Power Mouse
Final Design Report
Design Team 05
Amy Hicks
Joel Howard
Cody Johnson
Tara McCarthy
Dr. Hamid Bahrami
Dr. Nathan Ida
November 28th, 2011
Table of Contents
List of Figures ................................................................................................ii
List of Tables .................................................................................................iii
Abstract ..........................................................................................................1
1. Problem Statement .....................................................................................1
Need .........................................................................................................1
Objective ..................................................................................................1
Research Survey.......................................................................................1
Marketing Requirement ...........................................................................2
Objective Tree..........................................................................................2
2. Design Requirements Specifications .........................................................3
3. Accepted Technical Design .......................................................................4
Engineering Calculations .........................................................................4
Power Generation...............................................................................4
Solar ...................................................................................................4
Dynamo ..............................................................................................5
Piezoelectric .......................................................................................6
Hardware ..................................................................................................9
Hardware Theory of Operation ..........................................................16
Software ...................................................................................................17
Software Theory of Operation ...........................................................22
Mechanical ...............................................................................................23
4. Parts List ....................................................................................................25
5. Project Schedules .......................................................................................26
6. Design Team Information ..........................................................................32
7. Conclusion and Recommendations ............................................................32
8. References ..................................................................................................33
i
List of Figures
1. Objective Tree............................................................................................2
2. One Press of Dynamo ................................................................................5
3. Period During Consecutive Hand Presses..................................................6
4. One Full Deflection of Piezoelectric Material ...........................................7
5. Estimated Deflection of Mouse Clicks ......................................................8
6. Hardware Level 0 Diagram ........................................................................9
7. Hardware Level 1 Diagram ........................................................................10
8. Hardware Level 2 Diagram .......................................................................12
9. Hardware Schematic ..................................................................................16
10. Software Level 0 Diagram .......................................................................17
11. Software Level 1 Flow Chart ...................................................................18
12. Software Level 2 Flow Chart – Main Loop .............................................19
13. Software Level 2 Flow Chart – Button Interrupt .....................................19
14. Software Level 2 Flow Chart – Timer Interrupt ......................................20
15. Mechanical Mouse Layout – Outside ......................................................23
16. Mechanical Mouse Layout – Inside .........................................................24
ii
List of Tables
1. Design Requirements Specifications .........................................................3
2. Mouse Comparison ....................................................................................4
3. Solar Power Observations ..........................................................................5
4. Mouse Clicks Over Time ...........................................................................8
5. Electrostatic Energy Harvesting ................................................................9
6. Hardware Functional Requirements Level 0 .............................................10
7. Hardware Functional Requirements Level 1 .............................................10
8. Hardware Functional Requirements Level 2 .............................................12
9. Software Functional Requirements Level 0...............................................17
10. Pseudocode ..............................................................................................20
11. Parts List ..................................................................................................25
12. Budget ......................................................................................................26
13. Design Gantt Chart ..................................................................................27
14. Implementation Gantt Chart ....................................................................31
iii
Abstract
[AEH]
Mice are ubiquitous in today’s technology-driven world. However, it is a problem for
those with the wireless variety to constantly change the batteries in it. The solution is to
modify a mouse such that it can power itself through its environment and user interaction.
This will be implemented using a combination of energy harvesting techniques, creating
a mouse that is functional and self-powering.
• Self contained
• Self charging
• Reliable
1. Problem Statement
[JH]
Need
In the United States each year, consumers use more than 3 billion disposable
batteries. These batteries are made with heavy metals such as lead and nickel, making
them difficult to dispose of safely and a danger to the environment[1]. In addition, each
battery produced requires the use of energy, much of which is generated from nonrenewable resources like fossil fuels. With the rise of ‘green’ thinking in the U.S. and the
increased awareness of energy limitations, disposable batteries have emerged as a serious
source of both energy use and pollution[2]. Wireless computer mice are a contributor to
the problem. If a mouse could be designed that required no disposable batteries (and no
outside energy source at all), it could significantly reduce the number of these batteries
used by a family each year - decreasing both energy usage and waste.
Objective
Our design will attempt to remove the external energy source from a wireless
computer mouse, replacing it with an internal device such as a kinetic or thermal
generator. We will design the mouse so that it never requires a disposable battery and
never requires plugging in, instead generating its own power from the user’s movements.
The mouse will need to generate enough power for its own current operation and store
power for quick use later. It will also need to satisfy the other requirements for a usable
wireless mouse: quick response time, accuracy, and sufficient range.
Research Survey
Our research indicates that while the idea has been investigated by various people,
and several concepts exist [3][4]. There are also a number of pending patents, but no
active patents and no product on the market. We also found existing technology that
captures kinetic energy from walking and other everyday movement [5][6], leading us to
believe a mouse would be feasible. We did preliminary research on generating devices
such as Van de Graaff generators [9] and thermoelectric (Seebeck effect) generators
[7][8], and found some existing devices using these concepts to generate energy[10][5].
1
Marketing Requirements
• Self charging
• Low to moderate cost
• Good quality of materials
• Reliable
• Self-contained
• Withstands the heat from sunlight
• Flexible charging methods
• Long usage time from a full charge
• Includes battery meter and low battery alert
• Comfortable use
[TLM]
Objective Tree
[CJJ]
Figure 1: Objective Tree
2
2. Design Requirements Specifications
[TLM]
Table 1: Design Requirements Specifications
Marketing
Requirements
Engineering Requirements
1
1.
Provide at least half of the mouse
power through energy harvesting.
3,4
2.
Should withstand a drop of
approximately 1 foot with no damage.
6
3.
Wireless range should be
approximately 1m.
9
4.
Mouse must be completely contained
in a single housing.
2
5.
Cost of the product including parts and
labor should not exceed $400.
4,7,8
6.
Should have a resolution of at least
200 DPI.
1,7
7.
The system will have a total power
consumption of 50 mW or less.
4,5,7
8.
Includes a right and left mouse button
and scroll wheel.
7,10
9.
Functions in three different modes:
active, light sleep, and deep sleep.
4,6,7,8
10.
USB dongle receives the wireless
signals and translates them to a form
the PC understands.
3
Justification
At least half the power required to operate
the mouse should come from the different
methods of energy harvesting.
Has to be durable enough for normal wear
and tear and light abuse.
For everyday use a range of 1 meter in
any direction away from computer is
sufficient.
To be truly self charging no external
hardware will be needed.
Cost should be low to allow for ease of
marketing in comparison to the normal
and our budget constraints.
The resolution should be comparable to
that of the conventional wireless mice.
A typical off the shelf wireless mouse has
a larger power consumption so for self
charging the total power consumption will
be less.
Most basic mice today include these
features, and would be expected by the
market.
By using different modes, power
consumption would be reduced when the
mouse is not being used.
The PC must know the signals sent by the
mouse.
3. Accepted Technical Design
[AEH, CJJ, JH, TLM]
Engineering Calculations
[TLM]
The accepted mouse design is to create a self powered wireless mouse through the
use of energy harvesting and user movements. Within this design it is required to use an
existing wireless mouse and modify the power input so that it takes in the energy
harvested power from the various methods. Therefore research was needed to find the
various standard mice specifications. Table 2 shows the comparison between the standard
mice specifications. Evaluating these results, the Microsoft 4000 model was chosen to be
the base mouse.
Table 2: Mouse Comparison
Mouse Name
Fujitsu
Notebook
Mouse WI400
Fujitsu Laser
Mouse
WL9000
Microsoft
4000
Microsoft
3000
Battery Type
AAA
AA
AA
AA
AA
AA
Number of Batteries
Power Supply
Mouse
2
2
1
1
2
1
2 - 3.3v
~1.5v
~1.5v
~1.5v
~1.5v
~1.5v
10 months
6 months
10 months
6 months
15mA
15mA
7.5mA
12.5mA
22mA
15mA
Power
Consumption of
Receiver (Max)
50A
35mA
12.2mA
30mA
Frequency
2.4GHz
2.4GHz
2.4GHz
27MHz
27MHz
2.4GHz
Range
10m
10m
5m
1.07m
1.2m
5m
Battery Life
Power
Consumption of
Mouse (Max)
Power Generation
Cherry
Cherry
M-T3000 M-300R
[TLM]
Several forms of energy harvesting have been considered for this application. The
types of harvesting that were considered were: piezoelectric, solar, mini dynamo, and
electrostatic. Some of these methods have been abandoned after some research was done.
This was due to the fact that either it was not applicable in this design or the method did
not generate enough power to be stored to be of use.
Solar
[CJJ]
One form of power harvesting considered was solar. For the observed numbers
seen below in Table 3, a 1.125x1.125 inch solar panel was used, with a 1KΩ resistor
load. From these calculations, it can be concluded that solar panels are a worthwhile way
of energy harvesting, and that there is an advantage to using a lens in the final design to
further improve the panels' efficiency.
4
Table 3: Solar Power Observations
Normal
Room Light
0.145
0.145
0.021025
Volt
mA
mW
With Desk
Light
0.235
0.235
0.055225
Volt
mA
mW
With Desk
Light and
Magnification
0.31
0.31
0.0961
Volt
mA
mW
In Sunlight
2.37
2.37
5.6169
Volt
mA
mW
Dynamo
[CJJ, AEH]
Another power harvesting method implemented in the mouse design is the use of
a small dynamo. This will convert the mechanical power of the user pushing down on a
pedal to electrical power. Essentially, it is the reverse of an electric motor – turning the
shaft of the motor generates electricity. Figure 2 demonstrates the voltage generated from
this procedure. When the pedal is pressed a single time, the voltage is greater at first and
oscillates while deteriorating.
Figure 2: One Press of Dynamo
However, chances are that the user will not press the pedal just ones, but will
pump it a number of times. This effect is measured in Figure 3.
5
Figure 3: Period During Consecutive Hand Presses
To put some numbers to these graphs, with a typical amount of effort on the
user’s part, the dynamo generates about 3.2 volts. Using the maximum effort, this can be
increased to 8.5 volts, with 0.12 amps of current. Additionally, the average frequency of
the hand press can be calculated – simply the inverse of a period in Figure 3. This yields
a frequency of 1/5ms = 200 Hz.
Piezoelectric
[TLM]
The third type of energy harvesting implemented in the design is piezoelectric.
When the piezoelectric strip is flattened, it generates a voltage across itself. This is
because in its normal state, the molecules inside it are arranged in such a way that their
charges cancel out. By flexing this material, they are rearranged enough so that they are
no longer balanced, and a voltage difference is seen. In testing, it was revealed that this
voltage is about 4.5 to 5 volts. The mouse design calls for one of these components under
each of the mouse buttons. This will generate some power each time the user clicks the
mouse, which adds up in the long run.
Figure 4 below shows the voltage of a single full deflection in the piezoelectric
material. As was explained before, when it is pressed down the voltage difference greatly
increases. Once it is released and allowed to return to its normal state, the voltage again
changes – but in the opposite direction.
6
Figure 4: One Full Deflection of Piezoelectric Material
However, a more realistic simulation is the user pressing the button (that then
presses the piezoelectric device) multiple times. Figure 5 below shows this – with a click
being performed about once a second.
7
Figure 5: Estimated Deflection of Mouse Clicks
In order to get a basic estimate of the amount of average user clicks, a light
program called Workrave[12] was installed on one of the lab computers. It then recorded
the clicks over time, which is shown in Table 4.
Table 4: Mouse Clicks Over Time
Mouse Usage (Full Active Mode) (Minutes) 16.283 13.433 41.200 21.800 2.850 6.000 Mouse Clicks 101.567 696.000 710.000 1892.000 955.000 224.000 233.000 Total Number of Clicks 4710.000 Clicks Per Minute of Active Use 46.373 Total Number of Minutes As far as electrostatic energy harvesting is concerned, a limited amount of data
was obtained, as shown in Table 5. Because of the small amount of power that could
actually be obtained from a device small enough to fit inside a mouse, it was deemed
unrealistic to include in the design.
8
Table 5: Electrostatic Energy Harvesting
Device
nPower PEG[5]
EETimesAsia Design[11]
Voltage (V)
5
2.7 - 4.2
Current (mA)
500
?
Power (W)
2.5
0.00005
Size
229x38mm
1x1cm
Similar to electrostatic energy harvesting, the use of temperature has been deemed
unrealistic as well. This is primarily due to the fact that a person’s hand temperature does
not typically vary that much in comparison to room temperature. Therefore the resulted
amount of energy that could be harvested from such a method would be minimal.
Finally vibration and motion energy harvesting was considered. The amount of
actual movement of the mouse was taken into consideration. It was discovered that the
amount the mouse was moved over the course of several hours was minimal.
Additionally, the amount of vibration that could be measured was almost nonexistent. As
a result these two forms of energy harvesting were also eliminated.
Hardware
[CJJ]
Figure 6 demonstrates the functions of the hardware in the mouse at its highest
abstraction. It takes in power from various sources – such as solar and kinetic – and
stores it internally. It also takes input from the user in the form of mouse clicks and the
scroll wheel, and transmits these signals wirelessly to the PC.
Figure 6: Hardware Level 0 Diagram
Table 6 below is the functional requirements of the hardware level 0 diagram.
This table describes the function of each block in the corresponding block diagram.
9
Table 6: Hardware Functional Requirements Level 0
Designer Module Cody Johnson Power Harvesting Inputs Office light, mouse clicks, active user energy Outputs Voltage and current to harge the mouse Functionality To use power harvesting devices such as solar panels, dynamos, and piezoelectric plate to actively and passively charge the mouse battery. The wireless mouse will obtain the power it requires to run through solar and
kinetic energy harvesting and store it internally. The user can then use the mouse as
normal, using movement, buttons, and the scroll wheel to send commands. These
commands are then encoded and sent wirelessly to the receiver in the PC.
Figure 7 below illustrates the level 1 hardware diagram breaking out the major
components of a wireless mouse. The power storage device takes the harvested power
and delivers it the various electrical components.
Figure 7: Hardware Level 1 Diagram
Table 7 below is the functional requirements of the hardware level 1 diagram.
This table describes the functions of each of the blocks in the corresponding block
diagram.
Table 7: Hardware Functional Requirements Level 1
Designer Module Cody Johnson Solar Cell Inputs Office and sun light Outputs DC Voltage Functionality To use solar energy to charge mouse battery. 10
Designer Module Cody Johnson Piezoelectric plates Inputs User kinetic energy in the form of mouse clicks Outputs DC Voltage Functionality To produce a voltage when piezoelectric plate is deflected by a small amount. Designer Module Cody Johnson Dynamo Inputs User kinetic energy in the form of hand presses Outputs AC Voltage Functionality Produces a voltage when hand press generator lever is depressed; the faster the presses are made the higher the voltage generated. Designer Module Cody Johnson Inputs Various voltages from energy harvesting devices Outputs Supply voltage to wireless mouse and power harvesting management PIC Functionality Store the various voltages generated by energy harvesting devices to power mouse PIC Designer Module Cody Johnson Inputs Voltages generated by power harvesting devices Outputs Analog voltage signal Functionality Battery Voltage Detection Produce analog voltage signal to be read by PIC; in order to determine the state of charge of the battery Designer Module Cody Johnson Inputs User button press for state of charge request; analog voltage from Voltage Detection Outputs Send voltages to LEDs to indicate state of charge to user Microprocessor 11
Functionality Determine State of charge, and display charge level to user Designer Module Cody Johnson Inputs Voltage from PIC Outputs Light up LEDs to represent state of charge Functionality Light up LEDs to represent state of charge Display Figure 8 below is the hardware level 2 diagram. This figure describes the overall
flow of how all the hardware components will interact with one another in more detail
than in level 1.
Figure 8: Hardware Level 2 Diagram
Table 8 below is the functional requirements of the hardware level 2 diagram.
This table describes the functions of each of the blocks in the corresponding block
diagram.
Table 8: Hardware Functional Requirements Level 2
Designer Module Cody Johnson Solar Cell ( Solar -­‐ 1) Inputs Office and sun light Outputs 4 Volts with no load Functionality To use solar energy to charge mouse battery. Designer Module Cody Johnson Solar Cell (Voltage Regulation) (MBR1100-­‐ND) 12
Inputs Voltage generated by solar panels Outputs Consistent Voltage flow to the battery Functionality Consistent Voltage flow to the battery Designer Module Cody Johnson Piezoelectric plates (Q220-­‐A4-­‐303YB) Inputs User kinetic energy in the form of mouse clicks Outputs 5-­‐7 volts per mouse click Functionality To produce a voltage when piezoelectric plate is deflected by a small amount. Designer Module Cody Johnson Piezoelectric plates (Voltage Regulation) (LTC3588-­‐1) Inputs Voltage generated by piezoelectric plates Outputs Consistent Voltage flow to the battery Functionality Consistent Voltage flow to the battery Designer Module Cody Johnson Dynamo (Dynamo-­‐1) Inputs User kinetic energy in the form of hand presses Outputs 6-­‐8 volts per press at 0.1 Amps Functionality To produce a voltage when pressed, the faster the presses are made the higher the voltage generated. Designer Module Cody Johnson Dynamo (Voltage Regulation) (LTC3588-­‐1) Inputs Voltage generated by Dynamo Outputs Consistent Voltage flow to the battery Functionality Consistent Voltage flow to the battery Designer Module Cody Johnson Inputs Various voltages from energy harvesting devices Outputs Supply voltage to wireless mouse and power harvesting management PIC Functionality Store the various voltages generated by energy harvesting devices to power mouse PIC Battery (LFP-­‐14430-­‐400) 13
Designer Module Cody Johnson Inputs Various voltages generated by power harvesting devices Outputs Analog signal to the microprocessor Functionality Voltage Detection Input To generate an analog signal that the microprocessor can read to be used to measure the fluctuations in voltage Designer Module Cody Johnson Inputs Battery voltage Outputs Analog signal to the microprocessor Functionality To generate an analog signal that the microprocessor can read to be used to measure the fluctuations in voltage Designer Module Cody Johnson Inputs User button press for state of charge request; analog voltage from Voltage Detection Outputs Send voltages to LEDs to indicate state of charge to user Functionality Determine State of charge, and display charge level to user Designer Module Cody Johnson Inputs Voltage from PIC Outputs Light up LEDs to represent state of charge Functionality Light up LEDs to represent state of charge Voltage Detection Output Microprocessor (PIC24F16KA102-­‐I/SP) Display (516-­‐1293-­‐ND) 14
Designer Module Cody Johnson Inputs Output pin of microprocessor Outputs Input pin of the microprocessor Functionality State of Charge Request Button (P8076SCT-­‐ND) Allow the user to request information from the microprocessor about the state of charge of the battery. Finally, the actual schematic of the mouse power management design is shown in
figure 9. This includes all the components mentioned in the level 2 design, wired together
with the necessary signals.
15
Figure 9: Hardware Schematic
Hardware Theory of Operation
[CJJ]
The power source for the mouse will come from two energy harvesting methods,
solar cells and a mini dynamo. These will, in total, generate enough power to run all of
the other electronics. The electronics being used are the same that one would find in a
standard mouse with the exception of these being low power. Our microprocessor will
16
still take button clicks and scroll wheel movements from the user and transmit this to the
computer. Software
[JH, AEH]
The software portion of this design focuses on the tracking and display of the
charge level on the mouse’s rechargeable battery. The software will be programmed onto
a small PIC microcontroller, which will control 5 LEDs used to display the estimated
charge remaining. Figure 10, below, is the Level 0 block diagram for this software.
Figure 10: Software Level 0 Diagram
Table 9 below is the functional requirements of the software level 0 diagram. This
table describes the functions of each of the blocks in the corresponding block diagram.
Table 9: Software Functional Requirements Level 0
Designer Joel Howard Module Embedded Mouse Software Inputs Power, User Input Outputs Display signals to LEDs Functionality To track the battery level and display it when the user requests or the power is at a critical level. A more detailed view of this software is provided in Figure 11 in the form of a
flow chart. It should be noted that there are two main software modules – the main loop
that runs infinitely and the code that executes during an interrupt that is triggered with a
button press.
17
Figure 11: Software Level 1 Flow Chart
The next diagrams dive even further into the mechanics behind this power
monitoring code, describing in detail how it should work. For this level of detail, three
diagrams are required. Figure 12 is the first of these, showing the main loop of the
embedded program. Next is figure 13, which shows the code executed when the button is
pressed by the user and an interrupt service is run. Finally is figure 14, representing code
which runs on a timer interrupt of every millisecond to monitor battery life.
18
Figure 12: Software Level 2 Flow Chart – Main Loop
Figure 13: Software Level 2 Flow Chart – Button Interrupt
19
Figure 14: Software Level 2 Flow Chart – Timer Interrupt
These diagrams and were then translated into psuedocode – allowing for an easy
transition to real code when it comes time to do the actual programming.
Table 10: Pseudocode
//==============================================================
//Constants:
//sets the amount of time (iterations) for which battery has to be max before we reset the charge count
unsigned char battery_max_threshold;
//sets the minimum voltage expected on a 'full' battery
unsigned int full_voltage;
//==============================================================
20
//==============================================================
//Global variables
//keeps track of the charge used/gained since last reset
unsigned long charge_count;
//keeps track of how long (in milliseconds) the battery has been at max voltage
unsigned int battery_max_count;
//indicates how much longer (in seconds) to display the charge level if user has pressed the display button
unsigned int display_time;
//tracks timer intervals to count up to 1 second
unsigned char timer_counter;
//array of flags indicating whether each LED should be on (for power display)
//LEDs range from 4 (100%) down to 1 (25%) plus 0 (red LED for < 15% charge)
char leds[5];
//==============================================================
//==============================================================
//Interrupt Service Routines (ISRs)
timer ISR{ //every millisecond timer interval
//counter to count up to 1 second
if counter < 1000{
counter++;
}
else{
counter = 0; // reset counter to start counting a new second
if display_time > 0
display_time = display_time - 1; //decrement the remaining seconds to display
the charge
else
led control registers = leds; //send the display values for the LEDs to the output
control registers controlling the physical LEDs
}
start ADC
wait for ADC done
//measure battery voltage
read value from ADC buffer to voltage across battery
if voltage >= full_voltage{
battery_max_count++; //increment the number of consecutive times battery has been
measured full
if battery_max_count > battery_max_threshold{
//assume battery is full and reset the charge count
charge_count = 0;
battery_max_count = 0; //reset the consecutive full count
}
}
else{
battery_max_count = 0; //battery wasn't measured full, reset the consecutive full count
}
//measure battery current
read value from ADC to current in/out of battery
add new charge/time sample to charge_count //integrating by many samples; just averaging over
time and adding
}
button ISR{ //when charge display button goes logic-high
display_time = 3; //display the charge for 3 seconds
}
//==============================================================
21
//==============================================================
//Main
main{
initialize the ADC to read voltage across battery then voltage across current sense resistor
initialize the LEDs
initialize the charge request button
setup button interrupt
initialize timer
setup timer interrupt
while(1){
charge_pct = calculate remaining charge percentage; //calculate what percentage of
charge remains : ((charge_total - charge_used) / charge_total)
//determine which LEDs should be on when displaying charge
leds[4] = (charge_pct > 98);
leds[3] = (charge_pct > 75);
leds[2] = (charge_pct > 50);
leds[1] = (charge_pct > 25);
leds[0] = (charge_pct < 15);
if charge_pct < 15%{
//we're in low battery state, so display this to the user
//set display_time to the appropriate value to display for 3 seconds
display_time = 3;
}
}
}
//==============================================================
Software Theory of Operation
[JH]
The energy-harvesting module will include a small microprocessor to handle
power management. The main responsibility of this unit will be to monitor the charge
remaining in the battery, calculate the average operating time this will provide for the
mouse, and inform the user when appropriate.
The microprocessor will use two methods to monitor the state of charge on the
battery. First, it will periodically measure the voltage across a small resistor in series
with the battery, to monitor current flowing into and out of the battery and manually keep
track of the charge level. Second, it will monitor the voltage across the battery, and if
this voltage stays at a high “full” level for several measurements, will assume the battery
is full and reset the charge count.
The charge count will be used to control five output LEDs – four green (each
representing ~25% of full charge) and one red (to be turned on when charge drops below
15% of full). The software will continually track the appropriate values for these LEDs,
but to save power they will only be turned on when the user presses a charge display
button or when the power is below 15% of full.
22
Mechanical
[CJJ]
Figure 15: Mechanical Mouse Layout - Outside
The above figure shows the outside view of the mouse from all important angles.
It includes the basic components such as the buttons, scroll wheel, and sensor. However,
figure 16 shows a more in-depth look into how the components will fit inside it. The
LEDs along the left side will display the current battery life when the user presses the
button. Additionally, the pedal for using the dynamo is located in the middle of the
mouse, with a switch on the right side to lock it into place to keep it out of the way during
use. Finally, the solar panels are located higher up on the mouse.
23
Figure 16: Mechanical Layout of Mouse - Inside
24
4. Parts List
[CJJ, TLM]
The following table is a list of all the parts needed in the design for a powerharvesting system for a wireless mouse.
Table 11: Parts List
Qty.
4
1
1
4
Refdes
D1,D2,D3,D4
S1
D8
D5,D6,D7,D9
Part Num.
MBR1100
EVQ-11G07K
HLMP-1321
HLMP-1503
1
2
1
1
2
1
2
U4
3
2
1
1
2
2
3
3
3
3
U1,U2,U3
U5,U6
MECHANICAL
R4
R2,R6
R3,R7
C3,C7,C11
C2,C6,C10
C4,C8,C12
C1,C5,C9
3
L1,L2,L3
PIC24F16KA102-I/SP
Solar -1
Dynamo-1
LFP-14430-400
Q220-A4-303YB
N82E16826105450
Y14880R20000B0R
LTC3588EMSE1#PBF
OPA2376AIDGKR
AT4148B
MFR-25FBF-110K
MFR-25FBF-1K00
MFR-25FBF-15K0
T350A105K035AT
T350A475K010AT
T350E106K025AT
T350K476K025AT
TSL0709RA100K1R9-PF
B1
R1,R5
Description
Schottky Diodes
Switch - Pushbutton for charge level request
Red LED - Display battery level
Green LED - Display battery level
PIC - Microcontroller for monitoring state of charge
(sample)
Solar Cell - Power Harvesting method (donated)
Dynamo - Hand Press Generator (donated)
LiFePO4 Single Cell Battery (AA)
Piezoelectric Bending Sensor
Microsoft Wireless Mouse 4000
Current sensing resistor 0.2 OHM
Power conditioning IC (sample)
Current sensing resistor amplifier
Rocker switch - activate hand press generator
110K resistor
1K resistor
15K resistor
1uF Capacitor
4.7 uF Capacitor
10 uF Capacitor
47 uF Capacitor
10uH Inductor
Next is the actual budget for the project. Table 12 shows this, with a total of
$486.84 – under our $600 budget.
25
Table 12: Budget
Qty.
4
1
1
4
Part Num.
MBR1100
EVQ-11G07K
HLMP-1321
HLMP-1503
1
PIC24F16KA102-I/SP
2
1
1
2
1
2
3
2
Solar -1
Dynamo-1
LFP-14430-400
Q220-A4-303YB
N82E16826105450
Y14880R20000B0R
LTC3588EMSE-1#PBF
OPA2376AIDGKR
1
1
2
2
3
3
3
3
AT4148B
MFR-25FBF-110K
MFR-25FBF-1K00
MFR-25FBF-15K0
T350A105K035AT
T350A475K010AT
T350E106K025AT
T350K476K025AT
TSL0709RA-100K1R9PF
3
Description
Schottky Diodes
Switch - Pushbutton for charge level request
Red LED - Display battery level
Green LED - Display battery level
PIC - Microcontroller for monitoring state of
charge (sample)
Solar Cell - Power Harvesting method
(donated)
Dynamo - Hand Press Generator (donated)
LiFePO4 Single Cell Battery (AA)
Piezoelectric Bending Sensor
Microsoft Wireless Mouse 4000
Current sensing resistor 0.2 OHM
Power conditioning IC (sample)
Current sensing resistor amplifier
Rocker switch - activate hand press
generator
110K resistor
1K resistor
15K resistor
1uF Capacitor
4.7 uF Capacitor
10 uF Capacitor
47 uF Capacitor
10uH Inductor
5. Project Schedules
Unit
Cost
$0.42
0.29
0.41
0.41
Total
Cost
$1.68
0.29
0.41
1.64
1.40
197.00
25.99
12.64
1.40
394.00
25.99
25.28
3.00
6.00
0.81
0.13
0.13
0.13
1.06
1.06
1.70
5.11
0.81
0.13
0.25
0.25
3.18
3.18
5.10
15.33
0.64
Total
1.92
$486.84
[TLM]
Table 13 below illustrates the organization of scheduled tasks for the group. The
Gantt Chart shows the required completion date and group resources being supplied for
each task.
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Table 13: Project Schedule Gantt Chart
27
28
29
Table 14 shows the implementation gannt chart. This is the proposed schedule of tasks
for the building and troubleshooting phase of the project.
30
Table 14: Implementation Gantt Chart
31
6. Design Team Information
[AEH]
Amy Hicks, Computer Engineering
Joel Howard, Computer Engineering
Cody Johnson, Electrical Engineering
Tara McCarthy, Electrical Engineering
7. Conclusions and Recommendations
[AEH]
To create a mouse that will be both wireless and self-powered, different aspects
must be taken into account. The ability of the mouse to function as an off-the-shelf mouse
should be the first priority. Next, it should be able to charge itself, through a combination
of user actions and its environment. In order to do this, various types of technology must
be researched so that the best design can be implemented.
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8. References
[AEH]
[1]. http://www.epa.gov/osw/conserve/materials/battery.htm
[2]. http://www.ucsusa.org/publications/greentips/2009/greentips-kick-the.html
[3]. ‘Corky’, concept submitted to Greener Gadgets 2010.
http://cea.mblast.com/ws/wfaward/rsp/vote2.asp?GUID=204654
[4] ‘Dynamo Green Keyboard’, a (fake) device described on I Want One of Those.
http://www.pocket-lint.com/news/13713/dynamo-keyboard-april-fool-iwoot
[5] ‘nPowerPeg’ http://www.npowerpeg.com/
[6] ‘Dickson’s Human Kinetic Energy Electrical Generator’
http://peswiki.com/index.php/Directory:Dickson's_Human_Kinetic_Energy_Electrical_G
enerator
[7] ‘Peltier effect category at World News’ http://wn.com/Peltier_effect
[8] ‘Thermoelectric effects’ http://www.tf.unikiel.de/matwis/amat/elmat_en/kap_2/backbone/r2_3_3.html
[9] ‘How Van de Graaff generators work’
http://science.howstuffworks.com/transport/engines-equipment/vdg.htm
[10] ‘Thermoelectric stove fan’
https://www.gyroscope.com/d.asp?product=VULCANSTOVEFAN’
[11] 'Energy Harvesting Chips'
http://www.eetasia.com/ART_8800378146_765245_NT_1fe14900.HTM
[12] Workrave, http://www.workrave.org/
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