Download Logic Design Board

Logic Circuit Teaching Board
By
Andrzej Borzecki
David Lee
Younas Abdul Salam
Final Report for ECE 445, Senior Design, Spring 2015
TA: Ankit Jain
Group 3
Abstract
The goal of this project is to develop an educational board to introduce Electrical
Engineering and logic design to young students, and spark an interest for the field. The function
of this project is to facilitate teachers in high schools with explaining how circuit design works
and provide as a visual aid. It can also be used by students to obtain hands on experience in a
safe environment. The educational board teaches logic design by allowing the user to create their
own truth table and build a gate level circuit that matches the truth table. The board detects when
the user has correctly matched the truth table inputs with the gate level design. It is also capable
of identifying which row in the truth table is incorrect if the user is unable to build a matching
circuit.
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Contents
1. Introduction ................................................................................................................................. 1
2 Design .......................................................................................................................................... 2
2.1 Design procedure................................................................................................................... 2
3. Requirements and Verification ................................................1Error! Bookmark not defined.
4. Costs.......................................................................................................................................... 18
4.1 Parts ..................................................................................................................................... 19
4.2 Labor ................................................................................................................................... 19
5. Conclusion ................................................................................................................................ 19
5.1 Accomplishments ................................................................................................................ 19
5.2 Uncertainties........................................................................................................................ 19
5.3 Ethical considerations ......................................................................................................... 20
5.4 Future work ......................................................................................................................... 20
References ..................................................................................................................................... 21
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1. Introduction
Most of electrical engineering students are introduced to logic circuit design as one of the first
classes in their undergrad curriculum. Having to learn logic design techniques as well as working
with actual chips can become very overwhelming for some students. We realized that many
young students would benefit from having an early background in logic design, and this can only
be achieved by making a much simpler board for them to use. The purpose of the board will be
to help student’s get exposed to logic design earlier, and only have to concentrate on the
important aspects. Finding an area of interest for young students to pursue in education is
important, and our educational logic board will promote an excitement towards Electrical
Engineering. It can help to remove the intimidating image of Electrical Engineering and help
student be more prepared and have a better understanding. This would not only facilitate them
into deciding electrical engineering as their future field, but will also demonstrate how fun and
satisfying the career path can be. Ultimately, this has the potential to benefit nationally as well as
on a global scale Figure 1 has the overall design of the project.
Power
Truth Table Board
Truth Table Switches
Green LED
Power
Microcontroller
Power
Supply
Red LED
Logic Design Board
Logic Design Pieces
Power
Figure 1
Name
Title
Date
1
Younas Abdul Salam
Block Diagram of Overall Design
5/6/2015
2.0 Design
2.1 Design procedure
Power Supply
We used a power supply to power the board and its components. It produces a voltage that is
used to provide power to the TTL logic components and LEDs on the board and to power the
microcontroller used to test the truth table. The supply takes in 120VAC as an input from the
power outlet in the wall and inverts and transforms the voltage to the 5VDC required for logic
design, within a tolerance of +/- 0.5VDC. The power supply is connected to the board and the
microcontroller directly. Using banana plugs, it powers the logic gates connected to it, with a
Vdd and Gnd connection. The power supply is also connected to the logic components to power
them for use. The ground port of the power supply is connected to the truth table switches, as
shown in Figure 5.
The calculation for the amount of current required are as follows:
15 LEDs from logic components: 15*~20mA=300mA
15 logic gates inside the components: 15*~3.5mA = 52.5mA
2 selection logic components: 2*~8mA = 16mA
Arduino UNO MCU: ~400mA based on the number of ports being used = 400mA
Total current = ~800mA
To be safe, we use power supply with at least 1.0A.
Truth Table Board
The truth table board is used to implement the truth table that the user wants to input and test.
Using the switches attached to the board, the user inputs a desired truth table. Then the user
attempts to build the logic design that matches the board using the logic components. The
switches that allow the user to input the desired truth table are connected to a MUX on one side,
and Vdd/GND on the other, as shown in the Figure 2. This way, the microcontroller can
communicate with the logic shown on the truth table by inputting the selection logic of what
value it is trying to read, and then checking what the truth table value is at that location. The
board has the capability of hosting up to three inputs, and the corresponding output. The truth
table board is a 9x5 grid that holds the truth table on the user’s right side of the logic design
board as shown in Figure 2. Additionally the user has the option of specifying how many inputs
2
should be checked using a switch, and the microcontroller can then pick up the values
accordingly.
Logic Design Board
The logic design board is used to hold the TTL logic components and the user input truth table
for logic design on the surface of the board. The power supply, programmed microcontroller and
necessary control circuitry are located below the user interface and mounted to the bottom of the
board as shown in Figure 3. This allows the user a visually appealing user interface without the
unnecessary distraction of components which may confuse the user. The board consists of an
array where each position in the array contains two banana plugs and a polarity hole. The red and
black banana plugs are used to supply 5Vdc and 0Vdc, respectively. The polarity hole ensures
that the user places the logic design pieces on the board correctly in order to prevent the user
from plugging in the TTL components in reverse polarity causing the logic pieces to malfunction
and risk the possibility of damaging the component.
Figure 4 shows the initial board design and sizing. The initial length and width of the board
were 44cm and 30cm, respectively. The initial design included an array of T plugs, shown in
Figure 2. The initial design used T plugs as the interface between the logic design board and the
logic pieces being plugged into the board. Because of the lack of durability and inconsistency of
the size of the T plugs we decided the design would be easier and more robust by using banana
plugs as the connection ports. Banana plugs are both versatile and durable, and used throughout
the engineering industry for easy connections. The change in the connection also caused us to
change the size of the board. The final length and width of the board are 60cm and 100cm
respectively. The array dimensions were also changed from an array that consisted of 3 columns
and 5 rows to an array that has 5 columns and 3 rows. This was an important change because of
the decrease in voltage drop caused by the series resistances where the pieces are plugged in. In
order to maintain the desired voltage at each of the banana plugs this changed needed to be
implemented.
In order to connect each slot, the board will have wired connections with banana plugs to make
connections between TTL logic components. The logic design board will allow the user to
manually test the inputs and output of the truth table by using the banana plugs connected to the
side of the board labeled Vs, GND, A, B, C and Y. These will be female connections that allow
the user to add power to the board and test inputs and outputs by physically plugging in high and
low voltages into A, B, C and reading an output from Y. This gives the board versatility because
it allows the user to test partial circuits on the board by inputting outputs to different parts of the
board.
3
4
5
Microcontroller
The purpose of the microcontroller is to implement the various functions possible to assist
students with logic design. One of the key functions of the board is the logic tester, which will
test whether the student has implemented correct logic according to the truth table. Many other
functions are possible, some of which will be mentioned later. Since this board is also open
source, any developer can modify the existing functions or add new functions to the board using
the microcontroller.
The microcontroller is connected to almost all the components in the board, as shown in Figure
6. This helps give complete access to any developer and also helps with debugging, which is a
feature that will be discussed later.
6
Figure 6
Name:
Title:
Date:
Younas Abdul Salam
MCU connections
5/6/2015
One of the main components is the power circuit used to power the microcontroller. Since the
microcontroller requires a voltage of at least 6V to function properly, whereas the voltage from
the power supply is 5V, a voltage booster circuit was used. By utilizing a MAX680 voltage
booster, the input voltage to the microcontroller was increased above 6V, thus allowing proper
functioning. Figure 7 shows the schematic and actual implementation of the circuit. The
maximum capacitance allowed in the datasheet is 22uF, which is what was used to be able to
provide maximum current without lowering voltage by a significant amount. However, even with
the maximum amount of capacitance allowed, the microcontroller could not be used to directly
power LEDs, as the voltage drop risked forcing the microcontroller input voltage to lower than
6V. Figure 8 is a graph of the input voltage measured versus the number of LEDs simultaneously
being powered by the microcontroller. As can be seen, having one LED turned on reduces the
voltage to close to 5V, and having two on lowers it below 5V. The solution of this problem is to
connect the LEDs through NOT gate buffers. The microcontroller therefore only has to provide
voltage with a small amount of current. The amount of current required to turn on the LED is
provided by the gate, which is receiving power directly from the power supply. The circuit for
the LED is as shown in Figure 9. We used a double colored LED which turned on either Red or
Green, depending on the polarity of voltage across the inputs.
7
Voltage vs # of LEDs
7
Voltage (V)
6
5
4
3
Voltage
2
1
0
0
0.5
1
1.5
2
2.5
Number of LEDs
Figure 8
Name:
Title:
Date:
Younas Abdul Salam
Voltage vs # of LEDs
5/6/2015
Figure 9
Name:
Title:
Date:
Younas Abdul Salam
LED buffer
5/6/2015
Another design variation we had to implement was to correct for floating inputs from the
switches to the microcontroller. Normally, such issues are resolved by using a resistor and a
switch in series. However, to limit the amount of current drawn due to a path from Vdd to Gnd in
this set up, we decided on using TTL chips. TTL chips are designed to treat floating inputs as
HIGH. If we use a NOT gate, then the normal OFF position of the switch sends a LOW voltage
to the output, as a floating is considered a HIGH input and converted to a LOW output. If the
switch is connected to Gnd, then the NOT gate will change the output to HIGH, which is how we
want it to function. Figure 10 shows the connection between the switch and NOT gate, and how
this is implemented.
8
Figure 10
Name: Younas Abdul Salam
Title: Switch buffer
Date: 5/6/2015
The final hardware variation required for the microcontroller was a 8-to-1 MUX to read inputs
from the switches and turn on the computational LEDs to assist the students with designing. Due
to limited number of ports on the microcontroller, it is not feasible to connect all eight switches
directly to it. Therefore, using a MUX, specific switches can be read by adjusting the selection
logic. Figure 11 shows is a connection diagram of how this is implemented. Furthermore, this
helps turn on the computational LEDs as desired, without having to implement extra circuitry for
them. Each value of the selection logic corresponds to an LED, and therefore the LEDs can be
controlled using the same outputs from the microcontroller. In order to prevent the LEDs from
turning on when switches are being read, an enable signal is added.
Figure 11
Name:
Title:
Date:
Younas Abdul Salam
Switch + MUX
5/6/2015
As discussed earlier, the main feature implemented by the microcontroller is to test the logic
designed by the student. The flow chart for the code is shown in Figure 12. When the user wants
to run the test function, he will press a button on the board linked to the microcontroller,
signaling it to begin the testing. The microcontroller will first figure out how many inputs the
user wants to use by reading the switch, and adjust the number of cycles accordingly. The
microcontroller will then start running tests on the truth table values by reading the values in the
truth table, and simultaneously testing the board logic to make sure it is correct. To read the
outputs of the truth table one at a time, the 3-bit selection logic signal will be sent to the MUX
and that output will be outputted by the MUX and will be fed into the microcontroller. If the
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result is incorrect, the user will be notified by a Red LED and the program will stop. If the result
is correct, the microcontroller will keep testing until the loop has run, and turn on a Green LED
indicating that all values are correct.
BEGIN
Check
# of inputs
Send 3-bits to
decision
inputs
Output
from Truth
Table
Pick up
Output
Send
appropriate
BC logic
value
2
# of
inputs?
3
Send
appropriate
ABC logic
value
1
Send
appropriate C
logic value
Increment
bits to
decision and
rest of logic
Output
from Logic
Board
Pick up
output logic
Correct but values remain to
be checked
Check with
truth table logic
Correct and all relevant values
checked
END
Incorrect Red LED ON
END
Green LED
ON
Figure 12
Name
Title
Date
Younas Abdul Salam
Flow Chart for Microcontroller Program
5/6/2015
Additional features that have been created for the microcontroller are hardware debugging and
minimum number of gates required. The hardware debugger can be used to test the function of
the hardware components to ensure they are working correctly. All data will be displayed on the
Arduino serial output, as shown in Figure 13 and Figure 14. Figure 13 is a complete run through
without any errors, and Figure 14 is a purposely induced error to demonstrate how it would
function. The operation of the board must be consistent with what the user has input, and any
hardware discrepancies can be determined using this code. The second feature is the number of
gates feature, which can be used to challenge students. It displays on the board as well as through
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the serial input, the minimum number of gates the truth table can be implemented in, as is shown
in Figure 15.
Figure 13
Name:
Title:
Date:
Figure 15
Younas Abdul Salam
All logic correct
5/6/2015
Name:
Title:
Date:
Figure 14
Name:
Title:
Date:
Younas Abdul Salam
Error in logic
5/6/2015
Younas Abdul Salam
Number of gates
5/6/2015
Logic Design Pieces
The logic design pieces hosted the components that are essential to making the pieces easy to use
and provide relevant logic information. Each one of the pieces had a gate and a LED connected
to the output. The LEDs conveyed the logic output of the piece to the user, so it was easier to see
the logic flow through the created circuit and also assisted in debugging. The power connectors
were plugged into the logic board directly when the piece was plugged in, in order to power the
chip and LEDs.
Each one of the logic pieces were shaped as the logic element they represented, this way it was
easier for the user to keep track of the gates used for the desired circuit. Some of the other
possible designs for the logic pieces were to keep them all shaped the same and draw the gates
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on top of each piece. If we would have chosen this design, it would have made 3D printing less
strenuous but it would not give the optimal user experience when trying to learn logic design.
Therefore we decided to 3D print logic units shaped as their respective gate inside. Below
figures 16 through 18 represent the final shapes of the logic pieces.
Figure 16
Name
Title
Date
Figure 18
Figure 17
Andrzej Borzecki
AND Gate 3D
6/6/2015
Name
Title
Date
Andrzej Borzecki
NOT Gate 3D
6/6/2015
Name
Title
Date
Andrzej Borzecki
OR Gate 3D
6/6/2015
Each of the logic pieces hosted an integrated circuit that were essential to making the pieces easy
to use and provided relevant information to the user. Each one of the logic pieces had an output
LED which provided information to the user on the state of the, which was either high or low.
The circuit schematics are provided below in figures 19 through 21.
Figure 19
Name
Title
Date
Figure 20
Andrzej Borzecki
AND Gate Schematic
2/23/2015
Name
Title
Date
Figure 21
Andrzej Borzecki
OR Gate Schematic
2/23/2015
Name
Title
Date
Andrzej Borzecki
Inverter Schematic
2/23/2015
In order to ensure the reliability of the LEDs on the logic pieces we had to calculate the optimal
size of the resistor to limit current flowing through the resistor. Our calculations went as follows:
R = V/I = (5 - 3.5) / 0.02 = 75 Ohms ------------------------------------------------------------------- (1)
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I (mA) vs V
I (mA)
40
20
I (mA)
0
0
2
4
6
Voltage (V)
Figure 22, I/V curve for green output LED.
3.0 Requirements and Verification
Requirement
Verification
Points
1. Power Supply
1. Supply 5V +/- 0.5V to the
board components
1. Test the output voltage and current of the
power supply:
a) Plug the power supply into the power
outlet on the wall which supplies 120Vac.
b) Close the power supply safety(flip to on
position)
15
c) Using a voltmeter probe the output of the
supply. The voltage on the voltmeter
should read 5+/-0.5V.
2. Board current is limited to
less than 1.5A
2. Check the current drawn by the board:
a) Connect an ammeter in series to the
power supply of the board.
b) Close the power supply safety(flip to on
position)
c) Disconnect all of the TTL logic
components from the board.
d) Open the switches on the top right of the
board used to set the truth table (set to 0
if they are on 1).
13
15
e) Connect the power supply of the board to
a 120Vac wall outlet.
f) Ensure that the current being read on the
on the ammeter is less than 1.5A.
g) Close the switches on the top right of the
board used to set the truth table (set the
switches to 1) and ensure that the current
being read on the ammeter is less than
1.5A .
h) Reconnect the TTL logic components to
the board and ensure that the current
being read on the ammeter is less than
1.5A.
2. Truth Table Board
1. Propagate a correct LOW (0
V) voltage to the inputs of the
multiplexer, when the switches
are in LOW position.
2. Propagate a correct HIGH (5
+/- 0.5V) voltage to the inputs of
the multiplexer when switches
are in HIGH position.
3. Propagate the correct number
of inputs information from the
switch to the microcontroller.
1. a) Set all switches to LOW position.
b) Connect a voltmeter in parallel to the input of
the multiplexer. Positive terminal must be
connected to input and negative connected to
ground.
c) The voltmeter must read 0V, meaning that the
correct voltage is being propagated.
d) Repeat test with all the inputs, and confirm
that all are getting and input 0V.
2. a) Set all switches to HIGH position.
b) Connect a voltmeter in parallel to the input of
the multiplexer. Positive terminal must be
connected to input and negative connected to
ground.
c) The voltmeter must read 5 +/- 0.5V, meaning
that correct voltage is being propagated.
d) Repeat test with all the inputs, and confirm
that all are getting the correct input voltage.
3. a) Set the number of inputs switch to 1.
b) Connect a voltmeter between the output of the
switch and ground. Connect positive terminal to
the switch output and negative to ground. This is
to reference the potential difference with respect
to ground.
c) Measure the voltage across the three outputs
14
15
from the switch.
d) The wires must output a logic 100. This
means that the first wire must have a 5 +/- 0.5V
output, while the other two must be 0V.
e) Repeat the test with the number of inputs as 2.
The logic output from the switches must be 010.
f) Repeat the test with the number of inputs as 3.
The logic output from the switches must be 001.
3. Logic Design Board
1. The output at each T-Plug
must be at 5V +/-0.5V and a 0V.
1. Test the output voltages for the TTL
components:
a) Remove all of the TTL logic components
from the board
b) Plug the power supply into a 120Vac wall
outlet so the board receives voltage.
c) Close the power supply safety(flip to on
position)
d) Starting from the top left TTL component
slot, probe the positive and negative
outputs of the T-Plug using a voltmeter.
Ensure that each T-Plug outputs 5V +/0.5V.
2. User defined banana plug
connections
e) Repeat step c) for each of the TTL
component slots on the board. The
voltmeter must read 5+/-0.5V for each
TTL component slot
2. Test the output voltages for the banana plugs
a) Plug the power supply into a 120Vac wall
outlet so the board receives voltage.
b) Close the power supply safety(flip to on
position)
c) Using a voltmeter probe the banana plugs
labeled Vs and GND.
d) The voltage between the two should be
15
10
3. Power supply safety
switch(on)
5+/-0.5V
3. Test the power supply output when the safety
switch is closed(default closed/on):
a) Plug the power supply into a 120Vac wall
outlet so the board receives voltage.
b) Close the power supply safety(flip to on
position)
4. Power supply safety
switch(off)
c) Using a voltmeter, probe the outputs of
the power supply. The voltmeter should
read a voltage of 5V +/-0.5V
4. Test the power supply output when the safety
switch is open(off):
a) Plug the power supply into a 120Vac wall
outlet so the board receives voltage.
b) Open the power supply safety(flip to off
position)
4. T-Plug connection for TTL
logic components
c) Using a voltmeter, probe the outputs of
the power supply. The voltmeter should
read a voltage of 0V meaning no
components are receiving a voltage
4. Test the connection between the TTL logic
component and the board
a) Plug in each TTL logic component into
the board
b) Flip the board upside down and ensure
that none of the TTL logic components
fall out
4. Microcontroller
1. Provide a set of instructions to
pick up values from the truth
table. Must send instructions in a
sequence to pick up the values
row by row. It must also use
these values to test the main
logic board.
1. Run microcontroller with given test program.
Press Ctrl + M in the Arduino software to open
up the serial port. The port will show all the
values of the microcontroller and what inputs
and outputs it is picking up. Run through the
whole code, with known truth table logic and
logic gate setup. Any errors will show up on the
16
30
serial port and can be used to debug the program.
The easiest method is to connect out to HIGH,
and set all truth table switches to HIGH. If the
program runs through, everything is correct. If
not, check where the program stops as that
switch might be faulty. If the program stops
before the end due to any other error, the
microcontroller may not be receiving the correct
data and that wire connection is faulty.
5. Logic Design Pieces
1. AND, OR, and Inverter gate
need to give correct logic output,
and turn on correct LEDs when
expected.
1. To check LEDs, power each in/out terminal
with a 5+/-0.5V supply, and see if the LED turns
on. Each one of the logic elements will have to
be checked separately and individually. To check
the logic is working, send in a known logic value
with known output, and see if the expected
output value shows at the output of the each gate.
AND: 00=0,01=0,10=0,11=1
OR: 00=0,01=1,10=1,11=1
NOT: 0=1,1=0
20
6. Truth Table Switches
1. Output a LOW (0V) voltage
when in the low position.
2. Output a HIGH (5 +/- 0.5V)
voltage when in the high
position.
1.a) Set all switches to LOW position.
b) Connect a voltmeter in parallel to the output
of a switch. Positive terminal must be connected
to switch output and negative connected to
ground.
c) The voltmeter must read 0V, meaning that the
correct ground voltage is being outputted.
d) Repeat test with all the switches and their
outputs, and confirm that all are giving 0V with
respect to ground.
2.a) Set all switches to HIGH position.
b) Connect a voltmeter in parallel to the output
of a switch. Positive terminal must be connected
to switch output and negative connected to
ground.
c) The voltmeter must read 5 +/- 0.5V, meaning
that the correct Vdd voltage is being outputted.
d) Repeat test with all the switches and their
outputs, and confirm that all are giving above
voltage with respect to ground.
17
10
3. Switch from HIGH to LOW
output within one second, when
switch is flipped.
4. Switch from LOW to HIGH
output within one second, when
switch is flipped.
3. a) Set all switches to HIGH position.
b) Connect a voltmeter in parallel to the output
of a switch. Positive terminal must be connected
to switch output and negative connected to
ground.
c) The voltmeter must read 5 +/- 0.5V, meaning
that the correct Vdd voltage is being outputted.
d) Flip the switch to the LOW position.
e) The voltmeter must register a LOW (0V)
output within a second of flipping the switch.
f) Repeat test with all the switches and their
outputs, and confirm that all are giving above
voltage with respect to ground.
4. a) Set all switches to LOW position.
b) Connect a voltmeter in parallel to the output
of a switch. Positive terminal must be connected
to switch output and negative connected to
ground.
c) The voltmeter must read 0V, meaning that the
correct ground voltage is being outputted.
d) Flip the switch to the HIGH position.
e) The voltmeter must register a HIGH (5+/0.5V) output within a second of flipping the
switch.
f) Repeat test with all the switches and their
outputs, and confirm that all are giving above
voltage with respect to ground.
Table: Requirements and Verification
Tolerance:
The successful operation of the complete project relies on a stable power supply output voltage.
No matter how many components have been connected, the total voltage output must not drop
below 4.5V. To check to this, plug in all the available components into the ports on the board, so
that as many ports as possible have logic gates plugged in. Also, set all the truth table outputs to
HIGH (1). Connect a voltmeter in parallel to the output of the supply, and an ammeter in series
to one of the supply voltage terminals. This is to measure the current and voltage at maximum
circuit operation. Run the logic test on the microcontroller, immediately check the voltage and
current. The voltage of the supply must not fall below 4.5V for a current less than 1.5A.
Otherwise, this is likely to affect the logic decisions made by the different logic components and
affect the performance of the product.
4.0 Cost and Schedule
4.1 Cost Analysis
18
4.1.1 Labor
Name
Younas Abdul Salam
Andrzej Borzecki
David Lee
Total
Hourly Rate
$27.00
$27.00
$27.00
$81.00
Total Hours Invested
120
120
120
360
Total
$3240 * 2.5 = $8100
$3240 * 2.5 = $8100
$3240 * 2.5 = $8100
$24300.00
4.1.2 Parts
Item
AND gates
OR gates
NOT gates
Microcontroller
Power Supply- XP
Power VEP15US05
LEDs
Banana Plugs
Banana Cables
Power Sockets
Resistors and Capacitors
Boards
8-1 MUX
1-to-3 switch
2-to-1 switch
Total
Part Number
74AHCT1G08SE-7
NC7SZ32P5X
TC7S04F
Arduino UNO
1470-2331-ND
Quantity
4
4
2
1
1
Cost
$1.00
$1.00
$0.50
$30.00
$20.00
N/A
N/A
N/A
N/A
N/A
N/A
SN74LS251N
N/A
N/A
15
35
35
15
15
2
1
1
11
$1.50
$7.00
$10.00
$20.00
$1.50
$30.00
$1.00
$1.00
$11.00
$135.50
4.1.3 Grand Total
Section
Labor
Parts
Grand Total
Total
$24300.00
$135.50
$24435.50
5.0 Conclusion
5.1 Accomplishments
We were able to successfully design and complete the project as according to our
proposal specifications. Both the board and the logic pieces passed testing as outlined in our
verification chart. We were able to successfully demo the project to our professor, peers, and
younger students who may be interested in engineering. This project has given us a great insight
19
on the product development procedures and hope it can inspire younger students to pursue
engineering.
5.2 Uncertainties
Even though our project is functioning at a high level, it is still uncertain how effective the
project would be as an educational tool. From an engineering prospective, this design has all the
capabilities of teaching logic design to the future generation.
5.3 Ethical Considerations



Complies with IEEE Code of Ethics. Product is designed to be safe under normal use,
and is thoroughly tested to ensure minimum malfunctions.
Our project is designed to improve the understanding of circuits in general, logic circuits
in particular. The following IEEE Code of Ethic applies, which states that as electrical
engineers we must help “to improve the understanding of technology; its appropriate
application, and potential consequences.”
We have thoroughly tested the working of the project, and all claims of performance are
backed by data and calculations provided. The following IEEE Code of Ethic applies,
which states that as electrical engineers, we agree “to be honest and realistic in stating
claims or estimates based on available data.”
5.4 Future Work
We left our project with an open source capability to the micro-controller located inside the
board with the hopes of it being developed per class requirement. We are also leaving the 3D
renderings as an open source so more gate pieces and larger variety of gate pieces can be made.
With this we are hoping to accomplish a larger enrollment into engineering curriculum's'.
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"74F32PC Datasheet." Fairchild Semiconductor. Fairchild, n.d. Web.
"74F14PC Datasheet." Fairchild Semiconductor. Fairchild, n.d. Web.
"Document with Confidence." AutoCAD for Mac & Windows. N.p., n.d. Web. 06 May 2015.
"About Us." Champaign-Urbana Community Fab Lab. N.p., n.d. Web. 06 May 2015.
"Machine Shop." Machine Shop. N.p., n.d. Web. 06 May 2015.
Shanahan, Patricia. "Truth Table Simplifier." Truth Table Simplifier. N.p., n.d. Web. 06 May 2015.
<http://www.patriciashanahan.com/simplify/>.
8. Maxim Integrated. "MAX680." +5V to ±10V Voltage Converters. N.p., n.d. Web. 06 May 2015.
<http://www.maximintegrated.com/en/products/power/charge-pumps/MAX680.html>.
9. "Arduino Tutorial - Lesson 4 - Serial Communication and Playing with Data." Ladyadanet. N.p.,
n.d. Web. 06 May 2015. <http://www.ladyada.net/learn/arduino/lesson4.html>.
10. Arduino. "Arduino - DigitalReadSerial." Arduino - DigitalReadSerial. N.p., n.d. Web. 06 May 2015.
<http://arduino.cc/en/Tutorial/DigitalReadSerial>.
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