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1 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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Mar 17, 2019

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Page 1: 1. Adapted Hungry, Hungry Hippos Game · Adapted Hungry, Hungry Hippos Game 1.1 Introduction When creating the adapted Hungry, Hungry Hippos device the main concern that needs to

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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.