1. adapted hungry, hungry hippos game · adapted hungry, hungry hippos game 1.1 introduction when...
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1. Adapted Hungry, Hungry Hippos Game
1.1 Introduction
When creating the adapted Hungry, Hungry Hippos device the main concern that needs to be
considered is the force required to operate the board game levers. The client has very poor muscle tone,
and therefore is unable to provide the necessary force needed to play this game. While designing an
assistive device to be used for this purpose, several ideas came to mind in order to minimize the forces
necessary. Some of these designs may be viewed in Team 8’s Alternative Designs report. The alternative
chosen as the optimal design utilizes a motor with a lever arm attached to push down on the Hippo
lever. This lever will be controlled by the client via a touch-sensitive button interface. By utilizing a
motorized control system with push button, the amount of force required from the client to operate the
game will be greatly reduced.
The two other alternative designs considered during the design process included mounting a
linear actuator to the lever in order to provide the necessary force or to use a pulley system in order to
minimize the forces needed. The pulley system was almost immediately rejected because the
complexity of the design would have been significantly increased, and there was no guarantee that the
required forces needed after implementation would be achievable by the client. The linear actuator
design on the other hand was strongly consider because the forces it exerted would be directed in a
linear fashion when making contact with device. However, upon researching some linear actuators on
the market, they were found to be rather slow operating, and would not provide the responsiveness
needed to implement this assistive device. The final design settled on incorporates the best components
both of these alternative designs by providing a quick response action, while at the same time
completely minimizing all of the necessary force.
Initially, the assistive device was going to be removable in order to be adaptable with other
Hungry, Hungry Hippos board games; however, after some reconsideration, it has been decided that the
assistive device will only function with the board game provided by the client. The reason for this change
is due to the fact that there are a number of different models of Hungry, Hungry Hippos games
available, and each has a slightly different setup. This makes the adaptability of the proposed device
rather limited, if not impossible, and it would be in the client’s best interests to create a high quality
device aimed specifically at operating with the client’s game.
The major components that will make up the adapted Hungry, Hungry Hippos game will be the
board game itself which has already been provided, the user push button, an electric DC motor, the
lever arm which will be directly attached to the motor, and the housing for the device. The device will
also be battery operated and is intended to be mountable onto one of the four stations located on the
client’s board game. The way in which the assistive device will be implemented is pressing down on the
push button will complete the circuit between the motor and the power source. This will allow the
battery to power the motor which will in turn rotate the lever arm and make contact with the board
game levers. A simplified version of the component setup can be seen in Figure 1 below.
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Figure 1: Component Setup for H.H.H. Assistive Device
1.2 Subunits
There will be three major subunits that will construct the overall assistive device. The subunits
include the motor with swing arm, the push button control, and the housing which will encompass the
device and attach to the board game. The motor and swing arm will be used to provide the necessary
force to the board games levers, the push button will be used to control the device, and the housing will
encase the assistive device.
1.2.1 Motor & Swing Arm
The motor is the main component which will provide the necessary force to the board games
levers. It will be a store-bought, small electric DC motor which will provide the necessary torque needed
to interact with the levers. A swing arm will be attached to the motors spindle and will provide the
actual interaction between the board game and motor. The swing arm can also be purchased from most
online hobby stores, or, alternatively, can be machined. In Figure 2, a generalized setup of the motor
and swing arm is modeled.
Figure 2: CAD Model of Motor and Swing Arm
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In order to determine the amount of force needed to operate the board games levers, a one
pound weight was allowed to rest on top of the game, and the subsequent result showed that indeed a
one pound force was all that was needed. When choosing a motor to use, this one pound force will
then be the base line, and anything that will provide this torque, or greater, should be sufficient for the
project’s need. A main factor to be considered during motor assembly is the location in which it is
placed, relative to the hippo lever. Depending on the length of the swing arm purchased, the location of
the motor will change in order to accommodate for the increased or decreased length. It is important to
adjust for this change because the swing arm needs to come in direct contact with the board games
levers, and not doing so would either result in the motors getting caught on the game and locking up, or
the games levers not properly functioning. Another important factor which will be considered when
choosing a motor is its size. The motor should not be too large because, depending upon its positioning,
the client’s view while playing the game could be obstructed. Also the larger the motor is, the larger the
housing will need to be, and a very large assistive device is not practical, in this case.
When it comes time for assembly of the assistive device, the motor and swing arm will first be
attached and hooked up to a battery in order to determine that everything is secure and functioning as
intended. The motor assembly will then be manually held in place next to the board game levers in
order to confirm, before final assembly, that the motor generates the required forces needed for
operation. The current motor which is being considered is the “Small Johnson Motor” as seen in Figure
3. It has a splined shaft to allow mounting, the stall torque is within our needs at 78.8 oz-in, and the size
factor is small which will be ideal for mounting in the housing unit.
Figure 3: “Small Johnson” Electric Motor
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1.2.2 Push Button
The push button is what the client will use to activate or turn off the motor, thus assisting in his
interaction with the board game. There are a number of various push buttons available on the market
which range in price and size. The most important aspect is that the one chosen for use must be
sensitive so that very little force is needed to depress it, and that it has a relatively large surface area so
that the client can easily navigate to it. A picture of some current buttons available for purchase can be
seen in Figure 4.
Figure 4: Jelly Bean Style Push Buttons
The operation of the button will be an on-off mechanism, so that when the button is pushed
and held down, the motor will operate the board game until the button is released. The switch will
operate by completing the circuit between the battery power supply and the motor. The original idea
was to have the motor activate only for a limited time when the push button is pressed allowing for
greater interaction experience with the board game. Upon revision, however, this has changed since the
client, in all likelihood, will not be able to rapidly press down upon the button to keep up with the other
players, without becoming fatigued. The final design will continuously run the electric motor, while the
user his holding down the button, which will allow for much easier operation by the user.
Upon integrating the push button with the other components, it will remain movable so that the
client can position it as he chooses. The button will be hard wired into the assistive devices casing, and
will contain enough slack in the cord so that proper placement can be achieved. In order to test the push
button it will be attached to a battery, and the motor. The button will then be pressed and the motor
will be observed for proper polarity. A mock up CAD image of the push button can be seen in Figure 5
below.
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Figure 5: CAD Model of Push Button
1.2.3 Housing Unit
The housing unit’s main purpose will be to hold all of the components together, and to allow the
device to fit onto the board game with proper positioning. The housing will be fabricated out of sheet
metal, and will resemble the model shown in Figure 6. The final housing unit will be as small and
compact as the purchased components allow, in order to minimize any visual interference between the
client and the game. There will be an area designated for the motor and swing arm, as well as a cavity
which will contain the batteries. The top of the casing will also have a notch cut out so that the swing
arm can rotate freely and come into contact with the board games levers. In to attach the device onto
the Hungry, Hungry Hippos game there will be two prongs that protrude out that will be placed
underneath the board game.
Figure 6: CAD Model of Housing Unit
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The housing will also include an extension arm which will interface with the board game’s other
lever mechanism to operate the marble release. It will have a large surface area so that the client can
easily make contact and push down to release the marbles while playing. Figure 7 below shows the
location of this marble release button.
Figure 7: Marble Release Button Location
Their will not be much testing of the housing unit other than ensuring a proper fit between it
and the board game. In order to harness the motor assembly to the housing unit, motor mounts will be
purchased and fastened onto the area in which the motor will rest. Example mounting units currently
available for purchase can be seen in Figure 8.
Figure 8: Mounting Unit for Motor
Finally, Figure 9 provides a CAD illustration of all the components integrated together
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Figure 9: CAD Model of Component Setup
2. Adapted Sled
2.1 Introduction
The adapted snow sled for Joey is a sled that will allow his mother or father to pull him around
on the snow, while keeping him safe and secure. The main concern is to make sure that the sled keeps
Joey safe and secure while being pulled around. This will be accomplished by bolting a plastic support
seat to the sled. There will be a piece of quarter-inch plywood between the seat and the sled to provide
a flat base on which the sled will be mounted. Important features of the seat include the following: an
adductor between the legs in order to prevent Joey from sliding out and a full harness across his
shoulders and chest to keep him secure in the seat. This design was chosen as the optimal design
because it is the easiest and most cost-effective method to implement that meets all the specifications.
The sled is provided by the client, which reduces the time and effort of either purchasing a sled or
making one from raw materials. The most expensive item is the seat; however, the model chosen for
this design is one of the most affordable seats available, which satisfies all of the project specifications
without any modifications.
2.2 Subunits
2.2.1 Sled & Support Seat
The sled to be used is made of plastic and is strong enough to support the weight of the seat
and the client. The seat to be used was originally designed for use as a swing. It is made of plastic and is
tall enough to support Joey’s head without additional modification. It has an adductor between the
legs, as well as a full harness built into the seat to secure his shoulders and waist. The harness is secured
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with a plastic clip above the adductor. Figures 10 and 11 depict the sled and seat to be used in the
design. If desired, some cushioning may be added to the seat for the client’s comfort.
Figure 10: Sled to be used in design
Figure 11: Full support swing seat
2.2.2 Bolts and Nuts
Two stainless steel bolts and two stainless steel nuts will be used to secure the seat to the sled.
Stainless steel is being used in order to prevent corrosion, because the sled will be used outside on
snow.
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2.2.3 Quarter-inch plywood
The quarter inch plywood was chosen for a base because it is cheap and lightweight. Its main
function will be to provide a flat surface between the seat and sled in order to facilitate a better
attachment of the seat to the sled.
2.2.4 Sled Testing
Once assembled, the sled’s stability needs to be tested in order to make sure that the seat’s
connection to the sled is secure. Initial CAD simulation testing showed no sign of failure or deformation
in the plastic sled from the bolts, but this will have to be confirmed on the final product, itself, after
thorough testing.
Figures 12, 13, and 14 below are CAD drawings of the seat-sled combination. The pictured seat
is a simplified depiction of the actual seat, but the drawings give a good idea of how the final product
will look.
Figure 12: Rear view of adapted sled
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Figure 13: Lateral view of adapted sled
Figure 14: Front view of adapted sled
3. Device Control Panel
3.1 Introduction
The portable control panel to be constructed for the client’s use will remotely control his
Emerson CD player, portable Coby DVD player, and turtle light. The panel will switch these devices on
and off, and it will also change the colors of the light emanating from the turtle. Jelly-bean style buttons
will be built into the panel to control these functions in the devices. In the case of the CD player and
turtle light, these switches will be wired into a Basic Stamp 2 microcontroller, which will output to two
different transmitters (one for the turtle light and one for the CD player) that will give out an RF signal to
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the receiving end, which will be comprised of two receivers and a microcontroller connected to
corresponding switches on the light and CD player. In the case of the DVD player, the switches will be
wired directly into the circuitry of the remote supplied by the manufacturer in order to produce the IR
signal to be emitted for Play and Stop. An IR-RF extender from Next Gen will be incorporated to utilize
the low frequency RF waves emitted by the remote and transmit them to a second transceiver, which
will convert the RF signal back to the original IR signal and transmit it via an IR emitter to the IR receiver
on the DVD player. Figure 15 below is a diagram which describes, in a general way, how all these
components will fit together.
Figure 15: Overall panel design
3.2 Subunits
3.2.1 Turtle Light and CD Player Control
3.2.1a Microcontroller Input from Control Panel Switches
A picture of the touch sensitive buttons that will be used in the client’s control panel may be
seen in Figure 4 in the discussion about the adapted Hippo game. The buttons for the panel, however,
will be smaller. These are buttons that were especially requested by the client’s mother, as Joey is
familiar with these switches and they require very little force to be generated by the client for their use.
Switches
MC 1 Light
Transmitter
Pulse
Transceiver 1 IR Remote
Control Panel
Light
Receiver
CD Player
Transmitter CD Player
Receiver
Receiver Hub
MC 2
RF Signal
CD
player
Light
High Pulse
DVD
Player
Low Frequency RF
Transceiver2
& Processor IR Emitter
IR Signal
Battery Battery
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Also, the relatively large surface area and bright colors further contribute to their ease of use. The
control panel will have two of these switches designated for control of the CD player (Play and Stop),
and three switches designated for control of the light (On/Green Light, Off, Blue Light, Auburn Light).
Each of the switches, when pressed, will complete the circuit between the 9VDC battery supply,
required by the Basic Stamp microcontroller, and a digital I/O pin on the microcontroller. Five pins on
the microcontroller (P0-P4), one for each switch, will be designated as input pins. When a button is
pressed for a particular function (i.e., play CD player), its corresponding pin will receive a high input to
be read in by the microcontroller. The microcontroller will then be programmed to distinguish between
pins and to send out data, via one of two transmitters, to one of two receivers and a receiving
microcontroller to carry out the task desired by the user (i.e., playing the CD player). Each transmitter
and its corresponding receiver will be set at a particular frequency, which will be determined by the
particular transmitter used. This will be discussed in more detail in upcoming sections. Figure 16
depicts the pin diagram for the Basic Stamp 2 which will be used in this design project. It also depicts the
setup for the CD player’s and light’s panel switches and their corresponding transmitters. P0 and P1
control Play and Stop, respectively, for the CD player. P2-P5 control On/Green Light, Off, Blue Light,
Auburn Light, respectively.
Testing of this subunit would involve ensuring that the jelly-bean switches close the circuit
between the Basic Stamp 2 pins and the power source so that the initiation of the signaling may take
place. An oscilloscope probe could be used for this purpose.
Figure 16: Switch, Basic Stamp 2 and transmitter configuration
3.2.1b CD Player and Turtle Light Transmitters
It was decided to present the optimal design for this small project, using two separate
transmitters and receivers for the CD player and turtle light to simplify the microcontroller’s signal
processing and differentiation. If it is necessary, for financial purposes, to use only one receiver and
transmitter for both devices, then this is possible to do, but microcontroller code will have to be written
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to allow the microcontroller to be able to differentiate between signals for the light and the CD player
and then send them to the correct device to be executed.
As depicted in Figure 16, each of the transmitters for the light and CD player will have an input
connected to one of the digital outputs (P12 & P13) on the Basic Stamp 2. From P12 and P13, the
transmitters will receive pulsed data, which will be transmitted at the outputs as radio waves (RF). Each
transmitter will transmit data at a particular frequency and its corresponding receiver will receive data
at that same frequency. The frequency between the two halves will be set by configuring the oscillating
crystals built into the receivers. By having separate frequencies for each transmitter/receiver pair,
interference will be greatly reduced and signals for different devices won’t get crossed. Example Code 1
and 2 below, written in Visual Basic, describe how these pulsed signals will be programmed into the
microcontroller to be transmitted by the transmitters . The turtle light’s transmitter will receive four
different types of commands: On/Green Light, Off, Blue Light, Auburn Light. Similarly, the CD player’s
transmitter will receive two commands: Play, Stop. It will be the microcontroller’s job on the receiving
end to distinguish between these commands, based on pulse pattern and interval.
‘This code controls Play and Stop on the CD player
‘{$STAMP BS2}
‘{$PBASIC}
IF IN0=1 THEN ‘If the Play button is pushed perform the subsequent commands
PULSOUT 13, 500 ‘Output high pulse at P13 with a duration of 500 ms
PAUSE 20 ’Leave 20 ms between each pulse
ELSE IF IN1 =1 THEN ‘If the Stop button is pushed perform the subsequent commands
PULSOUT 13, 300 ‘Output high pulse at P13 with a duration of 300 ms
PAUSE 15 ’Leave 15 ms between each pulse
ENDIF
Example Code 1: Basic Stamp 2 code for CD player’s Play and Stop signals to be transmitted by RF
‘This code controls On/Green Light, and Off functions on the turtle light. The turtle is wired by the manufacturer so
that one button controls On/Off/Green Light; therefore, this project will utilize this wiring.
‘{$STAMP BS2}
‘{$PBASIC}
IF IN2=1 THEN ‘If the On/Green button is pushed perform the subsequent commands
PULSOUT 12, 500 ‘Output high pulse at P12 with a duration of 500 ms.
PAUSE 20 ’Leave 20 ms between each pulse.
ELSE IF IN3 =1 THEN ‘If the Stop button is pushed perform the subsequent commands
PULSOUT 12, 400 ‘Output high pulse at P12 with a duration of 400 ms.
PAUSE 15 ‘Leave 20 ms between each pulse
ENDIF
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‘This code controls the Blue Light and Auburn Light functions of the panel.
‘Note the different pulse frequencies used, which will allow the receiving microcontroller to distinguish between
commands for the turtle light.
‘{$STAMP BS2}
‘{$PBASIC}
IF IN4=1 THEN ‘If the Blue Light button is pushed perform the subsequent commands
PULSOUT 12, 300 ‘Output high pulse at P12 with a duration of 300ms.
PAUSE 10 ’Leave 10 ms between each pulse.
ELSE IF IN5=1 THEN ‘If the Auburn Light button is pushed perform the subsequent
‘commands
PULSOUT 12, 100 ‘Output high pulse at P12 with a duration of 100ms.
PAUSE 5 ’Leave 5 ms between each pulse.
ENDIF
Example Code 2: Basic Stamp 2 code for turtle light’s On/Green Light, Blue Light, Auburn Light signals
to be transmitted by RF
Testing of this subunit would involve debugging the Basic Stamp 2 code and ensuring that the
pulses get passed along to the appropriate receivers.
3.2.1c CD Player and Turtle Light Receiver and Microcontroller
On the receiving end, two separate receivers will be accepting signals for the turtle light and the
CD player. One microcontroller will accept these signals and pass them to the appropriate device. Figure
17 below depicts the receiver setup for this design. P0 and P1 accept the RF signals coming in from the
transmitters. P15 and P14 connect to transistors in the CD player that must be soldered in place of the
DPDT switches for Play and Stop provided by the manufacturer, which will be desoldered. These
transistors will thereby control the Play and Stop functions of the CD player. DPDT switches require
physically closing the switch, while a transistor electrically closes it when it receives a high voltage on
one pair of its terminals. It then causes the current to flow through its other pair of terminals by
manipulating resistances to the current, thereby completing the circuit between the input signal and the
CD player’s mechanism for turning the CD. P9-P11 also connect to transistors in the turtle light, which,
like the CD player, utilizes physical push buttons to complete the circuit. The transistor at P9 will control
On/Off/Green Light, the one at P10 and P11 will control Blue Light and Auburn Light functions. Each
transistor in the turtle light will connect between the input signal and the color LEDs inside the turtle
shell, which receive their power and ground from the three AAA batteries inside the battery casing.
Color LEDs work by changing the direction of the flow of current through its anode and cathodes.
Depending on the direction of the flow, a particular color will glow. The manufacturer has the push
button switches wired so that, depending on which button is pushed, the current will flow in different
directions through different wires, causing a particular color to shine. The transistors will simply replace
the push buttons and utilize the rest of the circuit to create the same outcome. There is also a physical
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switch on the bottom of the turtle light that must be flipped to On in order for any of the functions to
work. It is assumed for this project that the client will manually turn on this switch.
It’s important to emphasize that all that is required to make these devices function is that a
signal be provided at the appropriate switch to indicate to the device that it should perform that
function. The team is simply replacing the mechanical switch with an electrical one that is then ready to
accept an incoming signal from the microcontroller. Example Code 3 & 4 indicate the type of Visual Basic
code necessary to allow the Basic Stamp 2 to differentiate between different commands for both
devices. The rest of the circuitry within both devices will remain intact to execute the incoming
commands (i.e., the LEDs in the turtle light and the circuitry in the CD player to turn the CD).
Figure 17: Receivers and Basic Stamp 2 configuration
‘This code controls the Play and Stop functions on the CD player
‘{$STAMP BS2}
‘{$PBASIC}
PulseDuration VAR BYTE ‘Create variable to store duration of incoming pulses
DO
PULSIN 0, 1, PulseDuration ‘Reads in pulse at P0 for CD player and measures the duration
‘of each high (1) pulse, storing it in PulseDuration
IF PulseDuration = 500 THEN ‘If the signal has a pulse duration of 500ms at this pin, then this is a
High 15 ‘Play signal and the microcontroller outputs a high voltage at
‘P15 to close the circuit and play the CD.
ELSE IF PulseDuration = 300 THEN ‘If the signal has a pulse duration of 300ms at this pin, then this is a
High 14 ‘Stop signal and the microcontroller outputs a high voltage at
‘P15 to close the circuit and play the CD.
ENDIF
LOOP
Example Code 3: Play and Stop for CD Player
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‘This code controls On/Green Light, Off, Blue Light, Auburn Light functions on the turtle light
‘{$STAMP BS2}
‘{$PBASIC}
PulseDuration2 VAR BYTE ‘Create variable to store duration of incoming pulses
DO
PULSIN 1, 1, PulseDuration2 ‘Reads in pulse at P1 for light and measures the duration
‘of each high (1) pulse, storing it in PulseDuration2
IF PulseDuration2 = 300 THEN ‘If the signal has a pulse duration of 300 ms at this pin, then this is a
High 11 ‘blue light signal and the microcontroller outputs a high voltage at
‘P11 to close the circuit and turn the blue light on
ELSE IF PulseDuration2 = 100 THEN ‘Auburn light signal; following two IF statements are similar to those
High 10 ‘above
ELSE IF PulseDuration2 = 500 THEN ‘On/Green Light signal; this 500 ms duration is at a different pin then
High 9 ‘the 500 ms coming in from the CD player, so the microcontroller
shouldn’t get ‘“confused”
ELSE IF PulseDuration2 = 400 THEN ‘Off signal
High 9
ENDIF
LOOP
Example Code 4: On/Green Light, Off, Blue Light, Auburn Light for turtle light
Testing of this subunit would involve ensuring that the pulse signals that are received by the
receivers carry through all the way to the devices so that the appropriate functions are performed when
the corresponding switches on the panel are pressed. Testing of this subunit would also involve
debugging the Basic Stamp 2 code to ensure that the microcontroller can appropriately measure the
duration of the pulses being passed to it, so that it can send the correct signal to the desired device.
3.2.2 DVD Player Control
3.2.2a Switch Connections and Transceiver setup for DVD player
The DVD player will be controlled separately from the microcontroller and transmitters used to
control the CD player and turtle light. This separate arrangement was decided on mostly because the
DVD player has its own built-in control system, which accepts infrared signals and will not accept the RF
signals given off by the transmitter. In order to overcome this challenge, the circuitry from the remote
control that the manufacturer provides will be utilized within the client’s control panel to transmit the IR
signals associated with the Play and Stop functions. The Play and Stop pushbuttons from the panel will
be wired into the remote’s circuitry, so that pushing the buttons on the panel will trigger a response
from the remote embedded within the panel by completing the circuit between the power supply and
the rest of the remote’s circuitry. Then, Next Gen’s Wireless RF Remote Extender will also be utilized
within the panel to convert the IR signal given off by the remote into an equivalent RF signal. This device
may be purchase for between $49-$60.
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According to the patent for this extender (US Patent # 6,400,480 for a Battery Module
Transceiver for Extending the Range of an Infrared Remote Controller, filed April 4, 2002), the device
consists of a battery-sized transceiver and power supply. Figure 18 below is a diagram taken from the
patent which describes the design. As stated in the patent, “It is noted that a radio frequency (RF) signal
4 of about 30-50KC accompanying the emission of the IR signal 3 will be radiated all around the IR
remote controller 1 which is representative of the IR signal.”1 (The numbers 1, 3, and 4 refer to the
corresponding numbers in Figure 18.) Therefore, unlike most other IR-RF extenders, the IR signal is not
“converted” in the conventional sense, rather it utilizes the remote’s equivalent RF pulses and uses its
transceiver to detect these pulses, modulate and amplify them, and finally transmit them as an RF
signal. The transceiver and its rechargeable battery supply are placed in a casing and then inserted
inside the IR remote’s battery cartridge in place of one of its AA or AAA batteries. The transceiver’s
battery powers both the remote and the transceiver.
In the team’s design, however, the extender will not be placed inside the battery cartridge of
the remote, since the remote’s casing will most likely be removed to be used within the panel. To limit
the amount of batteries to be charged, the remote’s circuitry, and hopefully the extender, will all be
powered by the panel’s one rechargeable battery supply. The team doesn’t anticipate a problem in the
transceiver’s ability to detect the RF pulses from the remote by placing and sodering the extender near
rather than in the remote, since the module acts as any other RF receiver, and the inventor’s placement
of the extender seems to be more for the purposes of convenience and aesthetics rather than
functionality. In place of the remote’s own buttons acting as switches for the remote, the control panel’s
buttons will be wired to the remote’s circuitry to control the switch functionality.
Testing for this subunit will involve the following two components: 1) Testing the connections
between the control panel’s buttons and the remote’s circuitry to ensure that the appropriate infrared
signal is given off for the Play and Stop functions 2)Testing of the extender to ensure that the infrared
signal is being converted into an equivalent RF signal and transmitted to the receiving end to control the
DVD player. Testing will be accomplished through trial and error. Oscilloscopes and LabView’s National
Instruments signal measuring capabilities may be useful in tracking current flow and voltage, especially
when testing the switches.
1 Free Patents Online: All the Inventions of Mankind at http://www.freepatentsonline.com/y2002/0105698.html
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Figure 18: Overall view of the extender’s design, as taken from its patent
3.2.2b DVD Player Receiver Component
Next Gen’s extender is supplied with a second transceiver which accepts the RF signal given off
by the first transceiver in the panel and then converts it back to the original IR signal. This IR signal is
emitted via an IR emitter which is supplied by the manufacturer and placed in front of the IR receiver on
the DVD player. Therefore, both the second transceiver and the emitter would have to be placed in
close proximity to the DVD player. Figure 19 below describes this receiver setup, as presented in the
patent. Testing for this component would be done in conjunction with the previous subunit discussed,
as described in the preceding paragraphs.
Figure 19: Setup of second transceiver, as taken from its patent
3.2.3 Power Source
As power sources, two +9V batteries will be required, one for the receiver hub to power the
receivers and the microcontroller, and one for the control panel, itself, to power the microcontroller,
transmitters, IR remote, and extender. The Next Gen receiver unit for the DVD player comes with an
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adapter that’s powered with a wall socket. Therefore, this is not of concern in the design. The “trick” in
regard to this component of the device will be to power all the components in each unit with one
rechargeable battery, including that component which traditionally has its own source of power, the IR
remote. The question that remains is whether powering all of these devices on one battery will be too
much of a drain on the battery life. If this is the case, then a higher voltage battery power source may
be necessary, in which case transducers will be required to drop the voltage to the appropriate value
required, or a separate battery source may be necessary to power the remote and extender.
These questions will have to be settled through testing, and, if changes need to be made to the
power design, batteries can be purchased easily enough. Testing would include checking that each
device is fully functional under one power source in each unit and then it would be important to keep
track of the battery’s life under this stress. A very short batter life would not be acceptable.
3.2.4 Housing
The final component involves housing for all the electrical components in the panel, which will
probably be custom-made. The casing will be plastic and will have slots custom made to fit the jelly-
bean buttons to control the devices. Figure 20 below is an illustration of how the casing may look once it
is complete. Exact dimensions of the casing have yet to be decided on because the team feels it
necessary to have a better handle on the exact size of the electrical components to be purchased before
deciding on a size for the panel, although 7in x 7in x 5in may be a reasonable estimate or goal.
Eventually a detailed AutoCad drawing of the specifics of the casing will be constructed. Pictures will be
included on the casing to help facilitate Joey’s understanding of how to use the panel.
Figure 20: Control panel housing
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4. Realistic Constraints
4.1 Adapted Hungry, Hungry Hippos Game
In terms of cost and manufacturability, designing an adapted game should be quite inexpensive
and simple, requiring very few or no unique pieces to be specifically manufactured for the device. A
motor, a jelly-bean switch, and material for the lever and the housing are the only materials to be
purchase. All of these parts may be found for relatively reasonable costs.
Other constraints to be considered are the sustainability of the device, if under frequent use,
the environment the game will be played in, and the convenience of the device, or lack thereof. In terms
of sustainability, like any electrical/mechanical tool, the more stress it is under, the more likely it is to
fail; therefore, this needs to be taken into consideration when designing
4.2 Adapted Snow Sled
Large amounts of manufacturing will be limited, once again, for this project, as the client has a
sled that she uses for Joey, which may be adapted for this project, and a pre-made support seat will be
purchased and mounted on the sled.
Safety concerns are foremost for this project. As mentioned earlier, Joey’s entire trunk and head
must be supported and he must be kept from slipping out of the support chair.
In terms of sustainability, the sled and seat adaptation must be weather resistant, as it will be
used in cold temperatures in the snow, and it has to be relatively “rugged” to sustain jerks, or bumps, as
it slides across the snow.
4.3 Switch Panel
The switch panel will be the most expensive of all three devices, with the jelly-bean buttons
probably exciting the most cost. The only sustainability issue foreseen for the switch panel would be
problems caused by dropping the panel or shaking it around too much, as it is meant to be a portable
device.
In terms of manufacturability, the only tailor-made component of the device will be the housing
for the panel’s circuitry. The most difficult thing about that will probably be mounting the buttons, as
the cuts made for these switches will have to be very precise, so that they fit very snugly.
5. Safety Issues
5.1 Adapted Hungry, Hungry Hippos Game
When constructing this assistive device the two major safety components that need to be taken
into account are the mechanical movement of the motor and swing arm, and any sharp edges formed
from the sheet metal which will construct the housing unit. Because the swing arm will be operating
partially outside the housing unit and will be making contact with the board game there is the possibility
of injuring or jamming a finger if its movement is obstructed. In order to account for this possibility, a
safety guard will be implemented to help prevent any ill-advised interactions between the device and
the client. Also to address any sharp edges that may be present due to the sheet metal, the device will
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try and limit the amount of sharp corners. The metal will also be filed down smooth so that no ruts are
present, and if necessary the edges can be covered in a protective padding.
5.2 Adapted Sled
The adapted sled poses the greatest safety issue out of the three assistive devices for the client.
The main concern is that the client be safely seated in a comfortable position, as well as be secured so
that he cannot fall out. If the seat were to come undone and fall off the sled it could cause injury.
Similarly, the seat must do a good job holding the client secure so that any jostling movements will not
affect the client, and so that the client cannot accidently become unrestrained and fall out. The chair
used will be one which the client is already familiar with, and which has been proven to provide the
proper support and security which he requires, as he uses a similar seat on his swing set.
5.3 Control Panel
When constructing the control panel the only real safety concern is the inner workings of the
panel itself. There will be many electrical components placed within close proximity of each other,
housed in a relatively small enclosure. Because of this situation there will be a concern for short
circuiting between components and flammability. Also because the device will be in contact with the
client the need to keep temperatures generated inside to a minimum is essential. In order to address
any heating issues, upon examination, if it is determined that excessive heating is occurring, ventilation
slots can be put in place. In order to prevent any short circuiting between electrical elements, efforts will
be put into place to insulate any exposed wiring, and the circuit layout will be carefully considered to
maximize the available enclosure space.
6. Impact of Engineering Solutions
All three of these devices to be designed for the client will have a societal impact on Joey. Their
purpose is to increase his independence and to enable greater interaction with his environment. People
who suffer from disabilities, such as cerebral palsy, are limited in their abilities to “do for themselves.”
Therefore, even small things, such as these three projects, that make some kind of independence a
possibility, can go a long way in adding to a person’s feeling of self-worth and value, as a human being.
As a result, these endeavors are well worth the effort for that reason alone.
On a large scale, beyond even this client’s personal needs, these projects are examples of how
engineering can be applied to very simple, everyday life and tasks. Often times engineering is associated
with very complex, intricate developments and designs, but it is just as useful, effective, and, perhaps,
even more appreciable among the ordinary things of life, as well. Therefore, on a global level, these
small projects carried out for Joey Toce are a good reminder that engineering’s purpose is to improve
life on every level, even the simplest, through the marriage of science and creativity.
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7. Life-Long Learning
During the course of designing these three projects for the client, new skills have been learned
and old skills have been refined. Traits such as time management, responsibility, teamwork, and
leadership have also played a large role during the evolution of the designs. Each one of these traits is
vital to working in a real world environment, and, by practicing such traits, Team 8 has gained a valuable
foothold for future endeavors.
Some of the new information that was learned came directly from the client and his mother.
Because Joey has cerebral palsy, it was necessary to learn more about his condition and assess what
special needs would have to be put in place. The team learned that the muscle tone in his arms and legs
fluctuates, and he can go from being very strong and stiff to limp. Also due to global apraxia, he has
motor planning difficulties and must undergo numerous repetitions in order to learn a new movement.
While searching for current devices on the market which performed the same functions as our designs,
it was found that there is a large market designated specifically for people with disabilities. Although this
market exists there is still a need for further developments and this need helped the team appreciate
and think in different ways about how to solve the problems presented for our designs.
In addition to the information learned about the client, traits such as leadership, new skills and
techniques have been learned and applied. Some of the new skills learned are computer modeling using
Autodesk Inventor, electrical circuit design and adaptation, and a general overview of mechanics. While
creating each design, the overall mechanical nature needed to be considered, and in doing so the design
was refined so that the problem was overcome as efficiently as possible. This analysis and refinement of
the mechanical design is an important skill to learn because it builds upon what was learned in the
classroom, and then applies that information in a practical way in order to solve the problem presented.
Another major skill acquired was computer modeling with CAD. What this allowed the team to do was
render and design each device and determine the way in which it would perform before any actual
implementation needed to be done. Autodesk Inventor is a very good skill set to learn because it can be
applied later on in life for many applications whether it be in a future job designing components,
performing rapid prototyping, or just designing a pet project.
Overall, the skill sets that were learned and applied during the design process for each project
provide valuable experience which can be built upon in future careers. By learning more about the
clients’ condition a greater understanding for his disability can be appreciated, and his needs can be met
appropriately. Also skills such as CAD and electrical circuit design helped to apply the material learned in
the classroom to everyday life, and provide valuable experience for future endeavors.
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