Transcript Session 1 Slides - Wolf Den Electronics

Intro to Arduino
Basic Arduino
John Wolf
(WolfDenElectronics.com)
There are 10 types of people. Those that understand binary, and those that do not
understand binary.
Make that 11 types. Those that understand binary, those that don't, and those
who didn't grasp this joke even if they did understand binary.
Objectives – We’ll Learn
 Arduino pedigree
 Arduino Integrated Development
Environment (IDE)
 Serial Monitor interface and other IDE
features-works well with Processing
 Start writing code dJi>gbisea
 Add concepts describing physical
computing as we go – Why explosions occur
More Objectives…
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Pulse Width Modulation (PWM)
Analog signals -> Digital
Driving motors – H-Bridges
How servos work – feedback loops
Pulling it together with Ohm’s Law
Voltage regulators
Power limitation of the USB port
MOST IMPORTANT – Glossary of
terms (learn to use a pencil again)
There are shields for everything you can think of. If not, build one and get rich.
This is why Arduino is
so popular…
www.Arduino.cc or .org How to keep up on Arduinos
Match Arduino to Application
(8-bit computing – yeah!)
Alternatives
Raspberry Pi
Texas Instruments
LaunchPad MSP430
Texas Instruments
BeagleBone Black
Arduino Board of Direction
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“Teach the Youth”
Ivrea, Italy in 2005, Massimo Banzi & David Cuartielles
Open Source Hardware
Atmel Processor (8-bit power)
Coding is accessible (C++, Processing, ModKit and
MiniBloq)
What’s an Arduino?
Digital I/O
header
USB
USB
processor
Atmel AVR
Computer
Power in
(7~12V)
Analog I/O
header
Microcontroller board with all the support electronics built-in on the board. Has
14 digital I/O and 6 analog I/O connections. USB port, power jack, and voltages
for support electronics attached to the board via the headers.
Arduino IDE – resides on laptop
 Where you write your source code
 Compile, link your code and upload to
the board
 Code checker
 Code layout feature
 Organize code and libraries available
 Provides a serial interface via the USB
port to the Arduino board
(IDE => Integrated Development Environment)
App to
interface
to the
Arduino
via USB
console
area
Serial
Monitor
How to get the Arduino S/W
 Go to www.arduino.cc
 Click the “Download” tab
 Now you have a choice:
 If you have a new computer with the latest OS…
go to the turquoise box and click the appropriate
download. I suggest zip files.
 Or… click on “Previous Releases” and download
arduino1.0.6. This is the classic Arduino IDE that
matches the basic set of Arduino boards. The
new software adds-in compatibility with the new
specialty boards and later OS’s.
Where to place the Arduino folder
 Two logical places (although –
anyplace will work, because the IDE
is self contained – not installed into
the OS)
 Just put it in your My Documents folder.
 Better: Put it in your Program Files (86)
folder at C:\Program Files(86)\
 This way, it’s part of your other programs
 Easy to find
How to use the IDE
 Let’s walk through this…
 When you write your first sketch and go
to “save as” to store it, browse to a new
folder you set up in your regular My
Documents directory.
 The IDE will remember this path an store
all your sketches there, plus give you a
library folder to place Third Party
libraries you will want to use.
Integrated Development Environment
 What you do see:
 Area for variables
 The “setup()”
function – void
setup();
 The “loop()”
function – void
loop();
 int main(void); and
Arduino.h are active,
but hidden(C++)
More Arduino.h “methods”
 pinMode – used to tell the compiler whether
a pin is an input or an output
 digitalWrite – whether to write-out a HIGH
or LOW voltage
 digitalRead – read-in the pin voltage for a
HIGH or LOW value
 analogRead – use the A/D converter to read
an analog value (0-5V)
 analogWrite – triggers the PWM feature
Analog to Digital Convertion
+5V
Arduino uses
10bits or 1024
individual levels
from 0 to 1023
Pins A0 to A5
0V
Time(or analogReads)
Pulse Width Modulation
Outputs are always digital, even when representing analog.
For PWM the Arduino pin turns on then off very fast
2 ms
5 Volts
0 Volts
(Arduino PWM base frequency is approx 490 Hz, 980Hz on pins 5, 6)
Let’s Get Our Hands Dirty…
Must be aware of Uno Power Limitations
VIN
Barrel
Connector
Atmel328
GND
USB power called USBVCC.
VIN cuts off USBVCC and applies power directly to +5V
regulator, which also supplies 3.3V regulator.
Barrel connection basically at the VIN point.
Note: VIN polarity not protected like barrel connector.
Regulator can accept 7 to 12V in, 5V out at ~500ma
Basic gear to start fiddling around
Breadboard has
two sets of +5V
rails and Gnds.
Each middle row
is connected
across, but not
down.
9V battery can
supply about
double the
current the
USB port can
Center gutter is
there for and IC
to straddle.
9V Wall-wart usually supply about 1.5A to 2A so are good.
Beef up the +5 Volts for more elaborate projects.
Many projects require current loads or other voltages only and external supply can
adequately handle.
GND
Can use Vin to power the
Arduino
Addition Power Supply
Built from old ATX supply
from a discarded computer
Old ATX
Pwr Box 2.0
Done the same way with better construction technique.
So… you have to learn about
electronics as we go. Next level
is learning how to solder your
projects together – then make
PCBs. All supported by Open
Source developers.
Ohm’s Law
E=IxR
I = 3.8/220
I = 17mA
0 to 5V
input
Pot
Fritzing
CAD layout
220 W
+5V
1.2v
3.8v here
LED
220 W
(190W 20ma)
+5V
GND
GND
Example Sketch (C++)
type
end
int ledPin = 9;
int potPin = A3;
int val = 0;
// LED connected to digital pin 9 (PWM pin)
// potentiometer connected to analog pin 3
// variable to store the value read
void setup()
{
pinMode(ledPin, OUTPUT); // sets the pin as output
pinMode(potPin, INPUT);
// sets the pin as input
}
void loop()
{
val = analogRead(potPin); // read the input pin with ADC 10-bits
analogWrite(ledPin, val / 4);
// analogRead values go from 0 to 1023,
//analogWrite values from 0 to 255
}
Last statement scales the input-read to the output capability of the PWM
Pulse Width Modulation
Outputs are always digital, even when representing analog.
For PWM the Arduino pin turns on then off very fast
2 ms
5 Volts
0 Volts
(Arduino PWM base frequency is approx 490 Hz, 980Hz on pins 5, 6)
Initially HIGH until
button is pushed,
then LOW
Initially LOW until
button is pushed,
then HIGH
Either circuit only draws 0.5 ma
Logic set by path of least resistance
What defines a 1 or 0 ?
 Logic circuits will register a “0” for voltages
from 0 to about 0.8 volts.
 Logic circuits will register a “1” for voltages
from 2 to 5 volts. (some sources quote 3v)
 Notice there is a dead-band where the logic
level is questionable. Stay out of there in
your designs.
 Supplies that can’t hold up the current will
cause voltage sag that can reach a point
where logic gets faulty
Switch bounce caught in the act
0.1ms
Debounce is handled
here in software.
Debounce can also be
handled in hardware.
The 74HLS279 was
specifically designed
to do this task.
Use button to
select different
LED colors.
int
Pot values from the serial interface