny will succeed to provide constant child awareness to

allow peace of mind for any parent.

The BlueNanny system provides parents with information regarding the locations of

children by visual and audible alerts. It uses both Bluetooth technology and proprietary

Radio Frequency (RF) communication as a means of wireless communication between

modules. Alerts can occur if any of the children in the system moves within proximity

of an unsafe or restricted area that is predetermined by the user.

System operation begins with the user placing units with embedded RF beacons, called

EyeMods, in selected child minding regions within the home. There are three different

classes of EyeMods that BlueNanny provides: the Local Eye, Point Eye and Smart Eye.

The Local Eye gives identification to a region of 3 metres (suitable for placement in

rooms), while the Point Eye identifies a region of 1 meter (suitable for placement neat

dangerous objects or areas such as the pool gate). The Smart Eye identifies the

potential dangers in its immediate surrounding (suitable for stoves, fireplace, etc).


8.

The BlueNanny innovative features are:

● Detect children (and notify parent) if a child enters an area where

potential dangers are already identified.

● Notify parent if a child leaves a predetermined area.

● Detect extreme temperatures in surroundings and notify parent if

determined that potential danger exists.

● Educate children about potentially dangerous household areas.

● Provide a two-way phone quality voice communication.

● Offer adjustable levels of childminding possible demanded by changing

parental focus (i.e. age of a child, changing environment).

● Support the need for children to learn their boundaries while not strictly

confining them.

BlueNanny is configured using the BlueNanny Application Software (BlueNApp). The

system configuration data is transmitted wirelessly via Bluetooth to a parental unit,

called ParentMod. The children carry units called ChildMods which dynamically

configures from the ParentMod. The EyeMod uses a 433.93 MHz RF signal to

communicate to the ChildMod when a child enters an EyeMod region. Bluetooth

technology is used between ParentMod and ChildMod to establish simultaneous data

and voice communication. Bluetooth allows for a secure and wireless connection.

Figure 2, on the next page, illustrates the overall BlueNanny system and the make-up of

each module.


9.

Figure 2: BlueNanny Block Diagram


10.

3.1 Performance Requirements

There are several performance requirements that BlueNanny aims to fulfil. BlueNanny

must first meet the functional requirements whilst maintaining user � friendliness in

operation. A child�s safety depends largely on a fast system response time, which can

be achieved by real-time data and voice processing. A secure connection between the

ParentMod and ChildMod is vital in preventing intruders from eavesdropping. The

BlueNApp system software must provide security in order to avoid other user tampering

with the systems configurations. This is achieved by and authorisation log-on screen

which will database personal settings for each user. The ParentMod, ChildMod and

EyeMods are all batteries powered. Therefore, low power consumption is required, to

ensure long battery life. As the ParentMod and ChildMod are designed to be portable

and wearable units, they need to be robust, compact and lightweight.

3.2 Design Methodology

The project consists of the following modules: BlueNApp software, ParentMod

Hardware, ChildMod Hardware, Bluetooth communication and RF communication

modules. Working in parallel helps to meet project deadlines. Project modules were

all tested either on breadboard or printed circuit board (PCB) before any final

integration and testing. The module designs were specified in respect to product

accessibility and developed from the user�s perspective to optimise the product

application, capability, price and performance. These include choosing a standardised

system voltage level at +3V DC to comply with Bluetooth, which helps to attain low

power consumption levels for the system. One major constraint encountered which

altered the design of the system was the current indoor navigation technologies. The

Bluetooth module will not give accurate separation distance between another Bluetooth

module. To overcome this difficulty, EyeMods were designed to act as beacons in a

grid arrangement. If the grid was pre-defined, any point within the grid will therefore

have a location with-respect-to the grid arrangement.


11.

The design of the BlueNanny product was divided into sections and assigned to group

members with in the BlueNanny team. Reference to other sections of the BlueNanny

system can be seen below:

● Zon Shih - Volume 17: BlueNApp Software

● Alan Hardcastle - Volume 28: ParentMod Hardware

ChildMod Hardware

EyeMod Hardware

Bluetooth Communication

RF Communication

● Dimitri Andronikos - Volume 3: ParentMod Hardware

ChildMod Hardware

EyeMod Hardware

RF Communication

LCD Driver

3.3 Innovations and Uniqueness

The project innovation is to use today�s advance technologies to aid parents in

childminding. BlueNanny allows parents to always keep an eye on more than one child

at different places at once. Built on the concept of child awareness, BlueNanny has the

ability to offer various degrees of childminding levels that could be demanded by

children of different ages. BlueNanny focuses on preventing accidents by monitoring

and educating children about dangers in the home. This reduces child injury risks and

relieves stress for parents. Today, no commercial product offers the same set of

features as BlueNanny. The uniqueness of BlueNanny lies in its ability to integrate

technologies such as Bluetooth and RF communications in child safety prevention

schemes. Additionally, BlueNanny has other unique features such as knowing when a

child has left the detectable range or removes their ChildMod. Configuration of the

system is user-friendly with a well designed interface and wireless data exchange

between the modules. The user does not need to manipulate hardware during the setup.


12.

CHAPTER 4

Bluetooth Voice Communication

For Bluetooth voice communication, the use of a voice codec is required. A codec

(codec-decoder) is used to convert an analog signal into a digital stream. This becomes

useful when performing a wireless transmission of an analog signal. As voice is an

analog signal a device know as a voice codec can be used to convert this signal into a

digital stream to allow digital transmission. Once voice is digitised, it may be

transmitted long distances without degradation. A codec is a single device that does

both the Analog-to-Digital and Digital-to-Analog conversions.

4.1 The BlueNanny Codec

Voice communication between the ParentMod and ChildMod allows immediate

interaction between the parent and child. This provides the parent, a direct connection

to the child in order to maintain constant awareness and to give any reassurance desired.

Our BlueNanny product will consist of the Ericsson 101 007 Bluetooth ROK module

which provides the Bluetooth connection between parent and child modules. Since the

Ericsson Bluetooth modules supports synchronous voice data transmission (SCO link) a

pulse code modulation (PCM) codec chip was used to transmit voice signals between

the parent and child modules. There are �Jumpers� located on the Bluetooth Module to

get convenient access to the SCO link. Figure 3 highlights the location of these

jumpers on the ROK Module and displays a pin description.


13.

This Bluetooth module performs voice data compression, which results in a smaller

bandwidth utilisation and better sound quality. Selection of the Codec chip was

decided upon many factors such as operation voltage and bit resolution. The Motorola

MC145483 13-bit linear Pulse Code Modulation (PCM) Codec9 is used in the design of

our system since it meets most requirement for compatibility with the Bluetooth

module. The codec can operate from the +3.3V powers supply produced by the PCM

�Jumpers� (pin 6). It accepts a linear, 2s complement digital input data using Mu-Law

compression which will be all produced by the Bluetooth Module. As well as, the bit

rate synchronization clock, also sourced by the Bluetooth Module

The PCM algorithm is one of many approaches used to digitize a voice signal. The

basic feature of Motorola�s MC145483 PCM algorithm is that a voice frame is sampled

13 times by a clock that is provided by the Bluetooth Module. Each voice frame is

synchronised by the Bluetooth Module�s PCM_SYNC pin which outputs an 8kHz

clock. Therefore this means that the analog input signal is sampled at a rate of 8000

times per second with a 13-bit sample bandwidth. Each sample is then sign-extended

to 16-bit long as required by the receiving Bluetooth device. The frame is sampled at a

fixed time interval between 32 to 512 times the 8kHz frame synchronizing clock (256 �

Figure 3: PCM jumpers on the ROK Module


14.

4096kHz) and is internally stepped down to 256kHz by the codec for all Analog-to-

Digital operations. Figure 4 shows the PCM algorithm sampling a voice frame at a

fixed time interval.

Each sample bit is clocked from the Bluetooth�s PCM_CLK pin which provides a

2.048MHz clock signal needed to drive PCM bits stream out on the data transmit (DT)

pin of the codec. This audio bit stream is routed to the PCM_IN input of the Bluetooth

device and is then transmitted to other Bluetooth module through an established SCO

connection. Figure 5 illustrates this pin connection to the Motorola codec.

Upon receiving the PCM audio data, the receiving Bluetooth module must first convert

the digital voice stream back to an analog signal before producing voice through a

speaker. The Motorola MC145483 codec also supports this decoding method. The

PCM data, received from the PCM_OUT interface of the Bluetooth Module is

transferred to the Motorola codec through its DR input pin. This transfer operation

timing is kept consistent with the synchronisation of the frames and clocking of the data

bits which are controlled by the PCM_SYNC and PCM_CLK of the Bluetooth Module,

respectively.

The codec also requires a master clock signal for correct operation. This signal will be

applied to the Master Clock pin (MCLK) of the codec. This pin will automatically

Figure 4: PCM alogorithm sampling10


15.

accept a 256, 512, 1536, 1544, 2048, 2560, or 4096kHz clock pulse and will internally

step down this pulse to a 256kHz clock. This clock will provide sequencing signals for

internal filters and amplifiers. In the BlueNanny prototype the JITO-2 oscillator11 is

used to supply a 1.544Mhz clock signal. This external clock oscillator is necessary to

overcome the inability of the PCM_CLK to provide a continuous clock signal for the

codec. It will be used to generate sequencing signals needed by the internal filters.

Using an external clock oscillator will allow the codec�s internal timing to be clocked to

keep it operating properly.

Finally, discrete external circuitry is required for operation of internal operational

amplifiers. This circuitry can adjust the amplification gain of the input and output

analog signals. Figure 5 shows the pin-out information of the 13-bit Linear PCM

codec. The final schematic can be viewed in the Appendix.

Figure 5: Motorola Codec Pin-out


16.

CHAPTER 5

EyeMods

EyeMods are battery operated radio frequency (RF) beacons which are used to transmit

their Eyemod ID (EID) to any receiving ChildMods in proximity. The Eyemods will be

place through-out the home to regions which the parent desires supervision. Each EID

will therefore be designated to the region where the EyeMod is located which will

interpret the location, of the ChildMod, with respect to the home. The three classes of

EyeMod are: Local Eyes, Point Eyes and Smart Eyes. The signal range of a Local Eye

is approximately a 3m radius. These are typically used for general location information

of child and placed in an open area. The Point Eyes have a signal range of

approximately 1m radius. They are typically placed near dangerous objects or in small

confined areas in the home, for example pool gate or expensive vase. A Smart Eye

additionally contains a temperature sensor and would characteristically be used in

temperature influenced environments such as the fireplace, stove, etc. Figure 6

illustrates EyeMod positioning around the home.

Local Eye Point Eye Smart Eye Parent Child Bluetooth Connection

Figure 6: Eyemods employed in a BlueNanny Environment


17

5.1 Inside the EyeMods

Each EyeMod contains a microcontroller and RF circuitry with the SmartEye having

also a temperature sensor. More in depth information on what the SmartEye comprises

of is explained in section 5.7. The selected microcontroller for the BlueNanny Eyemods

is the PIC16F627 from Microchip12. The PIC16F627 is a memory efficient

microcontroller (1k Program Memory) and inexpensive solution. It has a low power

consumption (15uA) whilst being compatible to operate from a +3V battery supply.

The nRF401 433.92MHz RF transceiver from Nordic13 provides the wireless

communications between EyeMod and ChildMod. The microcontroller�s Universal

Synchronous Asynchronous Receiver Transmitter (USART) interface will be used for

communication with the nRF401 transceiver. The PIC16F627 onboard comparator is

used to indicate a low voltage level warning for all EyeMods. By internally setting a

reference voltage at +2.5V, the +3V battery supply will be continually checked against

this reference voltage and will alert users by flashing a LED if the voltage was to fall

below. All EyeMods are powered from 2×1.5V AA batteries.

5.2 RF specifications and selection

The Nordic nRF401 is a true single chip UHF transceiver designed to operate in the

433.93MHz ISM (Industrial, Scientific and Medical) frequency band. It features

Frequency Shift Keying (FSK) modulation and demodulation capability. The nRF401

operates at bit rates up to 20kbit/s. Selection of the transceiver was made after careful

evaluation of many transceivers. The nRF401 was decided upon as it was compatible

with the battery supply voltage level of +3V and was supplied with comprehensive

support to make them operational. The Nordic website13 supplied us with relevant PCB

schematics which require very few external components. Initialising the nRF401 will

require the transceiver to be placed in transmitting mode. This is accomplished by

enabling the transmitter enable pin (TXEN = pin 19). The transmission channel must

also be set. Channel 1 will be used for the EyeMods which transmits at frequency of

433.93MHz.


18.

5.3 RF Transceiver and Microcontroller Interface

The nRF401 transceivers are controlled by the PIC16F627 through its USART

capabilities. As they will only be required to transmit the EID, setting up the receiver

side will not be needed. USART works by transmitting bytes through the TX pin (pin

8) asynchronously from the PIC16F627. This is accomplished after bits have been

shifted serially into the USART buffer. On detection of a full buffer, the buffer data

will be serially clocked through the TX pin. The Transmit Shift Register Status bit

(TRMT) will play the role of a busy flag by going high on detection of an empty buffer.

Using this bit as a buffer status bit will avoid corruption of bytes. Before the data is

transmitted through the nRF410 transceiver, the data is passed through a Schmitt trigger

due to USART supplying an inverted output.

When determining the required baud rate for transmission, the necessity of a fast baud

rate needs to be questioned. A delay of half a second may seem fast in real life but

actually is very slow when transmitting through RF. Therefore a transmission time of

less than one second is more than sufficient for its purpose in this project. Therefore,

according to the PIC16F627 datasheet14, a baud rate of 2.4kbit/s with a 5.0688 MHz

crystal results in a zero error rate. This was the selected configuration for the

BlueNanny EyeMods.

5.3.1 RF Transceiver Timing Requirements

The nRF401 must require correct timing for

operation. To avoid spurious emission outside

the ISM-band when the power is switched on,

the TXEN-input must be kept low until the

synthesised frequency is stable, as shown in

figure 7.

Figure 7: Oversampling Algorithm


19.

5.3.2 Oversampling

In order to assure a reliable link, the nRF401 requires oversampling. Oversampling

with a rate of 3 times the bit-rate with weighting of the samples, will be noise resistant.

However, timing of each sample must be consistent or successful oversampling will not

be evident. Conveniently, the microcontroller being used is designed to be compatible

with RF transceivers. The PIC16F627 USART capabilities conducts the sampling of

each bit, three times, at arrival. Refer to the Microcontroller selection part of this thesis

in section 5.2 for an in depth description of their function in the EyeMods. Figure 7

shows the oversampling Algorithm used by the PIC16F627.

Figure 7: Oversampling Algorithm


20.

5.3.3 Packet Format

When setting up the packet format for the EID, the packet is 5 bytes long and must

begin with a preamble. The suggested preamble by the nRF401 datasheet13 is 2 bytes

consisting of: 01010101 (�55�), to cycle the receiver. The third and four byte in the

packet will be used to indicate the start of the packet. The fifth and final byte of the

packet will contain information about the EyeMod. Figure 8 illustrates the bit details in

the fifth byte

As shown in figure 8 the EyeMod ID will be assigned one of 16 values. Enhancements

can be made by adding an extra byte for the EyeMod ID if more than 16 EyeMods are

used. The Parity Bit will provide error checking to detect any bit errors occur after

transmission.

5.4 RF Antenna Design

The Eyemods in the BlueNanny system all use omni-directional antenna design. Due to

the large range obtained from properly tuned antennas, a single wire design proved

sufficient with-respect-to range. Therefore a 5cm long dipole antenna transmitted

successfully at a range of 3m, adequate for use on the LocalEyes. The PointEye and

SmartEye only require a transmission range of 1m to which a 1cm long dipole antenna

is adequate. The antenna pattern will diverse in all directions. Shielding of the antenna

Figure 8: EyeMod ID 5th byte


21.

can allow transmission in one direction. Generally, the omni-directional radiation

pattern is recommended. Figure 9 shows the vertical radiation pattern of an EyeMod

dipole antenna transmitting in all directions.

5.5 Transmitting the EyeMod Identification

Even though the nRF401 has a maximum data rate of 20kbits/s, a 2.4kbit/s data

rate of was selected and mentioned in section 5.4. Each EyeMod ID packet is 5-bytes

(40-bits) in length with a packet the format explained in section 5.4.2. At 2.4kbits/s, it

takes approximately 420µs to transmit one bit. It therefore takes 17ms to transmit an

EID. In order to prevent the RF signals that are transmitting from different Eyes from

colliding with each other, each packet is transmitted at times set by a random number

generator create from software. This is based on transmitting at intervals of one second,

which is generated each time by the PIC16F627 using a random offset. This gives 60

available transmission slots that a 17ms EID can be sent. A probability algorithm

shown in Table 1 is used to determine the possibility of two EID packets colliding.

Figure 9: Dipole antenna radiation Pattern


22.

Therefore there is less than 0.06% chance of two EID packets colliding per transmission

interval. If it does occur, there is little possibility of a collision during the next second

since a random number is used for each EID transmission.

Between transmitting each EID packet the nRF401 can switch to standby mode. To

send an EID, 4ms are required for the nRF401 to power up from standby mode and

transmit the 17ms packet. Only one EID is sent per second, therefore the nRF401 is in

standby mode for approximately 99% of the time, lowering the power consumption of

an EyeMod.

The RF signal between an EyeMod and ChildMod has no line-of-sight restrictions.

This eliminates restrictions when a user may wish to position an EyeMod. However, a

problem may arise if an EyeMod is placed next to a wall and the wall allows the RF

signal to be received on its other side. This problem is realized and a possible solution

is using adjustable RF shielding on the Eye, as mention in section 5.5, which limits the

direction of the RF signal.

5.6 SmartEye Temperature Sensor

Burns and scalds, are one of the top five nature of injury that most occurs to children16.

The design of a SmartEye incorporates the use of a temperature sensor to rectify this

statistic. The SmartEye is designed to be used in temperature influenced environments

such as the fireplace, stove, etc. The SmartEye will contain similar hardware to that of

the LocalEye and PointEye, but will also comprise of a DS18B20 1-Wire® Temperature

Data Results

EID transmission time: 17ms Probability of EID being sent in one of 60 transmission slots: 1/60 = 0.017

Probability that another EID could be sent that will overlap the first: 2/60 = 0.033 Probability of two EID packets colliding: 0.017 x 0.033 = 5.7x10e-4

Table 1: Probability calculations for EID collision


23.

Sensor by Dallas17. This will allow the SmartEye to react dynamically with the

surrounding environment.

The DS18B20 Digital Thermometer18 provides 9 to 12�bit centigrade temperature

measurements and has an alarm function with nonvolatile user-programmable upper and

lower trigger points. The DS18B20 communicates over a 1-Wire® bus that connects

directly to a bi-directional port pin on the PIC16F627 microcontroller. It has an

operating temperature range of �55°C to +125°C and is accurate to +/-0.5ºC over the

range of �10°C to +85°C. For the BlueNanny SmartEye application, very little external

circuitry is needed to interface with the DS18B20. Figure 10 illustrates the simplicity of

the hardware configuration when using 1-Wire® temperature sensors. The SmartEye

will use pin 0 on PORT B of the PIC16F627 to provide communication access and

power to the DS18B20. Power to the bus is provided through the 4.7kOhm pullup

resistor from a 3V supply rail supplied by the 2×1.5V AA battery source.

With all 1-Wire® interface requirements, accurate timing functions need to be

established. A delay function is correctly tuned with the 5.06868Mhz crystal. This

delay function allows high and low pulses to occur within a constant timeslot. Firstly,

an initialisation pulse will occur to detect the available 1-Wire® device. Temperature

conversion is then conducted. The microcontroller must wait for a certain time interval

until the conversion is completed (usually approx. 750ms) before the 12-bit temperature

value is stored in the scratch pad or volatile memory. This can be read and converted

into a decimal value and multiplied by the degree resolution to give the temperature in

degrees Celsius.

Figure 10: DS18B20 Hardware Configuration19


24.

With respects to BlueNanny, we have set the temperature threshold value as 47°C for

this as the minimum unsafe temperature for young children according to statistics16.

Therefore on detection of surrounding temperature above our set threshold, the RF

transceivers begin transmitting its EID to alert any nearby ChildMods of this hazardous

location.

5.6.1 Software Control

Timing and delays play an integral part when applying software to control hardware

devices. To accurately control the special timing requirements of the 1-Wire interface,

certain key functions must be established in order to maintain regular timeslots.

Firstly, to initiate the DS18B20 sensor, a reset pulse must be valid on the data line.

This is accomplished by low signal from the microcontroller. After holding the data

line low for the required timeslot, the data line is release by the microcontroller which

then the pullup resistor reverts the data line to high. The DS18B20 responds by

indicating its presence by pulling the data line low. Figure 11 Illustrate an example of

the reset and present pulse sequence.

After successful initialisation of the DS18B20, the sensor must execute a ROM

command before performing any functions. Command flowcharts have been included

Figure 11: DS18B20 Reset Pulse Timing20


25.

in the Appendix. In order to write commands, a write function is created to perform

correct timing and sequencing. Figure 12 illustrate timing intervals.

During the Write 0 time slot, the PIC16F627 pulls the line low for the duration of the

time slot. However, during the Write 1 time slot, the PIC16F627 pulls the line low and

then releases the line within 15 us after the start of the time slot. A read time slot is

initiated when the PIC16F627 pulls the bus low for 1us, and then releases it so the

DS18B20 can take control of the line and present valid data (high or low). All read

time slots must be 60us to 120us in duration with a minimum 1us recovery time

between cycles.

With functional read and write functions, hexadecimal commands are written to the

DS18B20 to perform our required tasks. The SmartEye requires two commands from

the DS18B20 which are convert temperature (0x44h) and read scratch pad (0xBEh).

Convert temperature converts the surrounding temperature into a 16-bit number. This

command requires approximately 750ms to complete therefore the busy status flag is

continually checked for completion before continuing. On completion, the 16-bit value

is store into the scratch-pad. The scratch pad is then read with the temperature

Figure 12: DS18B20 Read and Write function timing20


26.

compared against the 16-bit value for 47°C to determine whether to transmit. Figure 13

display the mechanical view of the SmartEye module.

Figure 13: SmartEye Mechanical View

L Chapter 6 Dimitri Peter Andronikos

27.

CHAPTER 6

LCD Display

To provide the parent user with an easy display interface for the ParentMod, we have

included a Liquid Crystal Display (LCD). This display will inform the parent of any

alerts from the ChildMod, the location on request of their child and the current status of

the ParentMod. The ParentMod has been installed with a Hitachi HD44780-based LCD

module with the follow specifications displayed in the Appendix. In order for the LCD

display to communicate with the ParentMod�s PIC16F876 microcontroller, a LCD

driver, to operate the LCD module, is written in C.

6.0.1 LCD Hardware

The LCD display module is built with a controller that has two 8-bit registers, an

instruction register (IR) and a data register (DR). It provides 16 pins for interfacing

with microcontrollers. Table 2 summarises the 16 pins provided by standard Hitachi

LCD module.

Pin Number Symbol Function

1 Vss Ground

2 Vcc Power Supply (+3V)

3 Vo Contrast Adjust

4 RS Register Select

5 R/W Read/Write

6 E Chip Enable Select

7-14 DB0-DB7 Data Bit 0 – Data Bit 7

15 A LED Backlight +

16 K LED Backlight –

Table 2: LCD Pin-out Summary


28.

By the register selector (RS) signal, the two registers can be selected. The IR stores

instruction codes, such as display clear and cursor shift, and address information for

display data RAM (DDRAM) and character generator (CGRAM). The IR can only be

written from the microcontroller. The DR temporarily stores data to be written to the

DDRAM or CGRAM. When the address information is written into the IR, then data is

stored into the DR from DDRAM or CGRAM.

Due to minimal port pins remaining on the PIC16F876 microcontroller, we initially

opted to use the PIC16F877 which comprises of 2 extra ports (D � 8pins and E � 6pins)

for use with the LCD module. Later, after realizing pin saving techniques, the LCD

driver was written for the PIC16F876 microcontroller. The pin configuration is shown

in figure 14.

The pin saving technique came about from a function which is supported by the LCD

module. It allows the microcontroller to sent commands through the data pins at four

bits at a time hence reducing four pins. Also, a one pin is saved by routing the R/W pin

to ground. This can be perform due to the purpose for the LCD, on the ParentMod, is

for only writing to (R/W = 0), not reading from (R/W = 1). Therefore a total of seven

port pins were required to successfully interface the LCD to the PIC16F876

microcontroller.

Figure 14: LCD Pin Configuration


29.

6.0.2 LCD Software

The LCD driver is written in C and compiled using the Hitech C compiler. Refer to

section 6.3 for a more in depth look at the tools used throughout this project. Firstly, the

LED module accepts instruction by strobing (low-high-low) the enable (E) pin of the

LCD module. Therefore for initialisation, the desired LCD modes need to be selected

to determine the display and input format. This is performed by selecting the data

register (RS = 0) and writing the required hexadecimal commands. For the ParentMod

the LCD is put into 4 bit mode, with a 2 line display and an incremental cursor. The

input format may be change later to allow any animation on the LCD display. After

correct initialisation of the LCD module, writing the correct ASCII value will result in

the character being displayed onto the LCD. The LCD module contains a look-up table

to output the correct character display. The LCD module look-up table can be seen in

the Appendix. One final function command is coded to allow the user of the driver easy

useability. This is accomplished by allowing the user to only input a string in the

driver function for display to the LCD.

6.1 ChildMod Security Band

In order for the BlueNanny system to work, the child must wear the ChildMod at all

times. Its purpose is defeated it the child removes their module. That is why the

security band is implemented to firstly, hold the ChildMod tightly to the child�s waist,

and also, to detect and alert the parent if the ChildMod is removed. This band is lined

with a thin wire which uses a pull-up resistor on one end that connects to a port pin of

the ChildMod�s PIC16F876 microcontroller. The wire is connected to ground and

creates a closed loop with the port pin when the band is connected. If this loop is

broken, a pin on the PIC16F876 detects the input signal and sends an emergency alert

message to the ParentMod which notifies the parent with the highest alert. Figure 15

illustrates the ChildMod security band.


30.

6.2 Required tools

To program the PIC16F627 and PIC16F876 microcontrollers, the selection of compiler

and transfer software is important for correct functionality of the program on the chip.

With C the preferred programming language, Hitech C, a quite old but reliable compiler

was used for building source code. It will compile, assemble and link entire programs

into a hexadecimal (HEX) format file, which is ready for onboard application. The

process of transferring this file into the processor requires a PIC programming board

which accepts the HEX file through the communication port of a computer. Software

required for transferring operations is PICALL21 which specializes on only PIC

processor transfers. Once programmed, a simple breadboard circuit with the processor

is adequate for testing and debugging purposes.

Figure 15: ChildMod Security Band


31.

CHAPTER 7

System Evaluation

This section will evaluate the final BlueNanny system. It will compare goals set during

initial stages of the thesis to the end product. The built prototype of BlueNanny

implemented all the innovative features first proposed.

7.1 BlueNanny physical Evaluation

7.1.1 Size

A summary of the BlueNanny modules is shown in Table 3.

Module Length Width Height

ParentMod 140 mm 80 mm 38 mm

ChildMod 140 mm 80 mm 34 mm

EyeMod 90 mm 65 mm 26 mm

Although ParentMod and ChildMod are fairly largely sized, our design remains only as

a working prototype of the system. Smaller modules would be ideal for real-life

production.

Table 3: BlueNanny module size


32.

7.1.2 Weight

The weight of the BlueNanny modules is summarized in Table 4.

Module Weight

ParentMod 192 grams

ChildMod 154 grams

EyeMod 65 grams

The overall weights of the modules were reasonable although the ChildMod would

preferably be much lighter. Due to large sized and heavier components in the prototype

construction, a lighter ChildMod can be achieved for real-life production.

7.1.3 Durability

The BlueNanny system proved durable to withstand the battering normal day tasks.

Also the ChildMod security belt proved valuable against child tampering.

7.1.4 Cost

Table 5 provides the total budget of the BlueNanny system.

Table 4: BlueNanny module weights


33.

Unit

Item

Q T Y

Cost (AU$)

+1

Cost (AU$)

× QTY BlueNApp Ericsson Bluetooth 101 007 ROK Modules1 1 10.00 10.00 ParentMod Ericsson Bluetooth 101 007 ROK Modules1 1 10.00 10.00

PIC16F876 Microcontroller 1 22.08 22.08 Motorola MC145483 13-bit Linear PCM Codec 1 11.46 11.46 Trident Microsystems LCD 1 81.16 81.16 Micro Speaker 1 2.72 2.72 Electret Condenser Microphone 1 2.50 2.50 Buttons 5 1.90 10.00 RS232 1 6.00 6.00 HCF407BT Quad Input OR Gate 1 1.45 1.45 LM393 Comparator 1 3.00 3.00 Casing and Support 1 32.80 32.80 Electronic Components & PCB 1 30.00 30.00

ChildMod Ericsson Bluetooth 101 007 ROK Modules1 1 10.00 10.00 PIC16F876 Microcontroller 2 22.08 44.16 Motorola MC145483 13-bit Linear PCM Codec 1 4.39 4.39 Micro Speaker 1 2.72 2.72 Electret Condenser Microphone 1 2.50 2.50 Button 1 1.00 1.00 Nordic nRF401 Transceiver 1 11.54 11.54 RS232 1 6.00 6.00 HCF407BT Quad Input OR Gate 1 1.45 1.45 LM393 Comparator 1 3.00 3.00 Casing and Support 1 14.40 14.40 Electronic Components & PCB 1 30.00 30.00

EyeMod PIC16F627 Microcontroller 4 11.21 44.84 (× 4) Nordic nRF401 Transceiver 4 11.54 46.16

DS18B20 1-wire Digital Thermometer 1 5.14 5.14 Casing 4 9.26 37.04 Electronic Components & PCB 4 20.00 80.00

TOTAL

$540.51

The total cost includes the costs of ParentMod, ChildMod and four EyeMods

(2×LocalEye, PointEye and SmartEye) which is AU$540.51. This is quite expensive

for a child minding system. The cost will be significantly reduced if the components had

been purchased in bulk.

Table 5: BlueNanny Budget


34.

7.1.5 Data Rate Table 6 summarises the data rate of all wireless communication in BlueNanny.

Module → Module Data Rate

ParentMod → ChildMod 56.6kbit/s

ChildMod → ParentMod 56.6kbit/s

EyeMod → ChildMod 2.4kbit/s

Selection for the EyeMod to ChildMod data rate is explained in section 5.3. Even

though the maximum data rate for Bluetooth is 721kbit/s, our selected microcontroller�s

(PIC16F876) maximum bit rate with a zero error rate was 56.6kbit/s. All of these data

rates were sufficient in the implementation of BlueNanny. The BlueNanny modules at

illustrated in the Appendix.

Table 6: BlueNanny data rates


35.

7.2 BlueNanny performance Evaluation

BlueNanny provides constant child minding although the range is restricted due to the

inability for the Ericsson Bluetooth ROK modules to transmit reliably for further than

10m. This will therefore affect the audible range for voice communication. To test the

audible range between the ParentMod and ChildMod, simple measuring of distance

between the two Bluetooth devices versus the receiver audibility was conducted.

Figure 16 displays the results of a voice recognition test conducted in an indoor

environment.

The focus of the experiment was on the influence of distance and object obstruction on

voice quality. It was discovered that with obstructions in signal path, Bluetooth

connection could be kept alive for up to 10m. However, audible voice has only a range

of about 12m. At a separation distance of approximately 8m, noise level or cracklings

start to rise. When one Bluetooth unit is totally obstructed from the other Bluetooth

unit, there is an immediate decrease in audible volume. However, there is no increase

Figure 16: Bluetooth voice quality versus distance between units


36.

in noise level until separation distance between the units reaches 8 meters, when the

connection is broken.

The SmartEye module was also put through a number of tests in order to assure

transmission when it reaches a critical temperature. This experiment is conduct by

using an analog thermometer strapped to the smart. This will display the exact

temperature of the surrounding environment. Therefore by using an ordinary hair-

drying, the SmartEye can be issue constant heat. Due to the SmartEye temperature

sensor positioned inside the casing, an external temperature of 47°C did not result in the

SmartEye transmitting. Therefore the SmartEye temperature sensor was tuned done to

40°C in order for it to transmit at a 47°C external temperature.


37.

CHAPTER 8

Future Development

Future development of the BlueNanny design can be implemented by different wireless

communications as technology improves. Using RF ID tags, especially passive RF ID

tags, as beacons could be just one solution. Passive RF tags will not need a battery

power supply, therefore no replacement of batteries will be required. Another solution

could be using Ultra Wide Bandwidth (UWB). UWB technology can provide very fine

range resolution and precision distance and/or positioning measurement capabilities.

This technology could eliminate the need for LocalEyes as distance and location will be

known.

This is not to say that Bluetooth is not adequate source of wireless communication. The

BlueNanny system designed did have the problem of much reduced range. This is

mainly due to the Bluetooth module in use. The latest technology of Bluetooth (Class I)

can provide and reliable link at distances of 70m with the aid of an external antenna.

Technology like this could prove ideal for the BlueNanny design in all house-holds.

A future development in design could be the implementation of a water sensor into the

ChildMod design. This idea was initially suggested, although due to the inability of the

Bluetooth module to transmit underneath water, this idea was scrapped. Although, most

RF communications are possible to transmit underneath water with a great enough

power. Therefore, the inclusion of this feature would prove beneficial to alert parents

before their child drowns.


38.

CHAPTER 9

Conclusion

BlueNanny has applied today�s technology to introduce a new dimension to

childminding at home. It provides constant awareness of children with the integration

of latest technologies. With the application of BlueNanny (Bluetooth-based assistant

nanny) there is always an eye on the children.

Bluetooth technology is used in this project to provide a secure, cheap and power

efficient solution to childminding techniques. RF beacons are implemented into

BlueNanny to provide a reliable location method. Communication between the network

of RF beacons and Bluetooth links will constantly monitor the location of a child. This

proves beneficial for the supervision task and acts as an assistant to parents for their

childminding responsibilities.

This thesis portrayed the hardware aspect of the BlueNanny system by accompanying

its design solutions. It delved into the development of Bluetooth voice communication

and BlueNanny module hardware and also provides the software concepts used for

hardware integration. With current trends in market growth, the demand for Bluetooth

applications is set to increase. With future revisions of Bluetooth increasing range and

number of supported devices, BlueNanny has the potential to be incorporated into large

scale uses, such as in hospitals, kindergartens and retirement villages.

The final product proved to meet all specifications stated in the thesis proposal. With

numerous innovative features displayed. BlueNanny has entered several competitions,

and not only enthrals household parents; it has been notice by computer design

professionals worldwide.

References Dimitri Peter Andronikos

39.

References

[1]. Summary Statistics Chirpp Database, 1999, �Where The Injury Occurred�,

http://www.hc-sc.gc.ca/pphb-dgspsp/injury-bles/sscd99-spds99/sum1999e.pdf [Accessed 15/10/02]

[2]. Digital Angel Corporation, 2002, �Digital Angel Website�, http://www.digitalangel.net [Accessed 15/10/02] [3]. Carbug, 2002, �Kidbug Website�,

http://www.carbug.co.uk/kidbug.htm [Accessed 15/10/02]

[4]. IEEE Computer Society, 2002, �CSIDC 2002�, http://www.computer.org/CSIDC/ [Accessed 15/10/02] [5]. Bluetooth.com, 2002, �Bluetooth Core and Profiles specifications, v1.0b.�,

http://www.bluetooth.com/pdf/Bluetooth_11_Specifications_Book.pdf [6]. Far Eastern Economic Review, 2002, �Young Inventors Awards�, http://www.feer.com/misc/young.html [Accessed 15/10/02] [7]. Shih, Z, Volume 1, 2002, �BlueNanny � Child Monitoring System�. [8]. Hardcastle, A. G, Volume 2, 2002, �BlueNanny � Child Monitoring System�. [9]. MC145483 Documentation, 2002, �Motorola Website�.

http://e-www.motorola.com/brdata/PDFDB/docs/MC145483.pdf [Accessed 15/10/02]

[10]. NextGen Datacom, Inc., 2002, �Technical Seminars�,

http://www.nextgendc.com/?/seminar_voice_coding.htm [Accessed 15/10/02] [11]. Fox Electronics, 2002, �Crystal And Oscillator Frequency Control�,

http://www.foxonline.com [Accessed 15/10/02] [12]. Microchip Technology, 2002, �Microchip Website�,

http://www.microchip.com [Accessed 15/10/02] [13]. Nordic VLSI ASA, 2002, �Nordic Website�, http://www.nvlsi.no [Last Accessed 15/10/02] [14]. PIC16F627 datasheet, 2002, �Microchip Website�,

http://www.microchip.com/download/lit/pline/picmicro/families/16c62x/40300b.pdf [Last Accessed 15/10/02]

References Dimitri Peter Andronikos

40.

[15]. Balanis, C. A., 1997, �Antenna Theory: Analysis and Design�, New York, Wiley, 2nd Ed. [16]. Parenting.org, 2002, �Burn Safety�,

http://www.parenting.org/archive/precious/safety/Jan02_burn_safety.asp [Last Accessed 15/10/02]

[17]. Maxim, Dallas Semiconductor, 2002, �Maxim Website�,

www.maxim-ic.com [Last Accessed 15/10/02] [18.] Maxim, Dallas Semiconductor, 2002, �DS18B20 Datasheet�,

http://pdfserv.maxim-ic.com/arpdf/DS18B20.pdf [Last Accessed 15/10/02] [19]. Reynolds Electronics, 2002, �1-Wire Temperature Application�,

http://www.rentron.com/PicBasic/one-wire3.htm [Last Accessed 15/10/02] [20]. Dincer Aydin�s Home Page, �LCD Info Page�,

http://www.geocities.com/dinceraydin/lcd/intro.htm [Last Accessed 15/10/02] [21]. PICALL, �P16PRO & PICALL PIC Programmers Official Web Site�,

http://www.picallw.com [Last Accessed 15/10/02]

Appendix Dimitri Peter Andronikos

41.

Appendix

Figure A-1: Voice Codec Schematic


42.

For complete listings of the source code designed and implemented as a part of this thesis, for the EyeMod, contact the author at [email protected]

Figure B-1: EyeMod hardware schematic


43.

Figure B-2: DS18B20 Command flow-chart


44.

Figure B-2: DS18B20 Function flow-chart


45.

For complete listings of the source code designed and implemented as a part of this thesis, for the LCD driver, contact the author at [email protected]

Figure C-1: LCD specifications


46.

Figure C-2: LCD module character display look-up table


47.

Figure D-1: BlueNanny modules hardware view

Documents

Child Monitoring