1. Slide design: Dr. Mark L. Hornick
SE3910
2/23/2019
SE3910 Week 3, Class 1
Today
???
Week 3 Tuesday Lab
Lab 3 was up over weekend – hopefully you downloaded the VERY BIG files.
You should have running before start of lab
Debian install (preferably on virtual machine)
Freshly flashed microSD card
Freshly flashed Beaglebone that you can ssh into
A coding assignment may be added to lab before tomorrow.
SE-2811
Slide design: Dr. Mark L. Hornick
Content: Dr. Hornick
Errors: Dr. Yoder
Dr. Josiah Yoder

2. Equipment (Reminder) Last week: Purchase 4GB or greater micro SD card
2/23/2019
Equipment (Reminder)
Last week: Purchase 4GB or greater micro SD card
Used Lab 3
(Optional) Tools – e.g. needle-noise pliers
Check out short-term
Kit (breakout board, breadboard cape, LCD cape, USB Oscilloscope)
Small parts (also may desire to purchase)
SE-2811
Dr.Yoder
Dr. Josiah Yoder

3. Exercise Select all that are real-time systems Video Game
CS2852
2/23/2019
Exercise
Select all that are real-time systems
Video Game
Aircraft Autopilot
Refinery Process Control
Cash Register
Smartphone
Discussion:
Why do we pick these options?
Are there any proceses that are not real-time?
Why does the book re-define real-time systems?
What are the practical implications?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

4. Exercise Select all that are embedded systems Video Game
CS2852
2/23/2019
Exercise
Select all that are embedded systems
Video Game
Aircraft Autopilot
Refinery Process Control
Cash Register
Smartphone
Discussion:
What is the key difference between an embedded system and a non-embedded system?
Does this clarify our answers?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

5. Ex: What is the resistance of this resistor?
CS2852
2/23/2019
Ex: What is the resistance of this resistor?
And what is the tolerance?
Dr. Yoder

6. Ex: What is the voltage across R2?
SE3910
2/23/2019
Ex: What is the voltage across R2?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

7. Ex: What’s wrong with this simple circuit’s input?
CS2852
2/23/2019
Ex: What’s wrong with this simple circuit’s input?
Work through making this input better
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

8. C, Java, C#, … unary operators
CS2852
2/23/2019
C, Java, C#, … unary operators
Increment: ++x, x++
Decrement: −−x, x−−
Address: &x
Indirection: *x
Positive: +x
Negative: −x
One's complement: ~x
Logical negation: !x
Sizeof: sizeof x, sizeof(type-name)
Cast: (type-name) cast-expression
Wiki: Unary_operation
Dr. Yoder

9. Exercise: Which of the following is correct?
CS2852
2/23/2019
Exercise: Which of the following is correct?
void foo(struct bar2* b); …
struct bar b;
And then….
foo((struct bar2*) b*)
foo((bar2*) *b)
foo((bar2*) b&)
foo((struct bar2*) &b)
This problem AGAIN has an error. b is a pointer, and yet we don’t need to de-reference it. It should just be passed straight through:
foo((struct bar2*) b)
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

10. CS2852
2/23/2019
Exercise
How do you get a reference (pointer) to the first element in an array?
int x[5] = {1,2,3,4,5}
boolean foo(int *ip);
foo(&x);
foo(&x[0]);
foo(x);
foo(x[0]);
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

11. CS2852
2/23/2019
Exercise
How do you get a reference (pointer) to the second element in an array?
int x[5] = {1,2,3,4,5}
boolean foo(int *ip);
foo(&x+1);
foo(&x[0]);
foo(x+1);
foo(x[0]);
foo(&(x+1));
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

12. Conditional Compilation
SE3910
2/23/2019
Conditional Compilation
#define DEBUG
#ifdef DEBUG
#endif
#define LEVEL 5
#if LEVEL > 0
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

13. Waveform Terminology Amplitude Peak-to-peak voltage
SE3910
2/23/2019
Waveform Terminology
Amplitude
Peak-to-peak voltage
Peak voltage (alternative defs)
Period
Frequency (review)
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

14. CS2852
2/23/2019
An Oscilloscope
In tomorrow’s lab, we will read time differences on an oscilloscope…
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

15. Exercise: What is the time delay between the two falling edges?
2/23/2019
Exercise: What is the time delay between the two falling edges?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

16. Exercise: What is the time delay between the two falling edges?
2/23/2019
Exercise: What is the time delay between the two falling edges?
5 ms / Div
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

17. Exercise: What is the rise-time of this signal?
CS2852
2/23/2019
Exercise: What is the rise-time of this signal?
1 Volt/div
1 ms/div
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

18. Sketching Waveforms Sine wave Square wave Sawtooth wave(s) Random wave
CS2852
2/23/2019
Sketching Waveforms
Sine wave
Square wave
Sawtooth wave(s)
Random wave
Effect of changing
Amplitude
Frequency
Phase (time shift)
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

19. [Did not go beyond here in 2-3 class]
SE-2811
Dr. Yoder

20. Technical Goals How does one control the speed of a motor?
SE3910
2/23/2019
Technical Goals
How does one control the speed of a motor?
How does one change the brightness of a light-bulb?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Josiah Yoder

21. Pulse-Width-Modulation … in traffic
CS2852
2/23/2019
Pulse-Width-Modulation … in traffic
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling
Dr. Yoder

22. Pulse-width modulation terminology
Determine the duty cycle (D)
Multiply the duty cycle by the peak voltage (Vp)
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling

23. In-class exercise
How can you control the brightness of an LED, using tools we have discussed so far?
How would you accomplish this if you went into lab right now?
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling

24. Advantages of Pulse-Width Modulation
Click to add text
SE Dr. Josiah Yoder
Slide style: Dr. Hornick
Much Material: Dr. Schilling

25. CS2852
2/23/2019
Muddiest Point
Wait for the slides, or follow this link to answer both questions at once:
SE-2811
Dr.Yoder
Dr. Josiah Yoder

26.
CS2852
2/23/2019
Today, the professor made the course material clear and understandable?
SE-2811
Dr. Josiah Yoder
Dr. Josiah Yoder

27.
CS2852
2/23/2019
What was the muddiest point?
SE-2811
Dr. Josiah Yoder
Dr. Josiah Yoder

28. Slide design: Dr. Mark L. Hornick
References
EB: Derek Malloy, Exploring Beaglebone, Wiley, 2015
SE-2811
Slide design: Dr. Mark L. Hornick
Content: Dr. Hornick
Errors: Dr. Yoder