ECE 363
Lab 2 Report
Fall 2015
Lab 2: Title
Your Name
Your Major, Union College, Schenectady, NY 12308
Your Minor or Second Major (if applicable), Union College, Schenectady, NY 12308
ABSTRACT
This is the template for your lab report. Except for section headings (e.g. ABSTRACT), delete all
instructions and replace with your own text. Margins are 1-inch all around. Each page should have a
header and page number. All text is in Times New Roman font with a line-spacing of 1.5. The title is
bold-faced, 18 pt, and centered. The main body text is in 11 pt font. The author entry is bold-faced and
centered. The author affiliation is also centered. The abstract should be short (seven lines or so). It
summarizes the overall goal of your lab work and what you actually did. The last sentence or two should
describe your opinion on how you benefited from the lab. The report should be roughly 3 to 5 pages.
INTRODUCTION
Briefly describe how the entire system is supposed to work. Include a figure showing a block diagram of
the entire optical heart rate monitor. Your diagram should be similar to the figure on Page 1 of the
PreLab.
DESIGN
Briefly describe the design requirement and components you used for the LED transmitter. Explain why
the LF356 is much better than the LM741 for the photodiode amplifier. Explain the purpose of the highpass filter, the filter components, and the corner frequency used for this lab. Explain why the LF356 is
much better than the LM741 for the non-inverting amplifier. Explain the purpose of the two low-pass
filters in your circuit (one in the photodiode amplifier and one in the non-inverting amplifier). Together,
do they act like a first-order, second-order, or third-order low-pass filter? Include the corner frequency.
Explain the purpose of the level shifter and the components used. You do NOT have to show any
calculations or simulations from your PreLab.
PERFORMANCE
For the LED transmitter, include the measured LED current value and whether it satisfied the design
requirement.
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ECE 363
Lab 2 Report
Fall 2015
For the photodiode amplifier, include the output error voltage and compare it to your PreLab simulation.
If they are significantly different (e.g. more than 100%), try to explain why. What do you conclude to be
the main source of output error? Hint: The LF356 has extremely tiny IIN(BIAS) and IIN(OS), so their effects
should be negligible.
For the non-inverting amplifier, explain the main source of output voltage error. Hint: The LF356 has
extremely tiny IIN(BIAS) and IIN(OS), so their effects are negligible. Also explain how you actually performed
the op amp trimming.
Include the DC offset voltage produced by your level shifter. Also include the snapshot of the heart rate
signal recorded by the Arduino-Python interface.
Overall, did your optical heart rate monitor work? Describe any strange behavior or issues encountered
during the lab (e.g. components that needed to be replaced, motion artifacts).
This was obviously a very long lab … sorry about that . Buma will certainly trim it down, but some
feedback from you would be helpful. In your opinion, what was the most time-consuming part of the lab
(e.g. too many measurements, too many op amp stages, too many tasks)?
CONCLUSIONS
Overall, did your circuit work and perform according to any design requirements? If not (and this is
perfectly OK), what lessons did you learn about the design/testing process? Also write about any concepts
or valuable lessons you learned in the lab assignment. If possible, discuss how they relate to other aspects
of the course or to circuit design in general. Your conclusion section should NOT be a summary of
your results or tasks you had performed. The conclusion is supposed to reveal what you have
LEARNED from your lab experience.
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