SAMI MAKERSPACE MAKE: AN ELECTRONICS WORKSHOP. ARDUINO BASICS Credit to: Sparkfun and Linz Craig,...

SAMI

MAKERSPACE

MA

K E : A

N E

L E CT R

ON

I CS W

OR

K S HO

P

ARDUINO

BASICS

Credit to: Sparkfun and Linz Craig, Nick Poole, Prashanta Aryal, Theo Simpson,

Tai Johnson, and Eli Santistevan

THIS PRESENTATION:Part One: Hardware

• Getting around and Arduino

• Getting connected

• The breadboard

• A simple circuit

Part Two: Software

• The integrated development environment

Part Three: Programming

• Inputs and outputs

• Some conventions

• First Program: Blink

• Variables

• Analog versus digital

• Pulse wave modulation

• Second Program: Fade

• Third Program: Button

• Conditional statements

• Serial communication

PART

ONE: T

HE

HARDWARE

AR

DU

I NO

, U

SB

CA

BL E

, L A

PT

OP

, B

RE

AD

BO

AR

D

GETTIN

G AROUND

AN ARDUIN

O

TH

E “

UN

O” M

OD

EL

Analog INPUTS

Digital I\OPWM(3, 5, 6, 9, 10,

11)

PWR IN USB (to Computer)

SCL\SDA(I2C Bus)

POWER 5V / 3.3V /

GND

RESET

LET’

S GET

CONNECTED!

PLUG IN YOUR ARDUINO

BREADBOARDS

RA

PI D

AN

D S

OL D

ER

- F RE

E P

RO

TO

TY

PI N

G!

PROTOTYPING CIRCUITS SOLDERLESS BREADBOARDOne of the most useful tools in an

engineer or Maker’s toolkit. The three most important things:

• A breadboard is easier than soldering• A lot of those little holes are connected, which ones?• Sometimes breadboards break

WHAT’S A BREADBOARD?

SOLDERLESS BREADBOARD

Each row (horiz.) of 5 holes are connected.

Vertical columns – called power bus are connected vertically

A SIM

PLE

CIRCUIT

L I GH

T U

P A

N L

ED

US

I NG

TH

E A

RD

UI N

O

USE THE BREADBOARD AND ARDUINO TO BUILT A SIMPLE CIRCUIT

Use the breadboard to wire up a single LED with a 330 Ohm Resistor (Orange-Orange-Brown).Note: the longer leg on the LED is the positive leg and the shorter leg is the negative

PART

TW

O: THE

SOFTW

ARE

I NT

EG

RA

TE

D D

EV

EL O

PM

EN

T E

NV

I RO

NM

EN

T

THE IN

TEGRAT

ED

DEVELOPM

ENT

ENVIRONMENT

OPEN UP “ARDUINO” APPLICATION

Look for the icon on the desktop of the white clam-shell computers.

You can also download the application for free to your own computers (you may need to also install the proper drivers)

ARDUINO: INTEGRATED DEVELOPMENT ENVIRONMENT (IDE)

Two required functions / methods / routines:

void setup()

{

// runs once

}

void loop()

{

// repeats

}

error & status messages

SETTINGS: TOOLS SERIAL PORT

Your computer communicates to the Arduino microcontroller via a serial port through a USB-Serial adapter.

Check to make sure that the drivers are properly installed.

SETTINGS: TOOLS BOARD

Next, double-check that the proper board is selected under the ToolsBoard menu.

PART

3:

PROGRAMMIN

G

!C

OD

E F

OR

TH

E M

AS

SE

S

CONCEPT: I

NPUTS

VS.

OUTPUTS

CONCEPTS: INPUT VS. OUTPUTReferenced from the perspective of the microcontroller

(electrical board).

Inputs is a signal / information going into the board.

Output is any signal exiting the board.

Almost all systems that use physical computing will have some form of output.What are some examples of Outputs?

CONCEPTS: INPUT VS. OUTPUT

Inputs is a signal / information going into the board.

Output is any signal exiting the board.

Examples: Buttons Switches, Light Sensors, Flex Sensors, Humidity Sensors, Temperature Sensors…

Examples: LEDs, DC motor, servo motor, a piezo buzzer, relay, an RGB LED

YOU DON’T NEED TO SPEAK BINARY!

The Arduino IDE allows you to work in a “high-level programming language.” The code you write is readable to humans (with a little training)

The IDE does the hard work of making your code something that the chip on the Arduino understands:

SUB-ROUTINES/FUNCTIONS/COMMANDS

Arduino uses pre-made sub-routines (small programs) to make your life easier.

Programs like:

• delay()

• if()

• loop()

Most programs need an input (what they are acting on) and give an output (usually a numerical value)

The names of these programs (like most things in Arduino) are case sensitive, so type carefully!

digitalWrite() is not the same as digitalwrite()

Can you guess what these do?

pinMode(pin, INPUT/OUTPUT);

ex: pinMode(13, OUTPUT);

digitalWrite(pin, HIGH/LOW);

ex: digitalWrite(13, HIGH);

delay(time_ms);

ex: delay(2500); // delay of 2.5 sec.

// NOTE: -> commands are CASE-sensitive

digitalWrite()

analogWrite()

digitalRead()

if() statements / Boolean

analogRead()

Serial communication

BIG

6 C

ON

CEP

TS

SOME CONVENTIONS: CURLY BRACKETSWhen you call a sub-routine every thing that happens in the program should be contained in curly brackets:

Everything between the curly brackets {..} is part of the loop function.

SOME CONVENTIONS: SEMICOLONS

Any line of code that isn’t calling a sub-routine, or is a sub-routine that is only one line long should always end with a semicolon (;)

If you forget these, you will get errors when you try to “compile” the code!

SOME CONVENTIONS: COMMENTS

It’s easier to get lost in your own code than you may think.

Leave comments to yourself, especially before you do something “tricky.”

They are not needed to make the program work, but can save you a lot of trouble in the long run.

FIRST

PROGRAM: B

LINK

L ET

’ S M

AK

E A

N L

ED

BL I N

K!

PLAN YOUR ATTACK WITH A FLOWCHART

Initialize

Turn LED ON Wait

Turn LED OFF

Wait

1. PUT IN THE “BARE MINIMUM”

The “setup” function runs once and will lock in any settings you want.

The “loop” function will run for as long as the Arduino has power!

2. INITIALIZE THE LED PIN AS A “OUTPUT”

Use the “pinMode” command. This requires two inputs (or arguments). You must tell it what pin to act on (13 in this case) and whether that pin is an OUTPUT or INPUT (this is case sensitive).

3. TURN ON THE LED FOR ONE SECOND

4. TURN OFF THE LED FOR ONE SECOND

5. REPEAT!

Once the end of the program is reached, it will go to the beginning of loop() and run it again. And again. And again….

SOME EXTRA CHALLENGES…

• Make the light blink with a 200 ms interval.

• Change the blink to mimic a heart beat.

• What’s the fastest blink your eye can detect?

• Add two, three, or four LED’s. (each LED will need its own 330 Ohm resistor).

CONCEPT: V

ARIABLE

S

CONCEPT: VARIABLES

• Declaring variables• Types of variables• Variable scope• Initializing variables• Variable rollover

TYPES OF VARIABLES

8 bits 16 bits 32 bits

byte char

intunsigned int

longunsigned longfloat

DECLARING VARIABLES AND SCOPE OF VARIABLES

Variable Scope

Global Vs.

Function-level

INITIALIZING A VARIABLE: EXAMPLE

Compare this code our early “blink” program.

There is an “int” type variable declared. • An integer (no decimal)

The variable is named “ledPin”

ledPin is initialized to the value “5”

This is a “global” variable since it was declared outside of a function.• All other functions are able to “call”

ledPin and they can change its value

Notice how easy it would be to change the pin on your circuit that has the LED connected to it?

CONCEPT: D

IGITA

L VERSUS

ANALOG

CONCEPTS: ANALOG VS. DIGITAL

Microcontrollers are digital devices – ON or OFF. Also called – discrete.

Analog signals are anything that can be a full range of values. What are some examples?

How can we get 3V from a microcontroller that can only be on (5V) or off (0V)?5 V

0 V

5 V

0 V

CONCEPT: P

WM

PU

L SE

WA

VE

MO

DU

L AT

I ON

CONCEPT: PULSE WAVE MODULATION

To create an analog signal, the digital microcontroller uses a technique called PWM. By varying the duty cycle, we can mimic an “average” analog voltage.

Pulse Width Modulation (PWM)

SECOND PROGRAM: F

ADE

L ET

’ S D

I M T

HA

T L

ED

!

analogWrite(pin, val);

pin – refers to the OUTPUT pin (limited to pins 3, 5, 6, 9, 10, 11.) – denoted by a ~ symbol

val – 8 bit value (0 – 255).

0 => 0V | 255 => 5V

PROJECT #2 – FADINGINTRODUCING A NEW COMMAND…

THIR

D PROGRAM:

BUTTON

CO

NT

RO

L TH

AT

LE

D W

I TH

DI G

I TA

L IN

PU

T!

USE AN EXAMPLE PROGRAM

In Arduino, open up:

File Examples 02.Digital Button

DIGITAL INPUT: BUTTON

to Digital Pin 2

DIGITAL INPUT: BUTTON

This is just like our 1st circuit!

DIGITAL INPUT• Connect digital input to your Arduino using Pins # 0 – 13

(Although pins # 0 & 1 are also used for programming)

• Digital Input needs a pinMode command:

pinMode (pinNumber, INPUT);

Make sure to use ALL CAPS for INPUT

• To get a digital reading:

int buttonState = digitalRead (pinNumber);

• Digital Input values are only HIGH (On) or LOW (Off)

DIGITAL SENSORS• Digital sensors are more straight forward

than Analog

• No matter what the sensor there are only two settings: On and Off

• Signal is always either HIGH (On) or LOW (Off)

• Voltage signal for HIGH will be a little less than 5V on your Uno

• Voltage signal for LOW will be 0V on most systems

USING C

ONDITIO

NAL

STATE

MENTS

I F T

HI S

, T

HE

N T

HA

T!

CONDITIONAL STATEMENTS: IF()

void loop()

{

int buttonState = digitalRead(5);

if(buttonState == LOW)

{ // do something

}

else

{ // do something else

}

}

CONDITIONAL STATEMENTS: IF()

DIG INPUT

BOOLEAN OPERATORS

<Boolean> Description

( ) == ( ) is equal?( ) != ( ) is not equal?( ) > ( ) greater than( ) >= ( ) greater than or equal( ) < ( ) less than( ) <= ( ) less than or equal

SERIAL C

OMMUNICAT

ION

KE

EP

I NG

AN

EY

E O

N Y

OU

R P

RO

GR

AM

…

USING SERIAL COMMUNICATIONMethod used to transfer data between two

devices.

Arduino dedicates Digital I/O pin # 0 to receiving and Digital I/O pin #1 to transmit.

Data passes between the computer and Arduino through the USB cable. Data is transmitted as a string of zeros (‘0’) and ones (‘1’).

SERIAL MONITOR & ANALOGREAD()

Initializes the Serial Communication

9600 baud data rate

prints data to serial bus

SERIAL MONITOR & ANALOGREAD()

Opens up a Serial Terminal Window

EXAMPLE

void loop ( )

{

Serial.print(“Hands on “) ;

Serial.print(“Learning ”) ;

Serial.println(“is Fun!!!”) ;

}

Serial.print adds to the same line. Serial.println adds to the

line, then “returns” (starts a new line).

USING SERIAL COMMUNICATION TO DEBUG AND TROUBLESHOOTLet’s use serial communication to watch what is happening in our “button” program.