Lab 1:
Name,NetID: Diego Gutierrez, dgutie34 , Yogesh Ramani, yogeshr2
Lab 1.1: 8/29/2022 Lab 1.2: 9/12/2022
Due Date: 9/19/2022
Lab 1.1 - Fritzing
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Statement of Purpose:
Install Fritzing and the ECE 206 libraries, use them to create a version of your NE555 circuit
from Lab 1.2 to include with your lab report.
Plan:
In this portion of the lab we use online software to simulate a circuit on a breadboard. Since this
is an introduction lab, we spent most of the time learning how the software works. All of the
required software can be found on the ECE wiki.
Figure 1: Arduino Used
Figure 2: Default Breadboard layout
Execution:
The following is the completed schematic created using Fritzing.
Figure 3: Completed 555 Timer Circuit Schematic
Figure 4: Breadboard of 555 Timer Circuit
Results and Conclusion:
In this lab we were able to gain an understanding of the Fritzing, setting us up for our
next lab where we will physically construct this circuit. This also being my first time working with
any kind of arduino/breadboard, the software allowed me to gain some understanding of their
function.
Lab 1.2 - 555 Timer and Nano Every
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Statement of Purpose:
Construct an astable multivibrator(oscillator) circuit and use the Arduino Nano Every to
confirm/deny that R2 determines the discharge time, but R1+R2 determines the charge time.
Plan:
Since we had already created a schematic and breadboard layout all that was required was to
physically build the circuit. The schematic (Figure 3) proved to be most useful as it had all the
connections and pins on it. The 2-D breadboard (Figure 4) could be hard to understand since
wires overlap and like in our case, not everything was correct. We had to make adjustments
from the online breadboard, but it was only a small issue that was easily fixed as we built the
physical circuit. Additionally the lab asked for a 20kOhm resistor, but the highest resistance in
the lab kit was 10kOhms so we put two 10k resistors in series.
Figure 5: Breadboard R1=10k Ohms Configuration
Execution:
Now using the Arduino Nano Every and the Arduino software we measured the voltages
indicated Vout and Vin in the diagrams.
Figure 6: Oscilloscope for R1 = 10k Ohms
Figure 7: Oscilloscope for R1 = 20k Ohms
Results and Conclusion:
We used A0 and A1 to measure Vout and Vc. We need to use analog inputs because we are
using the capacitor as a way to tell the circuit what to do. As explained in lab manual 1, C1
voltage bounces between the upper threshold of 2/3 Vcc (5V) and the lower threshold of 1/3
Vcc. We can control the charge time of the capacitor using R1 and R2. We can also control the
discharge time using R2. If we used digital the 0 could be 0V on the capacitor and 1 could be
5V. I think the issue is that the behavior of the capacitor, as it reaches either end, would take a
very long time. As exponentials are used to model capacitors, it would in theory never reach 0V
or 5V as those are the asymptotes.
In both figure 6 and 7 the discharge time of the capacity remains constant. The exact interval is
difficult to read off of the graph, but knowing each square is equal to 100 units on each graph,
the discharge interval length is identical.
When looking at the charge time of the capacitor it is very easy to see how they differ. The
circuit with R1 value of 10k Ohms takes about twice as much time to charge than to discharge
while the circuit with R1 value of 20k Ohms takes about three times as much time to charge
than to discharge.
Through this lab I learned how to more appropriately design a breadboard to be not only
functional but simply built. It also provided insight into why analog inputs are useful and how
they are different from digital inputs.