EZ-Park System & Application

CpE 322

Joe Truncale, Clifford Hults, Lucas Bilar, Muhammad Abdul Rahman, Brian Tagalog

3/4/2011

An EZ-Park system using Bluetooth & GPS technology in conjunction with an iPhone

application to alleviate parking issues from major cities.

Contents

Mobile Application Development – J. Truncale..........................................................1

Solar Charging Technology – L. Bilar..........................................................................3

Global Positioning System (GPS) – M. Abdul Rahman................................................6

Bluetooth...................................................................................................................7

Design Constraints – C. Hults.....................................................................................9

Mobile Application Development – J. Truncale

As cited in the previous assignment, one of the downfalls of the software

related report is that there was no experience programming for the iPhone using Xcode.

Since then, I have taken the initiative to join the iOS Apple Developer Program and

downloaded the latest 4.2.1 SDK and Xcode 3.2.4.

In an effort to better understand the coding behind iOS, I have also begun reading

“Sams Teach Yourself iPhone Application Development in 24 Hours 2nd Edition”, which

is filled with helpful information, as well as step by step tutorials to learn the process by

which one can code for iOS. During this ongoing learning process, I have learned some

off the basics of Objective-C, including syntax and how to code header files (.h) and

method (.m) files.

Another important lesson came from learning how to use the interface builder

included in Xcode, which save countless hours creating buttons, text fields, and other

GUI objects. The interface builder not only allows one to create these images, but also to

link them in a simple way to the underlying code. Using a simple drag and drop

technique, you can click the object on the interface and connect it to the method you

coded.11 Using these tutorials, I have already gotten closer to understand the iOS

Development process and have even coded two of my own apps that now reside on my

iPhone 4.

As noted from the Trade Journal, Dr. Dobb’s, “Mastering Objective-C is the key

to unlocking the iPhone’s potential”. The memory of an iPhone can be considered as a

pile of bytes stacked one upon the other. When assigning a variable a value, the system

reserves a certain amount of bytes at a memory address. For example, declaring “int x =

45” could reserve four bytes at address 928 and that will be the data’s current location.

Pointers are also another valuable piece of information needed for coding. Using the

syntax int*, it symbolizes that that value is a pointer and doesn’t contain the value. It

“points” to another memory address where a value is stored. When one wants to indicate

that a pointer is not referencing an important value, one can set the value to “nil”, the

equivalent to. By declaring pointers as “nil”, you can make sure you are only dealing

with relevant pointers and not just everyone of them.2

Another great piece of information I discovered on the Dr. Dobb’s Trade Journal

was a piece on displaying tabular data on iPhones. The class that manages the iOS

device screen is called UIView. This class is responsible for showing the content and

capturing user input. The subclasses known as UITableView and UITableViewCell

inheret the same abilities as UIView but they don’t store data. The purpose of these

subclasses is only to display data and interact with the “app’s data repository”.

UITableView is in charge of table layout and functionality. It allows cells to display and

1 Ray, John. Sams Teach Yourself IPhone Application Development in 24 Hours. Indianapolis, IN: Sams Pub., 2011. Print.2 Fairbairn, Christopher K., and Collin Ruffenach. "Pointers in Objective-C." Dr. Dobb's: The World of Software Development. 16 June 2010. Web. 3 Mar. 2011.

organize the data and enables UIScrollView to allow the table to be scrolled. Cells are

relatively advanced. They have the ability to display text, images and other controls.3

Strengths:

The strengths of this portion of the report is that this group member took the initiative to

learn about how the iOS development process worked. By enrolling in the developer

program and following tutorials, the individual now has a greater grasp of how to actually

code.

Weaknesses:

The weaknesses of this portion of the report are that the group member was unable to find

exact information that was relative to his portion of the project. Instead he was forced to

share new information learned about the basics of Objective-C. Though this is still

helpful, it is relatively vague. when compared to the overall project

Solar Charging Technology – L. Bilar

Solar power has recently become a major topic in science and engineering

because it is a clean and efficient way of powering many of the things we use today.

Solar energy can be used to power many electronic devices using the sun, thus it does not

have to rely on any electrical wires and connections. Our group plans to use solar

technology in order to charge the portable EZ-park device we are designing. A solar

charger is necessary because the device will have to stay on without being connected to

an electrical power source. If at any point it were to die, a driver would be at risk of

getting a ticket, even though he might have already paid to park there.

3 Thompson, Tom. "Displaying Tabular Data on IPhones." Dr. Dobb's: The World of Software Development. 26 Feb. 2011. Web. 3 Mar. 2011.

The principle part of a solar charger is the photovoltaic process, which uses cells

to convert the sun’s energy directly into electricity. Solar panels are made up of multiple

cells which are connected together in a module and covered with thin layers of

semiconducting material such as silicon. When the silicon is exposed to sunlight,

electrical charges are generated within the cells. These charges can be conducted away

by metal contacts, creating a direct current.

Photovoltaic cells are one technology which utilizes the above mentioned process.

The most widely produces cells are made out of silicon.4 These are made through a

crystal growing process, which can be either single-crystal or multi-crystalline. The latter

are less expensive to produce, but they have a relatively lower energy conversion

efficiency. Cells can also be made out of other materials including gallium arsenide or

iridium selenide. These can be more efficient than silicon ones, but are also more

expensive to produce. If our team plans to use these cells, we need to look into the prices

and efficiencies of each of these cells and decide which one fits our design.

One new technology which our group can possibly use in the design of our device

is the recently popular organic photovoltaic cell.5 It is made up of carbon-based

polymers, which allows it to be used in high-speed, low-temperature roll-to-roll

manufacturing. Since capital costs are low, these cells can be produced at high rates and

at large volume. Although no life cycle analysis has been made, it is known that rooftop

stability of these modules is over a year. Moreover, these cells are predicted to cost less

than $1 per Watt. Several other useful properties of these cells include its light weight,

flexibility, low cost, and a high power to weight ratio. These properties make the organic

4 Gutowski, Casey: Photovoltaic Technologies; Photonics Spectra5 Gaudiana, Rusell: Organic Photovoltaics; Photonics Spectra

photovoltaic cell particularly useful for portable applications including battery chargers.

They can be adhered to the outside face of many things such as a briefcase, or they can be

incorporated into a device’s housing. In our case, they can be adhered to the back of the

EZ-park device. I believe this technology would fit our design very well and definitely

should not be overlooked.

Another interesting new product which our team can look at for inspiration is the

new solar charging cell phone. LG’s new, eco-friendly phone is equipped with a solar

panel battery cover.6 The user can point the phone’s solar panel at natural light and the

panel will convert solar energy into electricity without needing to be plugged in. The

phone’s solar power system is embedded onto the battery cover. Our team can

implement a similar design where a solar panel is attached to the cover of the EZ-park

device. We first must look further into the way the solar panel attaches to the phone

battery and charges it.

Strengths:

My resources are pretty in-depth and can be helpful for our design. They discuss many

basic principles of solar power, which can help our group get started on our design. They

also discuss some more advanced principles and explain new technologies which are

being developed, that perhaps our group can employ in our design.

Weaknesses:

6 Rose, Melinda: Highlights From Mobile World Congress 2009; Photonics Spectra

I think I could have found some more sources which show how solar panels are

connected to a battery to allow charging.

Global Positioning System (GPS) – M. Abdul Rahman

GPS is a satellite navigation system which is funded and controlled by the U.S.

Department of Defense (DOD). Basically, GPS provides specially coded satellite signals

that can be processed in a GPS receiver enabling the receiver to compute position,

velocity and time.

GPS has three segments which are space segment, control segment and user

segment. The space segment consists of 24 satellites that orbit the earth in 12 hours.

These satellites send radio signals from space to GPS receivers. The transmission of those

signals is very efficient because the signals are one way signal. The control segment

consists of a system tracking locations located around the world in order to monitor the

satellites orbit and maneuver them. It receives signals from the satellites and incorporated

them into orbital models for each satellite. Then, the precise orbital data and the atomic

clock are calculated before sending them to the satellites. The user segment consists of

GPS receivers that convert the GPS signals into position, velocity and time. GPS

receivers can receive signals from different satellites.

The position of a GPS receiver is determined from multiple pseudo-range

measurement at a single measurement epoch. In the other word, the position of a GPS

receiver is determined by the intersection of signals from several visible satellites. The

time difference of the time signal is sent and the time signal is calculated is used to

calculate the distant between the receiver and the satellite. A minimum of four satellites

is required to provide 3D dimensional position. Five or more satellites can provide

position, time and redundancy while extra satellites can provide extra position fix

certainty and can allow detection of out-of-tolerance signals under certain circumstances.

However, the information provided also depends on the technology used for the receiver.

The velocity is calculated from change in position over time, the satellites Doppler

frequencies or both. On the other hand, time at the receiver is determined by the signal

send by the satellites. There are a total of four atomic clocks in each satellite and these

clocks are monitored by the ground segment in order to maintain the time to within one

millisecond of GPS time.

The satellites are operating 24 hours a day for every year. As a result, GPS can be

used anytime whether in the night or in the day in the whole year. In addition to the 24

operating satellites, there are other 3 standby satellites in case one of the satellites is

malfunction. Besides, as the satellites are sending one-way signal to the receiver without

receiving signal from the receiver, there will be no delay in sending the signals. Hence,

when applying GPS to our device, the parking location can be identified in no time delay.

This makes GPS a very reliable positioning system. 78

Bluetooth

As other mobile devices, our EZ-park device is also come with Bluetooth

technology. Basically, it is a short range wireless technology that is intended to replace

the wire technology while maintaining high levels of security. The technology enables

the device to communicate directly with user mobile phone application to conduct

7 Dana, Peter H. "The Global Positioning System." University of Colorado Boulder. 1999. Web. 03 Mar. 2011. <http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html>8 GPS. The National Coordination Office for Space-Based Positioning, Navigation, and Timing. Web. 24

Feb. 2011. <http://www.gps.gov/>.

payment. The fact that our device uses Bluetooth technology makes it very convenient as

most mobile phones nowadays are included with Bluetooth technology or it can be said

that Bluetooth technology is well accepted in many devices around the world nowadays.

It works by establishing wireless connection between Bluetooth enabled devices

in a short range ad hoc network known as piconet. Piconet is established automatically

meaning that the connection is available whenever and wherever it is convenient to the

user. A Bluetooth enabled device can connect up to 7 other Bluetooth enabled devices in

the same piconet and it can also belong to several other piconets as well. The range

between Bluetooth enabled devices is varied from 1 meter to 100 meters depending on

the class of radio implementation used in the devices.

Bluetooth is using radio technology that operates in the unlicensed industrial,

scientific and medical (ISM) band at 2.4 to 2.485 GHZ. As a matter of fact, 2.4 GHz ISM

band is available and unlicensed in most countries making the Bluetooth technology

widely used for most devices around the world. It works in the band by using spread

spectrum frequency hopping called adaptive frequency hopping (AFH) in order to reduce

interference between wireless devices sharing the 2.4 GHz ISM band. It detects other

devices in the band and avoids the frequencies they are using. This creates a more

efficient transmission and a greater performance even when other technologies are being

used along with Bluetooth technology. Besides, Bluetooth has the ability to

simultaneously handle data and voice transmission.

New Bluetooth technology version 4.0 provides low power consumption by

allowing the radio to be powered down when inactive. The radio is turn on only when

needed for data transfer giving a power optimization benefit. This is proved by the ability

of the technology to run for years on standard coin-cell batteries. Besides, this increases

the security of the radios.9

Strengths:

My resources are about the concepts of GPS and Bluetooth. Basically, the concept of

these two technologies is mainly about signal. Hence, by learning how the signal works

can help to create a device that includes GPS and Bluetooth technology.

Weaknesses:

If I can find more resources about the technical details of GPS receiver it will be great. I

also try to find a solution for GPS receiver to work at parking with close environment but

I still cannot find it.

Opportunities:

I also need to find the common details calculation of the position done by the GPS

receiver so that I do not end up making my own calculation that might go wrong.

Design Constraints – C. Hults

Economic:

The interesting part of this project is how we will find a way to subsidize the cost of parts

and manufacturing. We want as much of the public to use the device as we can. The best

way we could accomplish this is if we take a similar approach as the EZ-Pass system.

They have you pay a small security deposit for the device that sits up in your window or

on your license plate but it saves you some money when paying for tolls along the

parkway and/or turnpike. If we use a security deposit system, the consumer will treat the

9 About the Technology." The Official Bluetooth® Technology Web Site. Web. 03 Mar. 2011. <http://www.bluetooth.com/Pages/About-the-Technology.aspx>

unit with care, driving our manufacturing costs down, and subsidizing the cost of the unit

itself. We can possibly integrate this into a standard GPS device. If we do this, we can

work with an already established manufacturing plant to produce our equipment,

allowing us to drop our costs significantly, as well as keep pollution down, and

unnecessary use of valuable lot space, from multiple industrial manufacturing sites.

Environmental:

We must make sure that the device is the least possible detriment to the environment at

any point in its life. We can use recyclable materials where applicable. Also, when a

device may be broken, or malfunction, the customer would send back the device to us,

this keeps the units out of the trash, lowering the waste production. If we can't get the

devices to work when we receive then, we can then scrap them for parts to use for other

devices that are fixable. Any other parts we cannot use, we can dispose of properly, or

recycle them if applicable.

Health and Safety:

Make sure that the radio bands on the device are not interfering with heart monitors,

WMTS and other medical frequencies as well as any commercial wireless frequencies. It

must be kept to a size that does not restrict, or hinder, the driver in any way. If we

manufacture our device to have a body style similar to a GPS device (Garmin, TomTom,

etc.) found in most cars today, it will be out of the way to allow site of the road. Another

route is to modify a GPS device with a custom OS. This gives our device the ability to

give GPS directions, as well as, find a parking spot and allow you to pay for it too. This

will lower the amount of things hanging in front of the driver, and lowering their risk of

accidents. Heat is also a major concern of electronics. We must keep the surface

temperature of the device at a comfortable temperature so not to burn the user, damage

the internal electronics, or melt the outside shell. Batteries end up being one of the first

issues to come up. If they overheat, they can rupture, ignite or explode hen exposed to

high temperature. This would obviously be a very big problem in terms of safety of use

for the consumer.

Sustainability:

A major concern definitely belongs to the lifespan of each device. We want to be able to

have the longest lifespan possible for the device since we would be the ones taking the hit

of the cost if the device happens to malfunction or become disabled in some way shape or

form. Battery life is one of the biggest concerns as they are usually the first part to go.

We also want to check to see if our battery life is optimal. Most common rechargeable

batteries have a lifetime of 1000 recharge cycles and a lifetime of about 2-3 years, before

their internal resistance becomes too great for the battery to hold a charge. More

specifically would probably end up using a Lithium Ion battery, the same battery used in

laptops, cellphones, etc. These batteries are very common, come in various shapes and

sizes, and would meet our specific needs for this project.

Ethical Responsibilities:

Privacy is a huge concern while you're using a GPS system. Customers get nervous that

their locations and/or transactions are going to be saved and tracked. This is where a

privacy policy comes into play and must be utilized to protect the company from lawsuits

and to assure the customer that their information will not be shared or compiled in such a

way to track their location. It is very important to the customer and to us that their safety

of the utmost importance. The only exception to this would be if the police were to ask

for a location of a suspect, our system could give them the whereabouts of the car they

were, or are, in if they were to use this product, or as a simple lo-jack system if the car is

lost or stolen.

Group Contributions: Mohammed Abdul Rahman – GPS and BluetoothLucas Bilar – Solar ChargingCliff Hults – Design ConstraintsJoe Truncale – ApplicationBrian Tagalog – Will be sending separate work