1. Microcomputers

2. Microcomputer Microcontroller
What’s the difference?
Microcomputer Microcontroller

3. Homework 7
What is a microcontroller? What are some common applications of these?
A microcontroller is a simple computer on a single silicon chip that cost only a few dollars.
They are useful in washing machines, toasters, and cars.

4. Microcontrollers in Cars and Trucks?
All modern automobiles contain at least one microcontroller, and can have as many as six or seven.
The engine is controlled by a microcontroller, as are the anti-lock brakes, the cruise control and so on.

5. Interesting…
Any device that has a remote control almost certainly contains a microcontroller: TVs, VCRs and high-end stereo systems all fall into this category.
Digital cameras, cell phones, camcorders, answering machines, laser printers, telephones (the ones with caller ID, 20-number memory, etc.), pagers, and feature-laden refrigerators, dishwashers, washers and dryers.
Basically, any product or device that interacts with its user has a microcontroller buried inside.

6. PIC Microcontroller
We will use the 16F84A microcontroller made by Microchip for the team project. Use the Internet to research these chips.

7. Acronyms IC
RAM
ROM
PROM
EPROM
EEPROM
PIC

8. IC – Integrated Circuits

9. RAM – Random Access Memory

10. ROM – Read Only Memory
ROM cannot be modified (at least not very quickly or easily),

11. ROM – Read Only Memory
ROM cannot be modified (at least not very quickly or easily),

12. PROM – Programmable Read Only Memory
setting of each bit is locked by a fuse

13. PROM
The voltage breaks the connection between the column and row by burning out tiny fuses.
PROMs can only be programmed once.

14. Google “PROM Memory”

15. EPROM – Erasable Programmable Read Only Memory

16. EEPROM – Electronically Erasable Programmable Read Only Memory

18. EEPROM – Electronically Erasable Programmable Read Only Memory

19. PIC – Programmable Integrated Circuits

20. What is RAM? List two types.
RAM = random access memory
Read-and-Write Memory
volatile
Types
Static RAM - on flip-flops
Dynamic RAM - with transistors and capacitors

21. 4. What is ROM? List four types.
ROM = read only memory
nonvolatile (retaining data when powered down)
permanent
Types
mask-programming ROM
written when manufactured
PROM - programmable read-only memory
blow tiny fuses
EPROM - erasable PROM
by UV light
EEPROM - electrically erasable PROM
16F84A

22. EPROM
Erasing an EPROM requires a special tool that emits a certain frequency of ultraviolet (UV) light.

23. EEPROM These are programmed and erased electronically.
These are the kind that we will use for the rovers.

24. List three examples of mass-storage devices.
Hard Disk
Floppy Disk
Digital Tape
CD-ROM

25. Which type of memory is least expensive per using storage
Which type of memory is least expensive per using storage? RAM, ROM, or Mass-Storage?
Mass-Storage

26. Classify each of these as RAM, ROM, Mass-Storage.
Hard Disk
Boot programs are stored here.
CD-ROM
A SIMM or a DIMM for your computer are examples of this.
Floppy Disk
Clothes washer cycle program is stored here.

27. 8. What does A/D and D/A mean?
A/D = Analog to Digital Converters
D/A = Digital to Analog Converters

28. 9. Are multimeters A/D or D/A devices?
Multimeters have A/D converters.
What’s a good example of an D/A converter?

29. The SFA Rover
Team Project

30. A Robot with a Brain
Each vehicle will have a programmable integrated circuit (PIC) that will make decision and control the motors automatically.
This kind of robot control is the same kind of control that is used on Mars robot rovers.

31. The Vehicle Course
6-feet
50-feet

32. The Vehicle Course
6-feet
50-feet
Extra Credit

33. Scoring D = Distance traveled in feet in 10 minutes
(the maximum distance is 50-feet)
R = 15 if the vehicle successfully demonstrates avoiding an obstacle on
the right and 0 if it is not demonstrated
L = 15 if the vehicle successfully demonstrates avoiding an obstacle on
the left and 0 if it is not demonstrated
T = -10 each time the vehicle is touched by a team member during the
course
Grade = T + L + R + D × 70/(50ft)
Bonus: For each extra left or right obstacle avoided, 2 points of extra credit will be earned for each member of the team. A maximum of 20 extra points can be earned in this manner.

34. SFA Rover Circuit Diagram
Left Button
Right Button
9-Volt Battery
PIC Microcontroller
Voltage Regulator
H-Bridge
Left Motor
Right Motor

35. Key Concepts
Note that the parts used in the team project are discussed in your text book.
Chapter 7 - Logic Circuits
Chapter 8 - Microcomputers
Chapter 10 - Diodes (Voltage Regulator)
Chapter 12 - Transistors (H-Bridge)
Chapter 16 - DC Machines (Motors)

36. Key Concepts Other key ideas used in this team project include:
Battery Power Management
Torque
Friction
Gearboxes
We will now design circuits that will be used in lab next week.

39. More Construction
Now use the parts provided to construct a chassis for your vehicle.
If time permits, move you H-Bridge to a portable breadboard and power it using a voltage regulator and 9-Volt battery.
If you are successful, then try to run your vehicle straight down the course.

40. To be continued…
If you did not complete the course, then use some lab time this week to modify your vehicle until it can complete the 50-foot course.
We will integrate the PIC microcontroller and buttons into the circuit later. This will allow the vehicles to avoid obstacles.

41. Beginning the Construction
There should be 3-4 members on each team.
Two team members will now work on together on one Heathkit Digital Experimenter.
In pairs take one motor and connect it between 0 and 5 Volts.
Reverse the wires and notice that the motor rotates in the opposite direction.

42. Beginning the Construction
Turn off the power. Now connect the motors to the H-Bridge chip.
Use two Data Switches as inputs into the H-Bridge that can be used to change the direction of the motors. *
Make notes about your wiring so that you can reconstruct this circuit on a portable breadboard later.

43. Chapter 10
Diodes

44. Semiconductors Germanium Silicon 32 protons 14 protons
Most commonly used

45. Atomic Physics
How many electrons can be in the ground state of an atom?
Answer: 2 (s level)
...in the first excited state?
Answer: 8 (s and p levels)
…in the second excited state?

46. Valence Electrons
Valence electrons are electrons in the outermost shell of the atom that can participate in forming chemical bonds with other atoms.
How many valence electrons does Silicon have?
Answer: 4

47. How many electrons are needed to fill the outermost energy level of Silicon?
Answer: 4
2-D representation of Silicon Crystal
How many valence electrons does Phosphorus (15P) and Aluminum (13Al) have?
Answers: 5 and 3

48. Diodes Conduct electricity in one direction Two terminal devices
anode and cathode
Primarily made of silicon

50. Doping The adding of impurities
n-type crystal
e.g. Silicon doped with Phosphorous
negative charge carriers
electrons
p-type crystal
e.g. Silicon doped with Aluminum
positive charge carriers
vacancy or hole

51. Diodes
Circuit Symbol
p-type
n-type

52. Flapper
Valve
Analogy
Flapper Valve Analogy

53. Diode Characteristics
Forward-Bias Condition
Good Conductor
Reverse-Bias Condition
High Resistance
I versus V Plot
Ideal Diode and Real Diode
“Knee” and Breakdown Voltage
Three Regions

54. Shockley Equation Shockley Equation on Excel
Common LED have a maximum recommended current of 20mA.
What resistor value is needed in series with an LED and a 5-Volt power supply so that the LED does not burn up?
Answer: _______ or ________

55. What does the circuit symbol for an LED look like?

56. Diode Circuits
rec·ti·fi·er Pronunciation: 'rek-t&-"fI(-&)r Function: noun Date: 1611 : one that rectifies; specifically : a device for converting alternating current into direct current
Half-Wave Rectifier
Full-Wave Rectifier
Bridge Rectifier

60. Smoothing Capacitors Ripple Voltage (Vr) DC Component (VDC)
Ripple Factor

61. Concept Test
Is a high or low value for the ripple voltage DV desirable?
Answer: Low
What are three ways to achieve low ripple voltages?
Answers:
Low Current
High Frequency
High Capacitance

62. Zener Diodes
Zener Diodes are intended to operate in the breakdown region.
Manufacturers set the breakdown voltage by modifying the doping.
Zener diodes can make good voltage regulators.
Circuit Symbol
Clarence Zener once visited SFA.

63. What is a Zener diode? How do the circuit symbols for a diode and a Zener diode differ?
Zener diodes are intended to operate in the breakdown region -usually as voltage regulators.
Manufacturers set the breakdown voltage by careful doping.

64. How do you convert AC to DC?
AC Input
Diode
Rectifier
Smoothing
Capacitor
DC Output
Voltage
Regulator
Voltage Regulators remove the ripple.

65. Concept Question
What components to you need to convert a 110-Volt AC signal to a 9-Volt DC signal?
Answers:
Transformer – to step down the voltage
Diodes – to rectify the waveform (make +)
Capacitor – to smooth the rectified waveform
Voltage Regulator – to remove the ripple
Note that the device connected to this 9-Volt power supply acts as a resistor.
For this reason the device is sometimes called the “load” or “load resistance”.

66. Example Questions 10.32, 35 Homework Questions? 10.55, 56, 57, 35

67. What is an ideal diode?
An ideal diode is a perfect conductor with zero voltage drop in the forward bias direction…
…and a perfect insulator in the reverse bias direction.

68. Stop Here

69. What element from the periodic table are diodes made of?
Silicon