1. Microcontrollers, Microcomputers, and Microprocessors
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Microcontrollers, Microcomputers, and Microprocessors
Digital Electronics
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Copyright 2009

2. ATmega328 Microcontroller Processor Memory
General Safety
Microcontroller, Microcomputer, or Microprocessor? What is the difference?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
A microcontroller is a small, low cost computer on a single integrated circuit.
ATmega328 Microcontroller
Processor
Memory
Programmable Input/Output(I/O)
Arduino Uno Microcontroller Board
SparkFun Electronics, . Arduino Uno - R
Photograph. Wikipedia Commons Web. 7 Jan 2014.
Microcontrollers are used to perform one dedicated task. One specific program. They are usually embedded in products.
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3. input/output (I/O) facilities
General Safety
Microcontroller, Microcomputer, or Microprocessor? What is the difference?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit.
It includes:
a microprocessor
memory
input/output (I/O) facilities
Commodore 64 Microcomputer
Evan-Amos, . Commodore-64-Computer
Photograph. Wikipedia Commons Web. 7 Jan <
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4. Why is it called a “micro” computer?
General Safety
Microcontroller, Microcomputer, or Microprocessor? What is the difference?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Why is it called a “micro” computer?
Early computers such as ENIAC filled entire rooms.
A “micro”computer by comparison with a keyboard, monitor, and mouse are commonly referred to as a personal computer today.
The prefix “micro” is not commonly used in describing computers anymore.
U.S. Army Photo, . ENIAC Photograph. Wikipedia Commons Web. 7 Jan 2014.
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5. Microcontroller, Computer, or Processor? What is the difference?
General Safety
Microcontroller, Computer, or Processor? What is the difference?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Application Processors
As the use of smart phones and mobile devices has expanded, a new type of processor has been defined.
Intel® Quark SoC X1000 Application Processor
Today, microprocessors in computers are often just referred to as processors. All computers today have a processor as the CPU. Microprocessors designed for use in mobile applications are called application processors.
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6. Microprocessors don’t have RAM, ROM, and other peripheral on the chip.
General Safety
Microcontroller, Microcomputer, or Microprocessor? What is the difference?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
A microprocessor is an IC which has only the Central Processing Unit inside them. They only have processing powers.
Microprocessors don’t have RAM, ROM, and other peripheral on the chip.
A system designer has to add them externally to make them functional. 
Once again, the prefix “micro” is increasingly left today in favor of just processor.
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7. What is a Microcontroller?
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Microcontrollers are used to control many everyday products like garage door openers, traffic lights, home thermostats, and robots. Embedded controllers are everywhere.
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Copyright 2009

8. What are the Parts of a Microcontroller?
General Safety
What are the Parts of a Microcontroller?
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Microcontrollers contain:
A Central Processing Unit (CPU)
Some form of memory (MEMORY)
Programmable Input / Output (I/O)
ATmega328 Microcontroller
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9. What are the Parts of the Arduino Microcontroller Board?
General Safety
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The Arduino Microcontroller Board Specifications:
(14) Digital I/O Pins: (6) are PWM Specific
(6) Analog I/O Pins
Power: USB or external. If using power supply with mm center-positive plug, recommend range 7V-12V.
USB Connection: Type B
5V or 3.3V option
Digital / PWM
Analog
USB
Power
Vext
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10. Programming a Microcontroller
General Safety
Programming a Microcontroller
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Programming languages have their own grammar called syntax.
Programs written with the Ardiuno software are called Sketches.
A Sketch (program written with Arduino) will contain:
Variables
Functions
Setup()
Loop()
Structures
Comments
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Copyright 2009

11. Programming a Microcontroller
General Safety
Programming a Microcontroller
Digital Electronics TM
1.1 Foundations and The Board Game Counter
The Arduino software consists of an Integrated development environment (IDE) and the core libraries.
The core libraries are written in C and C++ and compiled using avr-gcc and AVR Libc.
The Arduino software language you program in is very similar to C++ because it is derived from C/C++.
These connections to C and C++, two languages that professional programmers are usually familiar with, make it a good platform for programmers who want to start tinkering.
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Copyright 2009

12. General Safety
Example: Blink
Digital Electronics TM
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This sketch (program) will continue to turn on LED on for 1 second and off for 1 second.
The sketch (program) includes :
setup() function - Initializes variables, pin modes, start using libraries, etc.
loop() function - loops code consecutively.
// Comments - Detailed descriptions not executed.
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13. Example: Blink
General Safety
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void - The void keyword is used only in function declarations.
It indicates that the function is expected to return no information to the function from which it was called.
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14. Example: Blink Syntax: { } Curly Braces
General Safety
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Syntax: { } Curly Braces
(also referred to as just "braces" or as "curly brackets")
Curly Braces are a major part of the C programming language.
Balanced Braces - An opening curly brace "{" must always be followed by a closing curly brace "}".
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Copyright 2009

15. General Safety
Example: Blink
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Curly Braces – Beginning programmers, and programmers coming to C from the BASIC language often find using braces confusing or daunting.
The same curly braces in C replace: the RETURN statement in a subroutine (function), the ENDIF statement in a conditional and the NEXT statement in a FOR loop in the BASIC language.
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Copyright 2009

16. Example: Blink Syntax: The main uses of { } Curly Braces Functions
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Syntax: The main uses of { } Curly Braces
Functions
void myfunction(datatype argument){
statements(s) }
Loops
while (boolean expression) {
statement(s) do
} while (boolean expression);
for (initialisation; termination condition; incrementing expr)
Conditional statements
if (boolean expression) {
statement(s) }
else if (boolean expression)
else
It is good programming practice to type the closing brace immediately after typing the opening brace when inserting a construct which requires curly braces. Then insert some carriage returns between your braces and begin inserting statements.
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Copyright 2009

17. Example: Blink /* Blink
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter /*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain. */
// Pin 13 has an LED connected on most Arduino boards.
// give the variable “integer” the name “led”:
int led = 13;
// the setup routine runs once to declare function when you press reset:
void setup() {
// initialize the digital pin “pinMode” you defined as “led” as an output.
pinMode(led, OUTPUT); }
// the void loop routine runs over and over again forever:
void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(led, LOW); // turn the LED off by making the voltage LOW
Project Lead The Way, Inc.
Copyright 2009

18. General Safety
Example: Blink
Digital Electronics TM
1.1 Foundations and The Board Game Counter /*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain. */
// Pin 13 has an LED connected on most Arduino boards.
// give the variable “integer” the name “led”:
int led = 13;
A variable is a place for storing a piece of data. It has a type, a name, and a value.
For example, the Blink sketch declares a variable with: the type “integer” int, name led, and an initial value = 13;
It's being used to indicate which Arduino pin the LED is connected to. Every time the name led appears in the code, its value will be retrieved.
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Copyright 2009

19. Example: Blink Variable Data Types Include: void boolean char
General Safety
Example: Blink
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Variable Data Types Include:
void
boolean
char
unsigned char
byte
int
unsigned int
word
unsigned long
short
float
double
string - char array
String - object
Array
long
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Copyright 2009

20. Example: Blink
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter /*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain. */
// Pin 13 has an LED connected on most Arduino boards.
// give the variable “integer” the name “led”:
int led = 13;
// the setup routine runs once to declare function when you press reset:
void setup() {
// initialize the digital pin “pinMode” you defined as “led” as an output.
pinMode(led, OUTPUT); }
A function (also known as a sub-routine) is a named piece of code that can be used from elsewhere in the code.
The setup() function in this example sets the variable led as an OUTPUT.
Project Lead The Way, Inc.
Copyright 2009

21. Example: Blink
General Safety
Digital Electronics TM
1.1 Foundations and The Board Game Counter /*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain. */
// Pin 13 has an LED connected on most Arduino boards.
The loop() function loops consecutively, allowing your program to change and respond. Use it to actively control the Arduino board.
// the void loop routine runs over and over again forever:
void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(led, LOW); // turn the LED off by making the voltage LOW }
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Copyright 2009

22. Dual-axis Accelerometer
General Safety
Your Turn
Digital Electronics TM
1.1 Foundations and The Board Game Counter
Open Source Community
Arduino Software is free. You can install it at home if you would like to continue work on your DE projects and/or create new projects of your own.
For the newest version of Aurdino IDE visit their website.
In the next activities, you will program a microcontroller to integrate new types of sensors and input devices.
Memsic 2125
Dual-axis Accelerometer
PIR Sensor
(Passive Infra-Red)
2-Axis Joystick
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Copyright 2009