emergency child guidance system - ecpe senior design...
TRANSCRIPT
Emergency Child Guidance System
Final Report
Team: May 01-03
Team Members:
Abbey Arends
Chris Bloomquist
Lisa DeLashmutt
Karen James
Angela Nystrom
Client Names: Patterson & Lamont
Faculty Advisors: Patterson & Lamont
Date Submitted: April 16, 2001
TABLE OF CONTENTS
TABLE OF CONTENTS.....................................................................................................iLIST OF FIGURES.............................................................................................................iiLIST OF TABLES..............................................................................................................iiIntroductory Materials.........................................................................................................1
Executive Summary..................................................................................................................................1Acknowledgements..................................................................................................................................2Definition of Terms..................................................................................................................................2
Introduction..........................................................................................................................3General Background.................................................................................................................................3Technical Problem....................................................................................................................................4Operating Environment............................................................................................................................5Intended Users and Uses..........................................................................................................................5Assumptions and Limitations...................................................................................................................5
Design Requirements...........................................................................................................6Design Objectives.....................................................................................................................................6Functional Requirements..........................................................................................................................7Design Constraints....................................................................................................................................8Measurable Milestones.............................................................................................................................9
End Product Description....................................................................................................10Approach and Design........................................................................................................11
Technical Approach................................................................................................................................11Technical Design....................................................................................................................................12Testing Description................................................................................................................................14Risks and Risk Management..................................................................................................................15Recommendation for Follow-on Work..................................................................................................16
Financial Budget................................................................................................................16Personnel Effort Budget....................................................................................................17Project Schedule................................................................................................................18Closure Material................................................................................................................19
Evaluation of Project Success................................................................................................................19Commercialization.................................................................................................................................19Recommendation for Additional Work..................................................................................................19Lessons Learned.....................................................................................................................................20Project Team Information.......................................................................................................................21Summary.................................................................................................................................................22References..............................................................................................................................................22
Appendix A – User’s Manual..........................................................................................A-1Appendix B – TRF4900...................................................................................................B-1Appendix C – TRF6900...................................................................................................C-1Appendix D - Microphone-to-Transmitter Schematic………………………………….D-1
i
LIST OF FIGURES
Figure 1 – ECGS Design......................................................................................................4
Figure 2 – Alarm sensor………………………………………………….………………12
Figure 3 – Central transmitter……………………………………………………………13
Figure 4 – Battery-powered light………………………………………………………...14
Figure 5 – Rechargeable light……………………………………………………………14
Figure 6 – Project schedule...............................................................................................18
LIST OF TABLES
Table 1 – Financial Budget...............................................................................................16
Table 2 – Personnel Effort Budget....................................................................................17
ii
Introductory Materials
Executive Summary
The goal of this project is to design, build, document, and test an emergency child
guidance system (ECGS). The system triggers from the sound of a common smoke alarm
and will guide children to safety during a household fire. The ECGS targets children
between the ages of two and eight years. This system will help reduce the number of
deaths during household fires.
There are many deaths every year because of household fires. The majority of casualties
in fire-related deaths are children. One of the reasons for this is because children panic in
emergency situations. For example, when a smoke alarm triggers, it produces a very loud
sound, which often terrifies young children. Terrified children all react differently.
Some simply pretend that the fire is not happening. Others hide in their closet to escape.
The goal of the ECGS is to provide a consistent and safe route of exit for the child during
the fire.
The ECGS was implemented using a smoke alarm, alarm sensor, central transmitter,
voice recording, and a set of lights along an escape route. One of the smoke alarms
detects the fire and emits the high-pitched sound. One or more of the alarm sensors pick
up the sound and send a signal using the some frequency to the central transmitter. The
central transmitter’s logic determines where the fire was sensed and outputs the signal to
light up the correct set of lights. The lights receive the signal from the central transmitter
and light up the route leading to the safest exit. As the child passes each light and presses
it, a pre-recorded message to aide in the exit will be played. Refer to Figure 1 for a
diagram.
The entire ECGS was not fully implemented, but an operating prototype was
implemented. The ECGS prototype includes a microphone-to-transmitter combination.
An amplifier was used to increase the frequency of the sound of the smoke detector.
1
Then a diode and an integrator were added to make the signal produced stay large over an
extended period of time. The reason for this is to differentiate the noise of the detector
from other loud noises such as a screaming child or loud music. Lastly, the non-inverting
comparator was added to make the on/off switching more assured. For the receiver-to-
light combination, a simple relay was used to switch the lights. As a result of the
prototype, a demonstration will be given to the industrial review panel.
Acknowledgements
The May 01-03 group would like to acknowledge Dr. Lamont and Dr. Patterson for the
extensive amount of advice, research, and technical support provided throughout the
ECGS project.
Definition of Terms
ECGS – Emergency Child Guidance System
Smoke alarm – The common, everyday smoke alarm in households.
Alarm sensor – It is activated by the sound of the smoke alarm and sends an
analog signal to the central transmitter.
Central transmitter – Contains the logic, transmitter for lights, radio transmitter,
recording device, and voice recording equipment.
Voice recording – The personalized message from the central transmitter.
System – The entire ECGS.
Devices – Refers to one of the following: alarm sensor, central transmitter, and
lights.
2
Introduction
General Background
Many children die during household fires because of the lack of guidance during an
emergency situation. This system, which triggers off of the sound emitted from a smoke
alarm, will use a pre-recorded voice and a path of lights to direct the child to safety. The
devices included in the system are alarm sensors, a central transmitter, battery powered
lights, and rechargeable lights. The alarm sensors will be mounted near the smoke alarms
already in the household. The central transmitter will be placed away from the smoke
alarms, and the lights will be strategically placed in a path routing a safe exit. The system
is outlined in the Figure 1 and described thoroughly in the technical design.
3
Bedroom #1
R #1
R #2
R #5
Central transmitter
Alarm sensor #2
R #3
R #4
R Route
Figure 1 – ECGS Design
Technical Problem
As seen in Figure 1, one of the smoke alarms detects the fire and emits the high-pitched
sound. One or more of the alarm sensors pick up the sound and send a signal using a
particular frequency to the central transmitter. The central transmitter’s logic determines
where using the frequency of the signal received from the alarm sensor sensed the fire. It
then outputs the correct of lights to turn on using the appropriate frequency. The route of
Bedroom #2
R #1, R # 2
R #1
R #2
Front Door
Back Door
R #6
Alarm sensor #1
Smoke alarm #1
Smoke alarm #2
Touch light
Bedroom
Frequency #1
Frequency #2
(Additional alarms and sensors)
Frequency #3
4
lights receive the signal from the central transmitter and light up accordingly. If pressed,
each light plays a pre-recorded message explaining how to exit the house safely.
Operating Environment
The central transmitter will be located where fires are less likely to reach and will be in a
fire-retardant case. The casing for all of the devices will be waterproof for customers
owning a fire-activated sprinkler system. Also, the casing must be somewhat durable in
the event of explosion or destructive conditions. During the loss of power, the system
will continue normal operation.
Intended Users and Uses
USERS - The product targets the general public with 2-8 year old children living in the
home. The ECGS may also be modified for use in daycares, nursing homes, etc.
USES - The system will calmly communicate with the child during a household fire,
directing the child to safety.
The ECGS should not be used as a replacement for other fire-safety measures, and the
system must be rehearsed with the intended user.
Assumptions and Limitations
Assumptions:
The customer will need to have at least one smoke alarm installed
When children are not under adult supervision, they are assumed to be located in
their bedroom or playroom. This must be assumed to ensure that the path of
lights will lead them from this room to a safe exit.
5
Limitations:
The success of the system depends on the reliability of the smoke alarm.
The smoke alarm and the system components must all be checked regularly to see
if the batteries are charged, and they must be checked regularly for the low-
battery light.
The customer must understand that at some point during the fire, it will be
impossible to prevent the system from succumbing to the fire.
The child may not respond to the voice or light guidance.
The system does not guarantee to save the child’s life.
The lights must be visible in the smoke.
There might not always be a safe route.
If there is a false alarm, the ECGS will react as though there were a real fire. This
will provide the children a chance to practice exiting safely.
Design Requirements
Design Objectives
(Please refer to the figures in the technical design.)
6
Functional Requirements
Smoke alarm
Batteries: It is assumed that most smoke alarms require batteries for adequate
power.
Alarm sensor
Batteries: It is assumed that the alarm sensor will require batteries for adequate
power.
Sound receiver (microphone): The alarm sensor’s receiver picks up any audible
sound within range.
Transmitter: A transmitter will send an analog signal to the central transmitter to
activate the rest of the system.
Central transmitter
Batteries: It is assumed that the central transmitter will require batteries for
adequate power or an AC power supply with a battery back-up.
Signal receiver: The central transmitter’s receiver will pick up the analog signal
sent by an alarm sensor.
Signal transmitter: The central transmitter will transmit an analog signal to the
touch lights, turning on the appropriate path.
Logic: The logic will control the internal logic for selecting the correct route of
exit.
Touch lights
Batteries: Batteries are needed to power each light.
7
Signal receiver: A signal receiver will be needed in every light to pick up the
signal generated by the central transmitter.
Recording device: Each light will have a recording device. This device will
encompass the functions of a common recorder such as play, record, and stop.
Users will be able to customize their own message in order to fit their needs.
Light bulb: A small but bright bulb will light the casing of each touch light.
Logic: Simple logic will control the recording device, light bulbs, and receivers.
Design Constraints
Temperature: The ECGS must operate during a fire.
Water: The system must be waterproof.
Lightweight: The system must be able to stay mounted on the ceiling or wall.
Durability: To withstand volatile fire conditions, the system must be durable.
Power Loss: The system must be battery powered so that it will still operate under
power outages.
Location: The alarm sensor will need to be within a few inches of the smoke
alarm. The touch lights should be mounted as close to the floor as possible, and
less than ten feet apart from each other. They are placed near the floor to keep the
child low to avoid smoke inhalation.
8
** IT IS ASSUMED THAT UNDER EXTREME FIRE CONDITIONS, ALL OF THE
DEVICES WILL EVENTUALLY FAIL.
Measurable Milestones
(GREATLY EXCEEDED, EXCEEDED, MET, ALMOST MET, TO BE MET, FAILED
TO MEET)
Learn the functions, operations, and features of the household smoke detector.
EXCEEDED
Research fire departments, smoke detector companies, child psychologists, and
other knowledgeable sources.
GREATLY EXCEEDED
Finalize the design specifications.
MET
Explore all microcontroller options to select the most suitable for the system.
MET
Choose the most accommodating power source.
MET
Assure compatibility of the interface of the microcontroller with the smoke
detector.
MET
Complete the design of the speakers and recordable device.
MET
9
Implement system components.
MET
Integrate system
MET
Test and re-evaluate the system.
MET
Debug and finalize the operation of the product.
ALMOST MET
Document.
ALMOST MET
End Product Description
The end product for this project contains a system designed to guide 2-8 year old children
to safety during a household fire. The alarm sensor will be activated by the sound of the
smoke alarm, and send a signal to the central transmitter. The central transmitter will
send out signals to the appropriate lights. The lights, along with the recorded message,
will then guide the children to safety. The standard package is designed for one route and
one smoke alarm. It includes one alarm sensor, one central transmitter, and eight lights.
Additional components will be available to modify the system for more escape routes and
smoke alarms.
10
Approach and Design
Technical Approach
Before implementation, substantial information was gathered from professional sources
such as Mr. Fred Malven, Nevada’s Fire Chief; Mr. George Oster, Ames fire-training
center; a child psychologist; detector/alarm companies; and a potential customer to aid in
the development. These sources provided input on the location, sound, and installation of
the device. The questions asked and most common answers are as follows:
1. What color should the lights be?
Bright and easy to see in smoke – (white)
2. How far apart from each other should the light be?
About 5 feet
3. What distance can each device be from the smoke alarm?
Alarm sensors about 6 inches
4. Should the alarm sensors detect a signal or the sound from the smoke alarm?
Detect the sound b/c of liability issues
5. How much heat can the devices take before they fail?
Won’t really matter since at that point of operation, the child will not take that
path anyway.
6. How much time for escape is there in a fire?
Depends on the smoke and carbon monoxide
7. What should be said in the message and how loudly should it be played?
Soothing message to ease the child out of the house
8. What age children should this target?
2-8 years old
9. Is the overall concept a good one?
Wonderful!!
10. Improvements?
Maybe some add-ons: a smart system, ropes or ladders, etc.
11
The information gathered from these sources was applied to the design and
implementation of the child guidance system. Ideally, multiple smoke alarms and sensors
can be implemented to choose the safe exit of a child. This involves the sensors
triggering the central transmitter to activate different routes and voice recordings for the
appropriate situation.
Before deciding which components to use on the prototype for the ECGS, car
transmitters/receivers were researched, as well as many other commercial parts. In the
end, remote control car transmitters/receivers were used in the implementation of the
prototype. The schematic started with a microphone-to-transmitter combination. An
amplifier was used to increase the frequency of the sound of the smoke detector. Then a
diode and an integrator were added to make the signal large over an extended period of
time. The reason for this is to differentiate the noise of the detector from other loud
noises such as a screaming child or loud music. Lastly, the non-inverting comparator was
added to make the on/off switching cleaner. For the receiver-to-light combination, a simple relay was used to get to the light. Refer to Appendix D for the schematic design.
Technical Design
(Please refer to Figure 1 for a picture of the technical design of the ECGS.)
Smoke alarms – The system would consist of the generic smoke alarms that most people
have in their houses and apartments. The smoke alarms would be used in order to activate
the ECGS. The alarm sensors would pick up the sounds from the smoke alarms and
activate the system.
Alarm sensors – For every smoke alarm, there would be an alarm sensor. The purpose of
the alarm sensor is to detect the noise from the smoke alarm. Then, the alarm sensor
would send a signal to the central transmitter. If more than one smoke alarm is sounding,
then all alarm sensors detecting smoke alarm sound would send signals to the central
12
transmitter. The signals sent by each alarm sensor would all be of the different
frequencies so that the central transmitter could interpret the location of the fire. The
alarm sensors are further explained in Figure 2 below.
Figure 2 – Alarm sensor
Central transmitter –The central transmitter would receive the signals from the alarm
sensors. Through the logic programmed in C, the central transmitter would be able to
detect which smoke alarm was activated. Thus, it would be able to determine whether the
child should follow the route that leads to the front door, the back door, or the window of
the child’s bedroom. Also, the central transmitter would send the proper signals to
activate the lights and the personalized voice recordings. Each light would have a
receiver located within. The signal sent out by the central transmitter would have a
different frequency for each light route. Thus, the correct route of lights would light up.
Figure 3 below outlines the central transmitter.
Figure 3 – Central transmitter
Transmitter – sends signal to central transmitter
Receiver – gets signal from smoke alarms
Transmitter – sends signal to the correct light path
Receiver – gets signal from the alarm sensors
Logic – determines where fire is and which exit route to activate
13
Rechargeable batteries
The voice recording and playing equipment
Lights – Each of the lights would contain a receiver in order to get the message sent from
the central transmitter. Thus, the appropriate escape route would light up in order to guide
the child to safety. The receivers in the light would be powered two ways. The first
option is a battery only power source. The other is a rechargeable battery that would
definitely be the more efficient option in the long run. Also, each light contains the
sound recording and playing equipment. When the child pushes the light, the appropriate
message would be played in order to lead the child safely out of the house while avoiding
the fire. All personalized messages would be recorded on the device located within the
lights. The two types of lights are explained in Figure 4 and Figure 5 below.
Figure 4 – Battery powered light (rear view) Figure 5 – Rechargeable light (rear view)
(Please see Appendices B & C for the technical description of the transmitters and
receivers to be used for the ECGS.)
Testing Description
Smoke alarms tested for:
o Proper functionality – light a match to ensure the alarm sounds
o Power source – push the test button
Results - The smoke alarm sounded when a match was lit underneath, and the test
button responded correctly when pushed.
Batteries – 2 AA batteries
14
Alarm sensors tested for:
o Reception of the smoke alarm sound – sound the smoke alarm using the
test button
o Transmission to the central transmitter – check to see the central
transmitter received the signal
o Power source – check batteries on a regular basis
Results - There are no alarm sensors in the prototype, thus no tests were
performed.
Central transmitter tested for:
o Reception from alarm sensors – check to see the central transmitter
received the signal
o Proper logic in the sensors – place match at back door smoke alarm to see
if route is lit to escape at front door
o Transmission to the lights – check to see if the proper route lit up
o Power source – check batteries on a regular basis
Results - There is no central transmitter in the prototype, thus no tests were
performed.
Lights and recordings tested for:
o Power source – check batteries on a regular basis
o Reception of the signal – check to see whether proper route of lights is lit
o Playing of the recorded message – when the light is pressed, a message
plays.
Results - The message plays when pressed and the lights turn on as appropriate.
Risks and Risk Management
Loss of team member – The rest of the team would have to work harder in order
to make up for the loss, and at least two people need to know every aspect of the
project.
15
Slow or non-delivered parts – The team would contact the advisors and clients for
assistance.
Higher complexity than originally intended – The team would work with the
advisors to simplify the project or make a prototype.
Change of requirements – The team would have to remain flexible and adjust to
the necessary changed.
Reliability of vendor products – In the event of poor products, the team must re-
order the products to get some that work properly.
Recommendation for Follow-on Work
A commercialized version of this product is a great idea. It would help save lives! But,
the liability of the system is very great because of this. With some more work, some
enhancements on the prototype could be done in order to make the system as close to
being commercialized as possible.
Financial Budget
The cost of the project can be seen below in Table 1. The costs are based on the amount
each product cost to be ordered, shipped, and delivered or store-bought.
16
Table 1 – Financial BudgetItem Original Estimated Cost Revised Estimated Cost Actual Final Cost
Poster $50.00 $36.00 $36.00
Digital Voice Recorder $20.00 $9.99 $9.99
Remote Control Truck N/a N/a $7.98
Microphone N/a N/a $2.10
Wires and Circuitry $20.00 $15.00 $10.00
Push Lights $21.00 $10.00 $10.00
Batteries N/a $10.00 $20.00
Receiver Chip N/a $0.00 $5.00
Transmitter Chip N/a $0.00 $5.00
Casing $10.00 $15.00 $30.00
Labor $0.00 $0.00 $0.00
Speaker System $30.00 $0.00 N/a
Total cost $156.00 $95.99 $136.07
Personnel Effort Budget
The time that each member spent on the project can be seen below in Table 2. Both the
estimated and actual numbers are in the table.
Table 2 – Personnel Effort Budget
Personnel Original Estimated Effort Revised Estimated Effort Actual Estimated Effort
Abbey Arends 94 110 130
Chris Bloomquist 102 105 132
Lisa DeLashmutt 109 110 133
Karen James 110 100 119
Angela Nystrom 107 120 136
Total estimated effort 522 545 650
17
Project Schedule
The Gantt chart (Figure 6) displays the schedule of the project over the course of two
semesters, starting in September and going through May. The chart shows the major
milestones. The project plan milestone was completed on September 24, 2000. The next
milestone, the project poster, was completed on October 29, 2000. The design document
was completed on November 28, 2000. The next major milestone is the implementation
of the project design. It was completed on March 25, 2001. Next, the final report was
compiled by April 16, 2001. Finally, the industrial review would be given to the panel on
April 25, 2001.
Figure 6 – Project Schedule
18
Closure Material
Evaluation of Project Success
The ECGS has a fully operating prototype. When a match is lit under the smoke alarm,
the system is activated and the lights are turned on. There is also a voice recording that
plays when the lights are pushed. The commercial ECGS is not fully operating, but the
group feels it could be in the near future if the funding and time were allowed to
implement the appropriate transmitters and receivers.
Commercialization
Although it was initially believed that the ECGS was a marketable product, many
adjustments would have to be made for it to be a viable option. There are too many weak
links in the system that would have to be explored further. In particular, the transmitters
and receivers would need to be less expensive. Another huge challenge is the fact that
human lives depend on the ECGS, so the liability would be enormous. Yet another
constraint is having multiple routes, which would require the ECGS to cover a large area.
Recommendation for Additional Work
Build the actual ECGS, rather than the prototype.
Explore the other options. For example, multiple routes and multiple smoke alarms.
Install the ECGS in a home and run a test case.
Incorporate add-on features such as ropes or other fire-safety devices.
19
Lessons Learned
What went well?
May 01-03 worked very well together.
Individual member’s strengths were utilized through project division.
The project progressed throughout the year and developed with the team.
What did not go well?
The search for the perfect parts did not go well.
Many ideas for the transmitters and receivers were tested and rejected.
As the project developed, new obstacles presented themselves.
What technical knowledge was gained during the project?
Extensive knowledge of transmitters and receivers
Internal logic of transmitters and receivers
Electrical circuitry
Interference among transmitters and receivers
Power sources
What non-technical knowledge was gained during the project?
Labor division
Time management
Meeting milestones
How to prorate your time over an entire year
Team work
Staying active in between milestones
Networking
Finding outside resources
20
Project Team Information
Team Members:
Angela Nystrom Lisa DeLashmutt
1123 N. 3rd Street 425 Welch Avenue Apt #106
Ames, IA 50010 Ames, IA 50014
292-8033 268-1581
[email protected] [email protected]
EE CprE
Abbey Arends Karen James
614 Billy Sunday Road Apt #103 1300 Gateway Hills Apt #110
Ames, IA 50010 Ames, IA 50014
233-5318 292-8167
[email protected] [email protected]
CprE CprE
Christopher Bloomquist
258 N Hyland Apt #17
Ames, IA 50014
292-3611
CprE
21
Client and Faculty Advisors:
Dr. John W. Lamont Dr. Ralph Patterson III
Iowa State University Iowa State University
324 Town Engineering 326 Town Engineering
Ames, IA 50011-3230 Ames, IA 50011-3230
294-3600 294-2428
Fax: 294-6760 Fax: 294-6760
[email protected] [email protected]
Summary
This emergency child guidance system will help save the lives of children during a
household fire. This system will keep children calm while directing them to safety. It
will incorporate a familiar voice aiding the safe exit of the child from the house.
References
Mr. Fred Malven, Nevada’s Fire Chief
Mr. George Oster, Ames fire-training center
22
Appendix A – User’s Manual
USER’S MANUALEmergency Child Guidance System
Overview:
The Emergency Child Guidance System (ECGS) was designed in order to help children
safely escape from a household fire. When your smoke alarm sounds, the ECGS will
light up a path of lights for your child to follow that will help guide them to safety. (You
may purchase additional lights at different frequencies that will allow the system to work
for multiple exits.) Part of the system will detect where the fire is located. Depending on
the location of the fire, the appropriate path of lights will light up, thus leading your child
to safety. In addition, each light will have your voice recorded on it. Thus, the child can
push the light at any time to hear your voice guiding them to safety. With routine
practice, this system will greatly assist your children in the exiting of your house during a
fire.
Before you begin:
First off, in order for the ECGS to operate properly, you must make sure that you have a
smoke alarm already installed in your home. They are just generic household smoke
alarms that make a loud noise to sound the alarm. The ECGS is activated when at least
one of your smoke alarms sound. Therefore, without smoke alarms, the ECGS will not
work.
1
6 2
Before you begin any assembly or installation of the Emergency Child Guidance System,
you should make sure that your kit includes the following:
Alarm Sensors
Central Transmitter
6 battery powered lights and 2 rechargeable lights
The Alarm Sensor
The alarm sensor plays a critical role in the operation of your system. When your smoke
alarm sounds the alarm, the alarm sensor will sense the sound and send a signal to the
central transmitter.
The Central Transmitter
The central transmitter transmits a signal that will turn on the path of lights. If you opt
for the multiple exit plan, then this is where the location of the fire will be determined,
thus allowing the appropriate path to light up.
2
Smoke Alarm
Alarm Sensor
Ceiling
The Lights
The lights form the path that will help guide your child to safety. They will be placed
near the ground so that your child will have to crawl, thus avoid the smoke. Also, each
one is equipped with a voice recording that will help to guide them out the door when
activated. The lights are “push” lights, so in order to play the recording in each light, all
your child will have to do is push the light.
You may wish purchase more lights to provide for a clearer exit route. And, most
importantly, the lights come in difference frequencies. This will allow the ECGS to
operate for different exits. When purchasing additional lights, you should check the
frequencies clearly labeled on the box. If you want to provide paths for more exits, make
sure you have enough lights of each frequency. If you only want to set up the ECGS for
one exit path, make sure that all of the lights are the same frequency. (Each light is color-
coded. This color-coding is also used on the box.)
Installation of the alarm sensor:
Since the alarm sensor picks up the noise from the smoke detector, it will work best when
placed near the smoke detector. Therefore, you should mount the alarm sensor on the
ceiling within six inches of your smoke detector. You will need an alarm sensor for
every smoke alarm.
Installation of the central transmitter:
The central transmitter is also mounted on the ceiling. It must be located within 100 feet
of the alarm sensor. The central transmitter will be able to receive the signal when it is
around the corner from the alarm sensor and smoke detector; however, it is best to place
3
Smoke Alarm
Alarm Sensor
Ceiling
Central Transmitter
50 ft
the central transmitter within 50 feet of each alarm sensor. It does not need to be in the
same room as the smoke alarms or alarm sensors.
Recording a message on each light:
Every light has a prerecorded message. Press the light to hear the message. The default
says, “Please remain calm and crawl forward to the next light.” If you choose, you can
personalize every light’s recording. For example, if the child needs to turn a corner, you
may say so in the message. Each message must be under 15 seconds long. Each light
could contain a different message if needed. If the message needs to be repeated, the
light can simply be pressed again.
Each light has a button located on the back labeled “Record.” To customize your own
message, press and hold the record button. Hold the light near your mouth so that the
speaker can pick up your voice. Record your message. Release the record button when
finished. To listen to your message, simply push the light just as your child would do
during a fire.
Installation of the lights:
The lights should be placed just off the floor level about 5 feet apart. This will encourage
your child to crawl on the floor, thus avoid the smoke. Make sure that the lights lead to
an exit. Also, they need to be close enough together that the child does not get lost or
confused. Thus, if the child needs to turn a corner, for example, make sure that there are
lights on both sides of the corner to ensure that the child will make the appropriate turn.
4
Floor
LightLightLight
5 feet 5 feet
When installing the lights for different exits, make sure that there are ample lights for
every path. For example, if the same path is followed for a while, there must be lights of
every frequency. Only one path will light up.
Important Reminders:
The ECGS will not work unless your smoke alarm is properly operating. Thus, it is
important to test the batteries in your smoke alarms at least once a month. In addition,
when the battery tests are being performed on the smoke alarms, you should also test the
batteries in the alarm sensors, the central transmitter, and the lights. If these are not
working, the entire system may fail!
Also, it is very important to perform routine training procedures with your children.
When you test the smoke alarms, if all the batteries are working in each of the system
components, the ECGS will be activated. This would be one of the best times to practice
with your children. Explain to the children what is happening and guide them through
the path of lights. For example, explain how crawling on hands and knees is important
for staying low to the ground to avoid smoke inhalation.
Contact Info:
If you have any questions or concerns, please contact our company at the following
address:
Mr. Important
Our Company
1234 This Street
Town, State Zip
5
Appendix B – TRF4900
TRF4900: Single-Chip RF Transmitter
Product Description
The TRF4900 is a programmable chip designed for linear (FM) or digital (FSK) RF
transmissions in a transmitter/receiver combo. It has a frequency operation range of 850-
950 Mhz, and is designed for affordability in regard to power consumption and monetary
costs. It should also be noted that the two operation modes, Mode0 and Mode1 have ultra
fast switching between the pre-programmed settings. A complete block diagram of the
TRF4900 can be seen below.
1
Block Diagram Components
There are five main components that comprise the TRF4900 chip. These components are
the phased-locked loop (PLL), voltage-controlled oscillator (VCO), serial interface, direct
digital synthesizer (DDS) & power-down logic, and the power amplifier. A full
description of these will be discussed in this section.
Phased-locked Loop (PLL):
The purpose of the PLL is two fold. Its main job is to multiply the output frequency of
the DDS. Its secondary goal is to filter out any unwanted excess signals generated by the
DDS output, so that noise is minimal. To accomplish these tasks, the PLL works directly
with the outputs of both the VCO and DDS. A phase detector (PD) and a frequency
2
acquisition aid (FD), which includes two charge pumps, are also included. The charge
pumps allow for a desired frequency to be “locked in” once achieved.
The pins connected to the PLL are pins 1-3, 6, 23, and 24. Pins 1 (PD_OUT1) and 24
(PD_OUT2) are the pins used for the charge pump output of the phase detector. When
pin 1 is activated, the PLL is in its locked condition, while pin 24 is activated for the
unlocked condition. Pin 2 (PLL_VCC) is used to power the PLL with a supply voltage.
Pin 3 (PD_SET) is used to regulate the current setting of the charge pump. When a
resistor (R_PD) is connected here, the nominal charge pump current can be set. Pin 6
(PLL_GND) is used to simply ground the component. Finally pin 23 (LOCKDET) is the
lock-detect output, which is active in the high state (PLL locked when LOCKDET = 1).
Voltage-Controlled Oscillator (VCO):
The singular purpose of the VCO is to control the signal sent to the PLL for further use.
It does this by using a modified Colpitts oscillator architecture with an external resonant
circuit. To allow for a wide range of Q-factors, the internal bias current network works to
adjust the signal amplitude of the VCO.
The pins connected to the VCO are pins 4 and 5. Pin 4 (VCO_TANK1) is left open if an
external VCO is used rather than the one within the TRF4900. Pin 5 (VCO_TANK2) is
used to take in the signal of an external VCO.
Serial Control Interface:
The serial control interface is used to program the TRF4900. It is comprised of many
smaller components such as a logic component, a 24-bit shift register, a 3-bit address
register, an address decoder, and five latches A-E.
The pins connected to the serial interface are pins 8-12. Pin 8 (CLOCK) is the most
important in this system, since it sets all of the serial control interface components in
3
motion. The input of the clock signal must go from low to high, so that the logic value
from pin 9 (DATA) is written to the 24-bit shift register. Pin 10 (STROBE) is active in
the high state as well. When active, it loads the programmed information into the
appropriate latch. It should be noted that when the STROBE pin is high, the DATA and
CLOCK pins must both be low, since the two signals are asynchronous.
As mentioned earlier, the main goal of the serial control interface is to program the
TRF4900. This is done when the four control words, which are 24 bits in length, are sent
from the shift register to the latches. If there are changes made within words, only the
selected word needs to be changed, rather than the set of four being scrapped. Although
there are five latches, only latches A-D should be used in normal operation. Latch E is
utilized only for test purposes, so activating it activates the test modes within the
TRF4900. The only way to exit the test mode is by both switching pin 18 (DIG_VCC)
on and off, and by clearing the E-latch. Proper power up of the TRF4900 should include
clearing the E-latch each time the VCC power is applied, so that the test mode is never
inadvertently activated.
The final two pins are pins 11 (MODE) and 12 (STDBY). The MODE pin is simply used
to select between the MODE0 and MODE1 states of the serial interface, which dictates
how the A-D latches are programmed. The STDBY pin is active in the low state, when
STDBY = 0. When active, the contents of the control registers are valid and can be
programmed via the serial control interface.
Direct Digital Synthesizer (DDS):
The direct digital synthesizer (DDS) is used to create a sine wave signal into a digital
one. The motivation for doing this ranges from faster lock times, to higher precision, to
wider frequency ranges, and even to higher levels of software programmability. The
components that make the DDS work are the 24-bit and FSK frequency deviation
registers, an 11-bit digital to analog converter (DAC), a sine shaper, a low-pass filter, and
a logic component that decides if the synthesizer is in mode 0 or 1.
4
The general explanation for how these components work is as follows. The DDS creates
an analog sine wave by using an N-bit adder that counts up from 0 to 2N. Each number in
the n-bit sequence is used to select the corresponding sine wave value. After this process,
the D to A converter switches the signal from digital to analog, and sends the changed
signal to the low-pass filter, which filters out unwanted signals. It should be noted that
the analog output frequency is also used as a reference point for the PLL, which then
multiplies this frequency by the factor chosen.
The pins connected to the DDS are the shared serial interface pin 11 (MODE), pin 14
(TX_DATA), and pins 16 (XOSC1) and 17 (XOSC2). The MODE pin is again used to
select between MODE0 and MODE1, in order to determine which frequency setting to
use. The TX_DATA pin is used for the digital modulation input for both the FSK and
FM transmission frequencies. This pin is active in the high state, TX_DATA = 1. The
XOSC1 and XOSC2 pins are both used for the reference crystal oscillator connections,
with the previous being the output and the latter being the input. If an external crystal is
not used with the DDS, the XOSC2 pin may be utilized as a single-ended clock input.
Power Amplifier (PA):
The final block diagram component to address is the power amplifier. It only purpose is
to amplify the output signal of the VCO, as shown in the previous block diagram. The
particular PA used in the TRF4900 can actually be programmed via two bits (P0 and P1)
from the serial interface’s D latch. There are many internal control loops in the PA that
work together to set the power output, as well as to minimize the amount of sensitivity
the PA has to various outside sources. These include temperature, load impedance, and
variations of power supplies.
There are three pins connected to the PA, which include pins 20 (PA_VCC), 21
(PA_GND), and 22 (PA_OUT). PA_VCC is used to connect the amplifier to a supply
5
voltage. PA_GND is simply used to ground the device. Finally the PA_OUT is the PA’s
output, which is an open collector output terminal.
Miscellaneous Pins
The pins not mentioned within the block diagram report are pins 7 (DIG_GND), 13 (NC),
18 (DIG_VCC) and 19 (GND). Pins 7 and 19 are simply used as ground for the digital
components and the overall ground for the TRF4900 chip. The DIG_VCC is used to
power the digital components, while NC stands for “no connection”, and is therefore not
used.
6
Appendix C – TRF6900
TRF6900 Single-Chip RF Transceiver
(All information taken from http://www.ti.com)
The TRF6900 single-chip RF transceiver is an integrated circuit intended for use as a
digital transceiver to establish a frequency-agile, half-duplex, bi-directional RF link. It
will be used in the Central Logic Transmitter Unit (CLTU) and in the lights. The
TRF6900 has two fully programmable operation modes, Mode0 (receive) and Mode1
(transmit), which allow extremely fast switching between two preprogrammed settings
without having to reprogram the device. The CLTU will utilize both modes by first
receiving a signal from the detector and then transmitting a signal to activate the lights.
The lights will utilize the ‘receive’ mode of the TRF6900, which will enable the lights to
activate.
The chip is intended for linear (FM) or digital (FSK) modulated applications for the 868
MHz and 915 MHz ISM bands. The single chip transceiver operates between 2.2 V and
3.6 V and is expressly designed for low power consumption. The synthesizer has a
typical channel spacing of approximately 230 Hz to allow narrow-band as well as wide-
band application. Each functional block of the transceiver can be specifically enabled or
disabled via the serial interface.
1
TRF6900 Functional Block Diagram
3
43
20
LOCKDET
31
Direct Digital Synthesizer
DDS_GND
Amplifier
2nd IF
4
44
PLL_VCC
LNA_VCC
MODE
19
1st IF
Amplifier
30
5
45 40
DEM_VCC
LNA_OUT
DDS_VCC
Amplifier
Buffer
LNA_GND
6
46
DEM_TANK
and
MIX_IN
TX_DATA
29
37
Amplifier
7
47
18
Power-Down Logic
MIX_VCC
DIG_VCC
8
48
28
Serial
LNA_IN
MIX_OUT
DIG_GND
Data Switch
DEM_TANK
1
17
9
Interface
LNA_GND
MIX_GND
XOSC1
RSSI_OUT
38
2710
36
PLL
PA_VCC
IF1_OUT
AMP_IN
Power
LPR Amplifier/
11
VCO
IF_GND
AMP_CAP
XOSC2
16
35
12
IF2_IN
Post-Detection
PA_OUT
AMP_OUT
_____
STDBY
26
Amplifier
DEM_GND
15
AmplifierPA_GND
S&H_CAP
IF1_IN
34LNA
13
25
RSSI
PLL_GND
DATA_OUT
RF Buffer
Data
2
22
33
14
PD_SET
DATA
VREF
24
Amplifier
FM/FSK
41
PD_OUT2
CLOCK
VCO_TANK1
21
32
RF Mixer
Demodulator
42
PD_OUT1
STROBE
39
VCO_TANK2
23
LO Buffer
Slicer
Low-Noise amplifier (LNA) (pins 1,2,3,47,48)
The LNA provides a typical gain of 13dB and a typical noise figure of 3.3 dB. Two
operating modes, normal and low-gain mode, can be selected. The normal operation
mode is selected when maximum sensitivity at low input levels is required. If high RF
input levels are applied to the TRF6900, the LNA should be operated in the low-gain
mode. This ensures a minimum of nonlinear distortions in the overall receiver chain.
2
Power Amplifier (PA) (pins 4,5,6)
The PA can be programmed via two bits to provide varying output power levels. Several
control loops are implemented internally to set the output power and to minimize the
sensitivity of the PA to temperature, load impedance, and power supply variations. The
output stage of the PA usually operates in Class-C and enables easy impedance matching.
PA_OUT, terminal 5, is an open collector output terminal.
Phase-Locked Loop (PLL) (pins 7,8,9,10,11,12)
The PLL multiplies the direct digital synthesizer (DDS) output frequency and further
suppresses the unwanted spurious signals produced by the DDS. Pins 9 & 10 are charge
pumps used for locking to the desired frequency; one for coarse tuning of the frequency
differences, and one for fine tuning of the phase differences. Pin 11 is the lock detect
output and is active high.
Voltage-Controlled Oscillator (VCO) (pins 13,14)
The VCO drives the internal PLL and PA. A typical level of –10dBm should be applied.
Direct Digital Synthesizer (DDS), power-down logic (pins 15,16,17,18,19,20,21,23,24)
In general, the DDS is based on the principle of generating a sine wave signal in the
digital domain. Benefits include high precision, wide frequency range, a high degree of
software programmability, and extremely fast lock times. The DDS constructs an analog
sine waveform using an N-bit adder counting up from 0 to 2^N in steps of the frequency
register, whereby generating a digital ramp waveform. Each number in the N-bit output
register is used to select the corresponding sine wave value out of the sine lookup table.
After the digital-to-analog conversion, a low-pass filter is necessary to suppress unwanted
spurious responses. The analog output signal can be used as a reference input signal for a
3
phase-locked loop (PLL). The PLL circuit then multiplies the reference frequency by a
predefined factor.
Ground (pin 22)
Ground for the TRF6900
Serial Interface (pins 25,26,27)
A 3-wire unidirectional serial bus (CLOCK, DATA, STROBE) is used to program the
TRF6900. The internal registers contain all user programmable variables including the
DDS frequency setting registers as well as all control registers. The serial interface
consumes virtually no current and it can be programmed in active as well as in standby
mode. The control words are 24 bits in length. To fully program the TRF6900, four 24-bit
words must be sent: the A-, B-, C-, and D-word. A-word handles the programming of
DDS_0. B-word handles the programming of DDS_1. C-word handles the control
register for PLL, data slicer, and Mode1 settings. D-word handles the control register for
Modulation and Mode0 settings.
Data Slicer (pins 28,29)
The data slicer is fundamentally a comparator. The data slicer provides binary logic level
signals, derived from the demodulated and low pass-filtered IF signal, that are able to
drive external CMOS compatible inputs. Pin 28 is the digital output of the data slicer and
is active high. Pin 29 is the connection for sample and hold capacitor for the data slicer.
This capacitor determines the integration time constant of the integrator while in the
learning mode.
4
Low-Pass Filter (LPF) Amplifier/Post-Detection Amplifier (pins 30,31,32)
The low-pass filter amplifier/post-detection amplifier is configured to operate as a
current-to-voltage amplifier and may be used to realize a low pass filter for post
detection. Pin 31 is the connection for LPF amplifier/post-detection amplifier
capacitor/resistor used to reduce the internal low pass filter frequency and to adjust the
post-detection gain.
Receive Strength Signal Indicator (RSSI) (pin 33)
The RSSI provides a voltage at pin 33 that is proportional to the RF limiter input lever.
Because of its ultra fast response time, the RSSI can easily be used as an amplitude-shift
keying (ASK) or on/off keying (OOK) demodulator for data rates up to 100kBit/sec.
FM/FSK Demodulator (pins 34,35,36,37,38)
The demodulator is intended for analog (FM) and digital (FSK) frequency demodulation.
It consists of a quadrature demodulator with an external LC tank circuit. A variable
inductor, internal to the TRF6900, operates in parallel with the external tank circuit, and
is used to adjust the external tank circuit’s resonant frequency.
Intermediate Frequency (IF) Amplifier (pins 39,40,41,42)
The IF amplifiers compensate for losses caused by a ceramic filter and increase receiver
selectivity.
RF Mixer (pins 43,44,45,46)
The RF mixer performs frequency translation of the carrier signals.
5
Appendix D – Prototype Schematic
Prototype Schematic
1