1. Introduction to Arduino Microcontrollers
Jeff McRaven

2. Overview Background What To Get (Hardware and Software) Arduino C
Microcontroller defined/Why Arduino's?
Types of Arduino microcontrollers
What To Get (Hardware and Software)
Arduino C
Electronic Circuits
Projects
Blinking light(s)
Reading inputs (variable resistors)

3. Microcontrollers – One Definition
Programmers work in the virtual world.
Machinery works in the physical world.
How does one connect the virtual world to the physical world?
Enter the microcontroller.
A microcontroller is basically a small-scale computer with generalized (and programmable) inputs and outputs.
The inputs and outputs can be manipulated by and can manipulate the physical world.

4. Arduino – Official Definition
Taken from the official web site (arduino.cc):
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

5. Why Arduino?
For whatever reason, Arduino microcontrollers have become the de facto standard.
Make Magazine features many projects using Arduino microcontrollers.
Strives for the balance between ease of use and usefulness.
Programming languages seen as major obstacle.
Arduino C is a greatly simplified version of C++.
Inexpensive ($35 retail).

6. Arduino Types Many different versions Leonardo Due Micro LilyPad
Number of input/output channels
Form factor
Processor
Leonardo
Due
Micro
LilyPad
Esplora
Uno

7. Leonardo Compared to the Uno, a slight upgrade.
Built in USB compatibility
Bugs?
Presents to PC as a mouse or keyboard

8. Due Much faster processor, many more pins Operates on 3.3 volts
Similar to the Mega

9. Micro When size matters: Micro, Nano, Mini
Includes all functionality of the Leonardo
Easily usable on a breadboard

10. LilyPad
LilyPad is popular for clothing-based projects.

11. Esplora Game controller
Includes joystick, four buttons, linear potentiometer (slider), microphone, light sensor, temperature sensor, three-axis accelerometer.
Not the standard set of IO pins.

12. Mega Compared to the Uno, the Mega: Many more communication pins
More memory
Some interface hardware doesn't work

13. Arduino Uno Close Up The pins are in three groups: Invented in 2010
14 digital pins
6 analog pins
power

14. Where to Start Get an Arduino (starter kit) Download the compiler
Connect the controller
Configure the compiler
Connect the circuit
Write the program
Get frustrated/Debug/Get it to work
Get excited and immediately start next project
(sleep is for wimps)

15. Arduino Starter Kits Start with a combo pack (starter kit)
Includes a microcontroller, wire, LED's, sensors, etc.
adafruit.com/products/68 ($65)
($99.95)
Radio Shack
Make Ultimate Microcontroller Pack w/ Arduino Kit ($119.99)
($150)

16. What to Get – My Recommendation
Required:
Arduino (such as Uno)
USB A-B (printer) cable
Breadboard
Hookup wire
LED's
Resistors
Sensors
Switches
Good Idea:
Capacitors
Transistors
DC motor/servo
Relay
Advanced:
Soldering iron & solder
Heat shrink tubing
9V battery adapter
Bench power supply

17. Arduino Compiler Download current compiler from:
arduino.cc/en/Main/software
Arrogantly refers to itself as an IDE (Ha!).
Run the software installer.
Written in Java, it is fairly slow.
Visit playground.arduino.cc/Main/ DevelopmentTools for alternatives to the base arduino IDE

18. Configuring the Arduino Compiler
Defaults to COM1, will probably need to change the COM port setting (my work PC uses 7).
Appears in Device Manager (Win7) under Ports as a Comm port.

19. Arduino Program Development
Based on C++ without 80% of the instructions.
A handful of new commands.
Programs are called 'sketches'.
Sketches need two functions:
void setup( )
void loop( )
setup( ) runs first and once.
loop( ) runs over and over, until power is lost or a new sketch is loaded.

20. Arduino C
Arduino sketches are centered around the pins on an Arduino board.
Arduino sketches always loop.
void loop( ) {} is equivalent to while(1) { }
The pins can be thought of as global variables.

21. Arduino C Specific Functions
pinMode(pin, mode)
Designates the specified pin for input or output
digitalWrite(pin, value)
Sends a voltage level to the designated pin
digitalRead(pin)
Reads the current voltage level from the designated pin
analog versions of above
analogRead's range is 0 to 1023
serial commands
print, println, write

22. Compiler Features
Numerous sample sketches are included in the compiler
Located under File, Examples
Once a sketch is written, it is uploaded by clicking on File, Upload, or by pressing <Ctrl> U

23. Arduino C is Derived from C++
These programs blink an LED on pin 13
avr-libc
#include <avr/io.h>
#include <util/delay.h>
int main(void) {
while (1) {
PORTB = 0x20;
_delay_ms(1000);
PORTB = 0x00; }
return 1;
Arduino C
void setup( ) {
pinMode(13, OUTPUT); }
void loop( ) {
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);

24. Basic Electric Circuit
Every circuit (electric or electronic) must have at least a power source and a load.
The simplest circuit is a light.
Plug in the light, and it lights up.
Unplug it, the light goes out.
Electricity flows from the power source, through the load (the light) and then back to the power source.

25. Basic LED Circuit
Connect the positive (+) lead of a power source to the long leg of an LED.
Connect other leg of the LED to a resistor.
High resistance means a darker light.
Low resistance means brighter light.
No resistance means a burned out LED.
Connect other leg of the resistor to the negative lead of the power source.

26. Let the Good Times Roll! At this point we have: Let's write some code!
Purchased a starter kit, including the Arduino
Connected and configured the Arduino
Connected a simple LED circuit
Let's write some code!

27. Blink Sketch void setup( ) { pinMode(13, OUTPUT); } void loop( ) {
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
Connected to one end of the circuit
Connected to other end of the circuit
GND to ground and 13 to power
330 ohm ground and LED
LED to 330 ohm and power

28. 4 LED Blink Sketch void setup( ) { pinMode(1, OUTPUT);}
void loop( ) {
digitalWrite(1, HIGH);
delay (200);
digitalWrite(1, LOW);
digitalWrite(3, HIGH);
digitalWrite(3, LOW);
digitalWrite(5, HIGH);
digitalWrite(5, LOW);
digitalWrite(7, HIGH);
digitalWrite(7, LOW); }

29. So What? Great. Blinking lights. Not impressed.
Only covered output thus far.
Can use analog inputs to detect a physical phenomena.

30. Inputs
Digital inputs will come to the Arduino as either on or off (HIGH or LOW, respectively).
HIGH is 5VDC.
LOW is 0VDC.
Analog inputs will come to the Arduino as a range of numbers, based upon the electrical characteristics of the circuit.
0 to 1023
.0049 V per digit (4.9 mV)
Read time is 100 microseconds (10,000 a second)

31. Analog Input
A potentiometer (variable resistor) is connected to analog pin 0 to an Arduino.
Values presented to pin 0 will vary depending upon the resistance of the potentiometer.
void setup() {
Serial.begin(9600); }
void loop() {
Serial.println(analogRead(0));

32. Analog Input-Application
The variable resistor can be replaced with a sensor.
For example, a photo resistor.
Depending upon the light level at the photo resistor:
Turn on a light
Increase or decrease the brightness of an LED (or an LED array)
Most sensors are simply variable resistors, but vary their resistance based on some physical characteristic.
void setup() {
pinMode(9, OUTPUT); }
void loop()
int lightLevel = analogRead(0);
lightLevel = map(lightLevel, 0, 900, 0, 255);
lightLevel = constrain(lightLevel, 0, 255);
analogWrite(9, lightLevel);

33. Sensors Sensors can be both binary or a range.
Usually, sensors that measure a range of values vary their resistance to reflect their detection.
Arduinos can only sense voltages, not resistances.
Sensors that only vary their resistances require a circuit called a voltage divider to provide the Arduino a voltage.

34. Common Sensors Dials on a radio are simply potentiometers Temperature
Light
Angle
Switches
did the user throw a switch or push a button?
Accelerometer (measures motion and tilt)
Infrared sensor & light
Hall effect sensor and magnet
Ball tilt sensor (for measuring orientation)
Force

35. “Competitors”to the Arduino
PIC controller
Microcontroller programmed with C or assembler
Alternatives to the Arduino line
Pinguino – PIC controller
MSP430 – Texas Instruments; $4.30
Others: customs, Teensy, etc.
Netduino
Computers
Raspberry Pi
BeagleBones – TI; has computer and controller

36. Netduino
Microcontroller and development tools created by Microsoft to work with the .NET Micro Framework.
VASTLY better development environment.
visualmicro.com
Other alternatives
Differences
Pins on a Netduino are 3.3V (not 5).
Netduinos have a much faster processor.
60K of RAM (versus an Uno's 2K).
Largely compatible with the Arduino, but it is not a drop-in replacement (can fry it).

37. Raspberry Pi Low end computer, not a controller Uses Debian Linux
Arch Linux ARM, Fedora, FreeBSD, Slackware…
Programmed with Python
BBC BASIC, C, Perl
As it is a computer and not a controller, its role in these projects is different.
Hierarchy: computers control controllers, controllers control hardware.

38. Shields
Shields are circuit boards that plug into the top of an Arduino.
They extend the capabilities of an Arduino.
Examples:
Ethernet
GPS
Motor
Prototype
shieldlist.org

39. Conclusion
The Arduino microcontroller is a low cost way to enter into the hobby of robotics.
The Arduino has two plusses over any other:
The user community
Extensive online library of code and projects
Viewed as the "base" system, upon which all other microcontrollers are built. Compatibility.
So get a kit, and start ushering in the inevitable takeover of our robotic overlords!

40. Introduction to Arduino Microcontrollers
Jeff McRaven