Requirements and Functional SpecificationsUniversity of Portland, Shiley School of Engineering

EE/CS 480A Senior Design Project Preparation

Magnetic Manipulator

Team 125Marley Rutkowski (Fall Team Lead), John Olennikov,

Chad Perkins, Benjamin YounceFaculty Advisor: Dr. Robert Albright Industrial Advisor: Andy McConnell

Client: Dr. Mark Utlaut

October 4th, 2013

Table of Contents

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page

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Development Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Milestones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Preliminary Budget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Appendix A: Milestones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Appendix B: Budget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

FiguresFigure 1. System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 2. Electromagnet Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Stand Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4. Use Case 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5. Use Case 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6. Use Case 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 7. User Interface Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Introduction

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Team 125 will be designing a magnetic levitation device which will manipulate a small object controlling its movement in a small area of vertical 1D space without physical interaction. The team hopes to eventually extend this idea to achieve controlled levitation in 2D space.

Levitation will be achieved by switching on and off the electromagnets above the levitating object to maintain its desired position. The system will monitor levitation position of the object and if it is below the desired position the electromagnet is switched on, and if it is switched off again when the object is at the desired position. Stable levitation is achieved by repeating this process very rapidly. The user will be able to adjust the vertical position of the levitating object by decreasing the percentage of the time that the powering electromagnet remains on to allow the object to drop, and increasing this time to lift the object. Team 125 hopes to expand the device to achieve horizontal movement by using a second electromagnet positioned adjacent to the original to pull the object to the side, eventually achieving stable levitation under the second electromagnet.

Many examples of systems that have achieved levitation using a single electromagnet, with a Hall Sensor at the tip of the electromagnet and positioned above a metallic object exist. Team 125’s system will build upon this idea with the added adaptability of position control. Accurate manipulation of the object will require experimentation once the team’s physical system is set up. However, by choosing an Arduino as the center of the team’s logical system, there will be a lot of opportunity in fine-tuning the system to work as desired. In the team’s finished project, the user will be able to control the levitation movement using a computer connected by serial to the microcontroller, or to allow the object to levitate in a pre-programmed movement pattern.

This concept could eventually be expanded to utilize additional adjacent electromagnets to achieve levitation in a larger area, and possibly in 3D space. The device will serve as a conceptual demonstration for a technology that can be applied to numerous fields, potentially including manufacturing or even eventually in patient medical surgery.

Requirements

Team 125’s magnetic levitation system will require at least 9 major components: an Arduino, computer, electromagnet*, Hall Sensor*, levitating object, power source, transistor*, voltage regulator*, and an enable switch. The primary goal of Team 125 will be to achieve controlled levitation under a single electromagnet in one dimension. Once this has been achieved, the team hopes to achieve controlled levitation in two dimensions by adding a second electromagnet. The inclusion of a second electromagnet will also require an additional set of each of the control system components marked by an ‘ * ’, in order to control the second electromagnet. Figure 1 is a block diagram of all of the system components and how they interact, descriptions are below.

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Figure 1. System Block Diagram

1-Arduino: The Arduino microcontroller is the central brains of Team 125’s system. It is responsible for interpreting commands from and providing information to the user, tracking the levitation of the object through the Hall Sensor, and controlling the power given to the electromagnet via the transistor.

● User input data will be received by the Arduino as bytes sent over a serial wire by the computer. When commands are available in its buffer the Arduino will have to read in and interpret them in order to determine how the state of the system will be affected.

● System state data will be encoded by the Arduino and sent over serial to the computer in order to provide the user with information to improve system control.

● Hall sensor data will be read in by the Arduino on an analog pin and interpreted in order to track the position of the levitating object at any given time.

● Interpreted position data will be interpreted by the Arduino in order to determine the how to control the electromagnet given the current position of the levitating object and the desired position.

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2-Computer: The computer will serve as the user interface for the magnetic manipulation system. The user will be able to input commands into a custom GUI which will be encoded and sent over serial to the Arduino to be executed. The GUI app may also have to buffer commands to make sure that they are not sent too fast for the Arduino to read because it has a serial queue of limited size. The GUI should also decode and display pertinent data about the system state, received from the Arduino over serial.

3-Electromagnet(s): The electromagnet creates the magnetic field that interacts with the levitating object keeping it in place. It is activated and deactivated by the transistor that controls the power provided to it. The electromagnet must be powerful enough to maintain levitation of our object within a minimum maximum range of at least 2 inches. 4-Hall Sensor(s): Hall Sensor data will be used to gather information on the position of the levitating object. A hall sensor varies its output voltage in response to the magnetic field; the Arduino will monitor this data on one of its analog input pins. From this information the Arduino will be able to extrapolate the position of the levitating object at the given time. The Hall Sensors must be strong enough to accurately sense the magnetic flux of a ferromagnetic with an induced charge strong within a 2-inch range. 5-Levitating Object: The objective of Team 125 is to levitate a small object, weighing 5-10 grams. The team will design the Magnetic Manipulator to levitate a 1/2 x 1/8 inch disc neodymium magnet. Once the team has accomplished this, they will attempt to apply the system to levitating light ferromagnetic objects, such as a hollow steel ball of approximately ¼ inch diameter. 6-Power Source: The power source provides the energy necessary to activate the electromagnets. Team 125 will use a power source which meets the power requirements of the electromagnets. Based on current research, the Magnetic Manipulator system will require a 12V DC power supply, which can supply 4-5 Watts at minimum. 7-Transistor(s): A transistor will be necessary to switch the power to the electromagnet on and off. The transistor will take power, provided by the power source, through the power regulator. The transistor will then supply power to the electromagnet when activated, and supply no power when not activated. A digital control signal from the Arduino will be used to activate and deactivate the transistor.

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8-Voltage Regulator(s): The voltage regulator maintains a constant voltage supply to the system, independent of the power supply and the current load. It takes power in from the power source and provides power to the transistor circuit that is responsible for controlling power supplied to the electromagnet. It may be necessary to use an adjustable power regulator so that the output voltage may be adjusted by the Arduino via an analog signal. The technical specifications of the team’s voltage regulator will depend on the power supply and electromagnets that Team 125 chooses to use in the system. 9-Enable Switch: Team 125 will include a physical two-state switch that can be used to enable and disable the levitation system. The switch will be connected to one of the Arduino’s digital input ports. When disabled, the electromagnets will have no power supplied to them. When enabled, the system will work as specified. General Specifications

System Layout:Figure 2 depicts how the team plans to lay out the electromagnets and Hall Effect

sensors if the system is extended to execute controlled levitation in two dimensions. For the team’s primary one-dimension goal, one of the electromagnet and Hall Sensor systems will be utilized.

Figure 2. Electromagnet Layout

Stand: Team 125 will build a stand to suspend the electromagnets above the area of manipulation. This stand must be sturdy, but it must also allow for an unobstructed view of our levitation system at work. The team must also be able to place the system electronics somewhere that the magnetic fields generated by the electromagnets will not interfere with them. In order to achieve these goals, the team will use a hangman-style stand that will allow for an unobstructed view at three out of four angles. With this design, the electronics will be placed on the base of the stand of the Magnetic Manipulator, opposite of the levitation area. Plexiglas is a promising material for the construction of the stand. Making the stand out of Plexiglas would

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also allow for the system to have a relatively unobstructed view from the back. Figure 3 gives an idea of how the system will look.

System Dimensions:

● The minimum distance of magnetic manipulation control that the system should achieve is 2 inches, so the electromagnets will have to be mounted high enough to allow for improvement from this goal with some leeway. By building the mounting structure so that the electromagnets are about a foot above the base of the mount, there will be enough room for improvement on the team’s 2-inch goal.

● The electromagnets will have to be far enough away from the stand so that the movement of the levitating object will not be obstructed. The first electromagnet will be placed 2 inches from the vertical of the stand to allow for enough space. This will put the entire top structure, or overhang, of the stand at approximately 5 inches.

Figure 3. Stand Design

Use Cases

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1. An instructor in a physics class is teaching the concept of the Hall Effect. The instructor turns on the device and reads the value for the current magnetic field produced by the device. The instructor then places a metal object in the device’s magnetic field and waits for the object to stabilize. The instructor then reads the distance of the object from the magnets, and the pulse-with-modulation value. The instructor can press the “up” or “down” arrows on an interface to adjust the distance between the object and the magnets. This will demonstrate to the class how the pulse frequency of the electromagnet changes to maintain steady levitation at the new location.

2. A train-like vehicle sits on its tracks. The train conductor activates the magnets inside the tracks; the train separates, and levitates above the tracks. The conductor presses a throttle forward and the magnets surrounding the vehicle change the intensity of their magnetic fields to propel the train forward. When the conductor pulls back on the throttle, the magnets surrounding the vehicle change their intensity to slow the vehicle to a stop. The conductor de-activates the magnets and the vehicle descends onto the tracks, preventing further movement of the vehicle.

3. A small child has swallowed a small metal toy and is at risk of dying. The doctor doesn’t want to perform an operation that will cause excessive harm to the child, now or during recovery. The doctor places the child on a platform that contained in the magnetic field. Due to the Hall Effect, the doctor will use Hall sensors to figure out where the object is located in the body. The doctor then guides the metal object out of the child’s body.

User Interface

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The layout of the user interface is displayed in Figure 7.

Figure 7. User Interface Layout

Pulse Frequency will be the raw data from the Arduino chip that will display the frequency values of voltage applied to the electromagnets.

Magnetic Field will be the “calculated” value of the approximate magnetic field produced by the magnets.

Object Distance will be the “calculated” distance from the object to the magnets.

The UP and DOWN buttons will provide the user with the ability to raise or lower the object.

Development Process The development process for the Magnetic Levitation project will take place in three phases:● The first phase will consist of documentation and planning. All responsibilities for all

parts within this phase will be split evenly amongst the team members. Planning will take place at team meetings and group emails. The duty of writing documents will be divided evenly throughout the team by the team leader.

● The second phase will consist of construction and Arduino coding. The housing and support structure for the machine will be tasked to the School’s technicians. Electrical wiring and construction will be primarily the responsibility of Ben and Chad. The coding and user interface will be primarily the responsibility of Marley and John. All team members will have minimal responsibility in all areas during the second phase, most prominently in the form of feedback and input during team meetings.

● The third and final phase will consist of debugging, final documentation, presentation, and possibly the addition of multidimensional motion control. Again in this phase all responsibilities will be split evenly amongst the team members by the team leader. The exception to this will be the possible implementation of multidimensional motion control.

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If time allows, additional motion control will be added to the functions of the device. Responsibilities to add these functions will fall primarily on Marley and John for coding and Ben and Chad for electrical construction and wiring.

Milestones

See Appendix A - Milestones (p16)

Preliminary Budget

See Appendix B - Budget (p18)

Technologies

Team 125 will use two or more electromagnets positioned above a metallic object to lift and move the object. Hall Sensors or other tracking technologies are utilized to monitor the position of the object being manipulated. An Arduino or other comparable programmable microcontroller is the brains of the Magnetic Manipulator. Additionally, Team 125 will use DC voltage sources, as well as drivers for the electromagnets of the levitation system.

Facilities

The magnetic manipulation project will require open space in a lab in order to construct it. Construction of the Magnetic Manipulator will require a soldering iron, drill, saw, safety equipment, pliers, wire cutters and superglue. The group will work off site for design and research of the model. Special software is required to program the Arduino, which is provided on the internet for no charge. The group will also need small items such as screws, nuts and bolts to secure the device to a platform.

Risks

● The parts that Team 125 orders do not get to the school in time. ○ To avoid this, multiple suppliers will be assigned for each part. Team 125 will

order parts on October 25th, well before Winter Break, to ensure that enough time is available if something goes wrong in obtaining them.

● If the solenoids or power supply are not powerful enough, the levitation will not work. ○ One way to avoid this is to order solenoids and power supplies that have the

capacity to provide well beyond the magnetic field and voltage that is required, but within the budget. The parts will be ordered with enough time in between planning and building, so if something goes wrong there will be time to order new parts.

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● Levitating an object and then moving it in two dimensions is much harder than anticipated and the group cannot complete the model in the allotted time.

○ In this case, Team 125 will change the focus of the project to levitating an object with stability in a single location.

● The Arduino software or Hall Sensor cannot perform the way they are required for magnetic levitation, such as insufficient processing speed, or programming is much more complicated than anticipated.

○ If this is the case, different chips and sensors must be ordered. The group will have backup suppliers and products researched for this reason. Extra construction time has been allotted for programming complications.

● The configuration of a DC power supply and an AC Arduino supplement does not work. ○ There are multiple ways to implement magnetic levitation. If the group has

trouble with a certain power source configuration, a backup will have been arranged.

● The schematics are incorrect (incorrect values for resistors, wrong wiring diagrams, incorrect input/output voltage, incorrect Arduino programming or inability to correctly interpret Hall Sensor).

○ If any of these are causing problems, 125 will stop all construction of the model and re-do the schematics instead of attempting to fix them on the fly.

● A part breaks or malfunctions. ○ Multiple numbers of each part will be purchased so the group has backups and

does not have to wait for more parts, which could potentially sink at least a week’s worth of work.

● There is insufficient lab space to work on the Magnetic Manipulator. ○ In the case of insufficient lab space at a meeting time, the group will reconvene

at a different time in order to meet set deadlines.

● Sickness of a team member. ○ If a team member is sick or unavailable and cannot complete their part of the

project, it will potentially slow down the entire team, make others work harder and longer, and therefore the project could take longer. The other team members must step in and complete their assigned work in order to prevent missing any deadlines or milestones.

● The prototype breaks. ○ If the prototype breaks (for example, if it falls on the floor or somebody sits on it)

the whole project will have to be redone. To avoid losing time from this, the group will obtain extra parts when ordering them and take care when transporting the Mag-Lev device. The device is projected to be completed in plenty of time before

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the presentation in case it is damaged and more work has to be done on it. Once constructed, the prototype will have a demonstration on video in the case that it is destroyed in transport to the presentation.

Constraints ● Technical – The construction of the Magnetic Manipulator device will have a limited

effect on industry. If the machine becomes common use in, for example, the medical industry or in education, this will motivate more IC manufacturers to design chips specifically for levitation uses.

● Economic – The Magnetic Manipulator will have a positive economic impact if the technology from the machine is used in other machines in industry.

● Environmental – There is very little environmental impact from the use or construction of this device. The Magnetic Manipulator has no moving parts so it will be durable. There is some environmental impact from the material sources used in manufacturing the machine. The device itself has no harmful emissions and a majority of the materials used to construct it are recyclable.

● Social – If magnetic levitation technology is applied in a user friendly device that improves the quality of life for the user, this technology will become very popular and change the way humans interact.

● Political – If the Magnetic Manipulator were used in the medical field, then the radiation effects may become a charged political issue. If the device were used in surgery, there will be some concern about the radiation in close proximity to vital organs which may in turn charge political concerns. However, the amount of radiation produced by the machine is very small.

● Professional – Improvements in motion control using magnetic fields has great potential for future invention and further improvement on electromagnetic technology.

● Ethical – The effects of radiation on humans is an ethical concern. The magnitude of concern would depend mostly on which industries were adopting the technology and for what use. If the Magnetic Manipulator were used, for example, in manufacturing to levitate parts down an assembly line to reduce friction and wear, there may be a small concern of the effects of radiation emitted from the device on workers’ bodies. This concern will be greater in the case where the same technology were used to manipulate medical instruments during surgery.

● Legal – If magnetic motion control is used in high-risk applications, there could be legal consequences if the machine fails. The use of this technology in high-risk applications should be included in the insurance policy of a company using magnetic manipulation.

● Health and Safety – In general, the risk to health and safety for this technology is minimal. If used in medical equipment, then malfunction or possibly radiation could cause an injury. However, both cases will be uncommon.

● Security – Does not apply. The use of the magnetic manipulation system must be localized within the boundary of the machine and therefore does not pose any security risk of any kind.

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● Manufacturability – This machine and technology is easily manufactured. All of the parts used for this particular machine are common electrical and electronic devices. More design-specific devices for other machines using this technology may have an initially long lead time. However, once established, all manufacturability using this technology should be straightforward.

● Sustainability – Materials used in this device are recyclable. Some construction materials, like the structural components, can be sourced from recycled material.

● Standards – IEEE standards for electromagnetic motion control are already established. More standards will be added to include Hall Sensor and Arduino technologies as this method becomes more widely used.

● Codes – There will be a small amount of electrical noise created by a device using this technology that would have to conform to FCC regulations.

Conclusion

Team 125 will strive to develop a system that will achieve stable magnetic manipulation controllable in at least the vertical plane. The team has chosen a flexible design, so after achieving this result we hope to have the opportunity to extend our goals into further dimensions. The Magnetic Manipulator’s design will allow the user to have a high level of control, but still have insight on how it is working. In developing Team 125’s system, the team will face lots of trial and error testing in order to develop the code to make the device work properly. Therefore, one of the team’s biggest challenges will be the testing of the Magnetic Manipulator and the potential of accidentally damaging system components. Team 125 will order extra parts so that if components are damaged, progress is not greatly inhibited. Although the team’s ultimate goal of 2D magnetic manipulation is a stretch on the skills of each team member, Team 125 has provided itself with goals of increasing difficulty and achievable milestones that will lead to the ultimate success of the Magnetic Manipulator.

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Bibliography

Arduino. 2013. http://arduino.cc/en/Guide/ArduinoDue (accessed September 5, 2013).

DigiKey. http://www.digikey.com/ (accessed September 7, 2013).

HacknMod. 2013. http://hacknmod.com/hack/how-to-controlled-levitation-using-magnets-microcontrollers/ (accessed September 15, 2013).

Instructables. 2013. http://www.instructables.com/id/Use-Arduino-with-TIP120-transistor-to-control-moto/(accessed September 11, 2013).

SparkFun. https://www.sparkfun.com/products/9312 (accessed September 4, 2013).

YouTube. http://www.youtube.com (accessed September 1, 2013).

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Glossary

Arduino A single-board microcontroller to make using electronics in multidisciplinary projects more accessible.

electromagnet A type of magnet in which the magnetic field is produced by electric current, flowing through coils.

enable switch Can be switched on or off to provide high/low logic.

Hall Sensor A transducer that varies its output voltage in response to a magnetic field.

Team 125 A Senior Design Project team consisting of Marley, Chad, Ben and John.

magnetic field A region around a magnetic material or a moving electric charge within which the force of magnetism acts.

magnetic levitation A method by which an object is suspended with no support other than magnetic fields.

Magnetic Manipulator A device constructed by Team 125 that sustains controlled levitation of a small object.

power source A device that supplies electric power to an electrical load.

transistor a semiconductor device used to amplify and switch electronic signals and electrical power.

solenoid A coil wound into a tightly packed helix used to create magnetic fields.

transistor A semiconductor device with three connections, capable of amplification in addition to rectification.

voltage regulator A device that automatically maintains a constant voltage level.

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Appendix AMilestones (Fall Semester 2013 and Spring Semester 2014)Note: Major Milestone deadlines and descriptions are indicated in bold.

Due Date: Description: Type:

Fri 13 Sep Complete Initial Draft of All Sections of the Functional Specifications

Minor

Fri 20 Sep Complete Functional Specifications, first complete draft (ver. 0.9) Minor

Fri 27 Sep Complete Functional Specifications, advisor-approved draft (ver. 0.95)Present September Program Review

Minor

Minor

Fri 04 Oct Complete Functional Specifications, final draft (ver. 1.0) Major

Fri 11 Oct Create Parts List, to include pricing and sources. Minor

Fall Break

Fri 25 Oct Present October Program ReviewCreate initial budgetDetermine lead times for parts and create an ordering schedule accordingly.

MinorMinorMinor

Fri 01 Nov Complete Design Document, first complete draft (ver. 0.9) Minor

Fri 08 Nov Complete Design Document, advisor-approved draft (ver. 0.95)Complete Final Budget Draft

MinorMinor

Fri 15 Nov Complete Design Document, final draft (ver. 1.0)Complete Final Budget

MajorMajor

Fri 22 Nov Create initial plan for prototype build. Minor

28-29 Nov Thanksgiving Break

Fri 29 Nov Present November Program Review Minor

Fri 6 Dec Finalize prototype plansDetermine lead time for any technician help.All parts purchased or ordered

MinorMinorMajor

13 Dec-10 Jan Christmas Vacation

Fri 17 Jan Begin programming for Arduino Minor

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Fri 24 Jan Present January Program ReviewBegin prototype build

MinorMajor

Fri 31 Jan Prototype build 50% complete Major

Fri 7 Feb Prototype build 100% completeBegin testing/debugging of prototype

MajorMajor

Fri 14 Feb Present February Program Review Minor

Fri 21 Feb Have at least 1 dimensional movement working Major

Fri 28 Feb Comprehensive Exams Major

Fri 07 Mar Complete Final Report Document initial write Minor

10-14 Mar Spring Break

Fri 21 Mar Complete Final Report, first complete draft (ver. 0.9) Minor

Fri 28 Mar Complete Final Report, advisor-approved draft (ver. 0.95) Minor

Fri 04 Apr Present Final Program Review with DemonstrationComplete Final Report, final draft (ver. 1.0)

MajorMajor

Tue 08 Apr Present Project on Founder’s Day Major

Thu 17 Apr Present “Post Mortem” Review of Project Minor

Appendix BBudget

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Part Supplier Estimated Cost Per Unit

Units Needed

Estimated Shipping & Handling

Total Price For Part

Arduino Due Virtuabotix Direct $46.95 1-2 Free $46.95-$93.90

Solenoid Undecided $20.00 4 Varies $100.00

Hall Sensor Undecided $2.00 3 $1.00 $7.00

Transistors Undecided $0.70 5 Less than $1.00

Under $4.00

Breadboard Undecided Under $10.00

1 $2-$3 Under $13.00

Levitation Object Undecided $5.00 1 Varies Under $5.00

Diode 1N4004 Undecided $0.20 5 Varies $1.00

1K Resistor Undecided $0.10 5 Varies $0.50

1uF Ceramic Capacitor Undecided $0.10 5 Varies $0.50

Power Supply Undecided $10-$50 1 Varies $10.00-$50.00

Voltage Regulator Undecided $5-$10 2 Varies $10.00-$20.00

On/Off Switch Ebay $5.35 1 Varies $5.35

Total Cost 34-35 Varies $203.30-$300.25