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Hansen-Trost Engineering

Consisting Of: Glenn Trost and Paul Hansen

Thursday May 24, 2012

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Table Of Contents

Cover Page 1

Table of Contents 2

Executive Summary 3

Prototype Diagram 5

Service Manual 6

Results 10

Bill of Materials 12

Conclusion 16

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Executive Summary-

For our project we were tasked with designing the electrical system for a prototype car.

We needed to create a keyless entry, seatbelt sensor, motor system, car horn, windshield wipers,

directional signals, brake system, a rear obstruction sensor and a subsystem enhancement. For

the enhancement we were given a list of add-ons that we could make to make our product better.

Not only did we have to create these systems, most of them needed to be integrated into other

systems so they work together (such as the three input key being needed to start the motors). For

this assignment we were required to build each system, integrate them together as requested and

debug and make it all of it work together when we were evaluated on the due date.

In our time spent we were able to create the desired systems, integrate them and have

them run efficiently and with the simplest design. This design was optimal because it was easy to

produce, easy to debug and had a quality wiring job that made replacing burnt out components a

breeze. With the neatness of the circuit in addition to the simplicity of the systems our product

would undoubtedly be the preferred solution. Once we completed the initial builds of the system

we went back to test each subsystem and did a thorough debugging, fixing problems with the

motors, horn and other subsystem. While did this we spent large amounts of time cleaning up the

wiring, and looking for ways to make circuits simpler and more efficient. For our subsystem

enhancement we created a radio tuner, which can cycle through ten radio stations and would be a

very positive addition to our system. Most people who drive tend to use their radio more than

their wipers and headlights so a radio station tuner would be something that the majority of car

buyers will be looking for.

Subsystem Points Maximum

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Name EarnedPoints Possible

Motors 20 20Brakes 15 15Wipers 10 10Headlights 11 20Rear View 20 20Horn 10 10Turn Signals 13 15Keyless Entry 10 10Seatbelt Sensor 10 10Radio Tuner 16 20Neatness 20 20Total 155 170

Cost of Subsystems

Subsystem

Total Cost

Motors 5.3

Radio 4.26Brakes 2.72Seatbelt Sensor 2.45Horn 1Headlights 2.1Turn Signals 4.08Keyless Entry 2.94Wipers 50.5

Rear Obstruction Senor 1.11Total 76.46

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For the production of this product, the carbon footprint is pretty minimal. We didn’t have

to transport it so we created 4480 kilograms of CO2 in the manufacturing and 1540 kilograms of

CO2 in disposal for a total of 6030 kilograms of CO2. This figure might be high because we are

unsure if any of the parts are recyclable, because if they are the projected number will be even

lower.

Prototype Design:

This prototype layout will be intuitive and easy to use for multiple reasons. The first

reason would be that the wiring is extremely neat. There are no flyovers every wire is as close to

the board as possible and wires going across the board go under and pop back up on the other

side where they fit into their component. This is very helpful to the user and saves a lot of time

that would have been spent looking for a specific input or output or trying to find where a

specific wire goes if it becomes unplugged. The second factor that this layout is optimal would

be that all of the integrated circuits can be easily replaced. There is nothing over them, next to or

overlapping them and even a novice could pull one out and replace it with a replacement part.

This is a breath of fresh air compared to other prototypes, where if you needed to replace a

component you couldn’t because of all of the wires and other parts overlapping or neighboring it.

The third and final reason our layout is that all of the input switches and output indicators are

clearly labeled in their respective key. This speeds up operation time and makes sure the

technology incompetent users don’t accidentally push the wrong button. With these three factors

working together it can easily be seen that our prototype is extremely user friendly and can be

easily handled by the average person.

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Service Manual:

Wipers:

This is by far the easiest and most expensive component of the entire project. We used a

Board of Education, a switch and a servo motor. We had the board of education running our

wiper program (as shown below) with the input of the servo hooked to the specified port. We

then hooked one end of the switch to Vcc and hooked it in series with the red wire of the servo

motor. We then connected the black wire to ground to complete the circuit. This way when we

flipped the switch on, it completed the circuit and the wiper (aka the servo) turned back and

forth. Here is the specific program we used:

' {$STAMP BS2}

OUTPUT 12 'connected to servo motor

OUT12=0 'start with the control line low.

n VAR Byte 'byte size variable (0-255) used in the for loop

' this loop rotates the servo motor fully clockwise.

loop: ' line label so program can return here .

FOR n = 1 TO 15 ' repeats loop 15 times to send 15 pulses to the servo

PULSOUT 12, 500 ' sends a high pulse to the serco with a duration

'of 500 x 2 us = 1ms. pulses of this

'width will drive the servo to fully clockwise

PAUSE 20 ' servo requires 20 ms betweenb pulses

NEXT

DEBUG CLS, "Serco position:fully clockwise" 'cls clears the screen

FOR n = 1 TO 15 ' repeats loop 15 times to send 15 pulses to the servo

PULSOUT 12, 750 ' sends a high pulse to the serco with a duration

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'of 750 x 2 us = 1..5ms. pulses of this

'width will drive the servo to the midpoint

PAUSE 20 ' servo requires 20 ms between pulses

DEBUG CLS, "servo position: Midpoint"

'This loop rotates the servo motor to the fully counterclockwise position.

FOR n = 1 TO 15 ' repeats loop 15 times to send 15 pulses to the servo

PULSOUT 12, 1000 ' sends a high pulse to the servo with a duration

' of 1000 x 2 us = 2000 ms. Pulses of this width

' will drive the servo fully counter clockwise.

PAUSE 20 ' servo requires 20 ms between pulses

NEXT

DEBUG CLS," servo position fully counterclockwise"

GOTO loop

Headlights:

For this system we started out with a triple input NOR gate. This wasn’t our preferred

chip, however the cabinet didn’t have triple input OR gates. We then took a output from the

switch of the wiper, a switch designed specifically for the headlights and a phototransistor

hooked up to 5V. These three made up the inputs of the headlights. We then took the output, and

put it into three other NOR inputs to invert it into a Triple input OR gate without using an

inverter. We then took the output of that and hooked it in series with the red wire of the AC

power supplier and hooked the black wire into ground. With this setup when any input goes high

the chip will output high turning on the AC power supply and lighting up the light bulb.

Radio Station Selector:

For this we used the model that we used in class. This model consisted of a 74LS93

hooked up as a MOD 10 counter, a 74LS47 Decoder, a 4116RCF 470 Ohm resistor chip and a

FND507 seven segment display. To simplify it, we hooked up a push button on the board instead

of using the one on the trainer. We then hooked up the pushbutton to the counter, whose output

was hooked up to the 74LS47 decoder, whose outputs went through the 470 Ohm resistor chip

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and into the seven segment display. This way when the pushbutton was pushed, it would cycle

through the ten stations on the display.

Horn:

This subsystem was relatively simple, but it took us a long time to get working properly.

We just took a AND gate and an OR gate and a pushbutton. We had the output of the backup

sensor and the output of the pushbutton, put them in the OR gate whose output went into the

AND gate. While in the AND gate it is combined with the Clock signal to output a frequency if

the horn or the Distance sensor go off. We took the output of the AND gate and ran it through

the speaker with the other part of the speaker going to ground.

Seatbelt Sensor:

This was another simple design that was built around the H2A1 photo interrupter. We

simply hooked up the photo interrupter as shown in the lab packet with the red led hooked up in

series with the output of the receiver. This way when something blocks the photo interrupter the

current flow stops turning off the LED and signaling that the seatbelt is buckled.

Rear Obstruction Sensor:

This system was another of the many simple systems used in our prototype that makes

our design easy. We used the sensor attached to the wooden chassis and hooked the red wire to a

comparator and potentiometer in series to 5V and the black wire to ground. We used the

comparator and potentiometer to regulate the distance that it senses and tuned it to 10 cm. We

then hooked up the output of the sensor into the brakes, motors and horn.

Three Switch Keyless Entry:

For this we used two D flip flops and based our design of the model in lab 8. If you press

D then CLK the Q output will put out a constant high. We hooked two together to make it a three

switch entry and hooked the outputs (Q and Q NOT) to LEDs. For extra security we hooked up

the Q output to an AND gate with the input of the motors, so if the wrong sequence is entered the

motors won’t start.

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Brakes:

This was another system that we made simple for ease of use. We hooked up a

pushbutton and put in a RED LED that would light when it was pressed. We then took the output

and inverted it and put it in an AND gate with the Q output with the input for the motors. With

this setup when the motors are running and we push the brakes the red led comes on and the

motors stop.

Turn Signals:

For the turn signals we ended up using a more complex design. We had three push

buttons (one for left, one for right and the third for reset) hooked up to flip flops that would give

a high Q when their button was pushed. These Q outputs were hooked up to AND gates with the

clock signal, and then put into LEDs. When both buttons were pressed the flip flops reset each

other and it causes the red LED to light. This can then be shut off by pressing the reset

pushbutton.

Motor:

This is by far the most complex system out of the whole project. We used the motor

design from the dual motor control lab. We then took this model and integrated the Three switch

keyless entry, the brakes and the backup sensor so it wouldn’t work unless the conditions of the

other systems were met. We then hooked the motors up to two switches so they would go

forward or reverse.

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Results:

Our testing went well but not as well as we hoped. Our phototransistor for our headlights

had been working fine the night before, but for some reason stopped working on our testing day.

Although we tried to debug it, we didn’t have enough time to fix the problem before we had to

test so we lost the majority of the points that we didn’t get there. Another problem was that our

turn signal and horn were hooked up to run on the same frequency. This was detrimental because

for optimal performance the turn signals and the horn needed to be hooked up at different

frequencies to receive full credit so we ended losing points there as well. The third place we lost

points was on the radio tuner, where when you pushed the channel selector button it occasionally

jumped multiple stations when it should have only changed one. We could have fixed this by

running it through a Schmitt inverter which would have cleaned up the signal and made sure it

only changed one channel at a time. Those were the only places that we lost points and overall

we did very well on the testing phase.

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Names Paul Hansen Glenn Trost__________________________________________Point Total (170 max) ____155____

1. Keyless Entry: Motor Activated & Green LED On (5) __5_____

Motor Lockout & Yellow LED On (5) ___5____Keyless Entry Total (10) __10_____

2. Seatbelt Sensor: Red LED On if "Buckle" Not Inserted (10) ___10____Seatbelt Total (10) ____10___

3. Horn: High Pitched Sound when Button Pressed (5) ____5___

Sounds when Rear Obstacle Detected (5) __5_____Horn Total (10) ____10___

4. Headlights: On when Toggle On (5) ___5____

On when Ambient Light Level is Low (10) __1____

On when Wiper is On (5) __5_____Headlight Total (20) __11____

5. Windshield Wiper: Rotates Back and Forth When Toggle On (10) _10_____Wiper Total (10) ____10___

6. Directional Signal: Left Green LED Blinks at Low Rate only if Left Switch Pressed (5) __5____

Right Green LED Blinks at Low Rate only if Right Switch Pressed (5) __5_____

Red LED Blinks at Low Rate if both Left and Right Switches Pressed (5) __3____

Signal Total (15) ___13___

7. Motor: Off Anytime Switches are in the Neutral Position (working motor) (5) _5_____

Spins Forward with Switches in Forward Position & Activated (5) __5_____

Spins Backward Switches in Forward Position & Yellow Backup Light on (10) _10____

Motor Total (20) ___20____

8. Brake: Red LED On when Brake Button Pressed (5) __5_____

Motors Off when Pressed (Forward & Reverse) (10) ___10___Brake Total (15) __15____

9. Rear ObstructionSensor: Red Brake LED on when Object < 10cm (Forward or Reverse) (5) ___5____

Horn on only if Motor in Reverse and Object < 10cm (5) __5_____

Motor Goes Off only if in Reverse when Object < 10cm (10) ___10____Rear Obstruction Total (20) _20_____

10. Subsystem Name of Subsystem(s) ______Radio Tuner__________________________Enhancement: Comments:

Subsystem Enhancement Total (20) ___16___

11. Circuit Neatness: Good Layout, Well Labeled, Neat Wiring Circuit Neatness Total (20) ___20___

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Bill Of Materials

Part Name VendorPart Number

Quantity

Unit Price

Totals Per Part

Dual D-type pos.-edge-triggered flip-flops TI 74LS74 4 0.38 1.52Quad 2-input positive-OR gates TI 74LS32 2 0.38 0.76Quad Differential Comparator TI LM339n 1 0.11 0.11Quad 2-input positive-NAND Schmitt triggers TI 74LS14 2 0.4 0.8Quadruple 2-Input Positive-AND Gates TI 74LS08 3 0.37 1.11Triple 3-input positive-NOR gates TI 74LS27 1 0.41 0.414-Bit Binary Counters TI 74Ls93 1 1.9 1.9BCD-to-Seven-Segment Decoders/Drivers TI 74LS47 1 1.15 1.15Quadruple Half-H Drivers TI SN75441 1 0.75 0.75Single, Current-Limited, Power-Distribution Switch TI PS2051 3 0.6 1.8Hex inverter buffers TI 74ls06 1 0.55 0.55470 Resistor Chip Digi Key 4116RCF 1 0.76 0.76

Push button parallax 7 0.1 0.7

7 Segment DisplayFuturlec i7208D 1 0.35 0.35

Green LED Parallax 3 0.5 1.5Red LED Parallax 3 0.5 1.5

Yellow LED Parallax 1 0.5 0.5

100k Potentiometer 1 1.5 1.5

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Photo-transisitor Parallax 1 1.49 1.49

Photo- Interrupter Parallax H21A 1 1.5 1.5Diode Parallax 3 0.2 0.62k Resistor Parallax 2 0.15 0.3470 Resistor Parallax 14 0.15 2.11k Resistor Parallax 3 0.2 0.610k Resistor Parallax 7 0.2 1.4.14 Pf capacitor Parallax 2 0.15 0.3Basic Stamp Parallax 1 50 50switch Digi Key 1 0.5 0.5

76.46

SubsystemsMotorsQuadruple Half-H Drivers SN75441 1 0.75 0.75Hex Inverter Buffers 74LS06 1 0.55 0.55Single, Current-Limited, Power-Distribution Switch Ps2501 3 0.6 1.8470 Ohm Resistor 6 0.15 0.910k Resistor 5 0.2 1.14uf 2 0.15 0.3

Total Cost 5.3

Radio470 Resistor Chip Digi Key 4116RCF 1 0.76 0.76

BCD-to-Seven-Segment Decoders/Drivers TI 74LS47 1 1.15 1.154-Bit Binary Counters TI

SN74LS93 1 1.9 1.9

7 Segment DisplayFuturlec i7208D 1 0.35 0.35

Push button parallax 1 0.1 0.1Total 4.26

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CostBrakesRed LED Parallax 1 0.5 0.5Quadruple 2-Input Positive-AND Gates TI 74LS08 1 0.37 0.37Quad 2-input positive-NAND Schmitt triggers TI 74LS14 2 0.4 0.8470 Ohm Resistor 1 0.15 0.1510k Resistor 1 0.2 0.2Diodes Parallax 3 0.2 0.6Push button parallax 1 0.1 0.1

Total Cost 2.72

Seatbelt SensorRed LED Parallax 1 0.5 0.5Photo- Interrupter Parallax H21A 1 1.5 1.52k Resistor Parallax 1 0.15 0.15470 Resistor Parallax 2 0.15 0.3

Total 2.45

HornQuadruple 2-Input Positive-AND Gates TI 74LS08 1 0.37 0.37Quad 2-input positive-OR gates TI 74LS32 1 0.38 0.38Push button parallax 1 0.1 0.1470 Resistor Parallax 1 0.15 0.15

Total 1HeadlightsTriple 3-input positive-NOR gates TI 74LS27 1 0.41 0.41Photo-transisitor Parallax 1 1.49 1.491k Resistor Parallax 1 0.2 0.2

Total 2.1Turn SignalsDual D-type pos.-edge-triggered flip-flops TI 74LS74 2 0.38 0.76Quad 2-input positive-NAND Schmitt triggers TI 74LS14 1 0.4 0.4Quadruple 2-Input Positive-AND Gates TI 74LS08 1 0.37 0.37

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Push button parallax 3 0.1 0.3

1k Resistor Parallax 3 0.2 0.6470 Resistor Parallax 1 0.15 0.15

Green LED Parallax 2 0.5 1Red LED Parallax 1 0.5 0.5

Total 4.08Keyless EntryDual D-type pos.-edge-triggered flip-flops TI 74LS74 2 0.38 0.76Quad 2-input positive-OR gates TI 74LS32 1 0.38 0.38Green LED Parallax 2 0.5 1Yellow LED Parallax 1 0.5 0.51k Resistor Parallax 1 0.2 0.2Push button parallax 1 0.1 0.1

Total 2.94WipersBasic Stamp Parallax 1 50 50switch Digi Key 1 0.5 0.5

Total 50.5Rear Obstruction SensorQuad Differential Comparator TI LM339n 1 0.11 0.11100k Potentiometer Digi Key 1 1 1

Total 1.11

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Conclusion:

Overall our design is very strong. It is simple, easy to fix and it is easy for someone who

isn’t technically gifted to operate. This is the optimal solution to the problem because it is very

user friendly and is more catered more towards the average customer. With that we included the

radio station selector because the average driver listens to the radio and by including it we make

our system even more desirable to the average driver.

However even with all of our success we did have some shortcomings. For one we had a

lot of trouble keeping everything working at the same time, with problems arising and more

problems taking their place when they were fixed. We could have improved on this if we were

given another chance, by spending more time debugging and giving extra care not to mess up

any of the working systems. By having more time to test and debug we would have been able to

improve our score on this project.

Overall our cost was good for the time we had to create this project. We made things

simple and tried to use as few chips as possible when creating the circuit. A few major areas

where we could have saved money would be for one the wipers; we would have been able to

save fifty dollars of our total cost if we were able to circumvent the use of the stamp for turning

the wipers. Another area we could have saved would have been the turn signals, where we could

have used a greatly simplified version of it, but had a disagreement about it and ended up using a

more complex version that holds the signal but uses three more chips. The final way we could

have reduced the cost would have been by utilizing our space better. If we had the time to

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reorganize everything to fit better we could have saved a board a few chips and a lot of wire.

However with the constraints we were under we didn’t have time to do this.

For the sustainability analysis we used 4480 kilograms of CO2 in the manufacturing and

1540 kilograms of CO2 in disposal for a total of 6030 kilograms of CO2 over its entire life. As

stated previously if we had the time we could have cut out a board which would have greatly

decreased the impact of the lifecycle of this product.

The Restriction of Hazardous Substances Directive or RoHS is a directive created by the

European Union to restrict the presence of hazardous substances in an array of products. The six

substances that were restricted were Lead, Mercury, Cadmium, Hexavalent chromium,

Polybrominated biphenyls (PBB) and Polybrominated diphenyl (PBDE) ether. Below is a table

of the compliance of each specific subsystem:

MotorsCompliant

Turn Signals Compliant

BrakesCompliant

Keyless Entry Compliant

WipersCompliant

Seatbelt Sensor Compliant

HeadlightsCompliant

Radio Tuner Compliant

Rear ViewCompliant Horn Compliant

Overall since all of the components we purchased came from a supplier that complies with

RoHS we were able to create a system that fully complies and has no issues with these

restrictions. This is beneficial for marketing in other countries and also should enforce your

decision that our product is the optimal choice for your company.