Getting Started With Arduino:How to build a Twitter-monitoring
Alertuino
Adrian McEwen - www.mcqn.com
What is Arduino?
Embedded computing platform Open Source Hardware Open Source Software Easy-to-use A way to build the “Internet of
Things”
Adrian McEwen - www.mcqn.com
Common Features
Assortment of Arduinos, but most share the same common features:
16KB flash 1KB RAM 14 digital I/O pins 6 analogue I/O pins
Adrian McEwen - www.mcqn.com
Easy to Learn
Integrated IDE Upload code via USB with a single
click Lots of examples to learn from Active community sharing how they
made their projects
Adrian McEwen - www.mcqn.com
Easy to Extend
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The Anatomy of a Sketch
The code that runs on the Arduino is called a sketch.
Two main parts:– setup()– loop()
This is the Arduino “Hello World” - Blink
Adrian McEwen - www.mcqn.com
The Anatomy of a Sketch: setup()
Runs once, on startup.
Adrian McEwen - www.mcqn.com
The Anatomy of a Sketch: loop()
Runs continually, after startup.
Adrian McEwen - www.mcqn.com
Seeing Blink in Action
1. Load Blink example in the IDE: File -> Sketchbook -> Examples -> Digital -> Blink
2. Click the upload button: 3. Watch the LED blink**on boards other than the Diecimila and Duemilanove you might
need to connect an LED between digital pin 13 and GND
Adrian McEwen - www.mcqn.com
Now the real fun starts…
Adrian McEwen - www.mcqn.com
Some (Very) Basic Electronic Concepts
You can think of electronics in a similar way to how you’d think of plumbing
Voltage [V]: a bit like water pressure Current [I]: a bit like the amount of
water flowing through something Resistance [R]: a bit like the (inverse
of the) diameter of a water pipe
Adrian McEwen - www.mcqn.com
Ohm’s Law
The only equation you’ll need to begin tinkering
Voltage = Current x Resistance Current = Voltage / Resistance Resistance = Voltage / CurrentLearn more as you want to do more…
Adrian McEwen - www.mcqn.com
Tinkering With Toys
Hacking a toy ray gun to notify me when someone twitters about #barcampliverpool
Adrian McEwen - www.mcqn.com
Take 1 Cheap Toy Ray Gun
Battery-operated electronic toys are ideal
Takes 3 AAA batteries, so near enough to the Arduino’s 5V
Adrian McEwen - www.mcqn.com
Open It Up
Find the connections to bypass the switch and turn the toy on
Use 5V and GND connections on Arduino with some wires to test where the connections should go
Adrian McEwen - www.mcqn.com
Make New Connections
Solder the connections ideally
But you could cut the wires and connect new ones with connecting block
Adrian McEwen - www.mcqn.com
Parts We’ll Use
Resistor – 1K ohm (brown-black-red)
Adrian McEwen - www.mcqn.com
Parts We’ll Use
Transistor – basically an electronically operated switch(we’re using a 2N2222)
Adrian McEwen - www.mcqn.com
Parts We’ll Use
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Breadboard – easy, solderless prototyping board
Transistors in (a Bit) More Detail
Adrian McEwen - www.mcqn.com
Wire emitter to –ve/GND side of circuit Wire collector to +ve side of circuit Current will flow from collector to emitter
when a voltage is applied to base
Our Circuit
Adrian McEwen - www.mcqn.com
Software
Computer will fetch the data from Twitter for us
Then send the number of alerts over serial to the Arduino
The Arduino will listen for the number of alerts over serial
Then turn on the toy for 2 seconds for each alert
Adrian McEwen - www.mcqn.com
Alertuino Software: setup()
Runs once, on startup.
Adrian McEwen - www.mcqn.com
Alertuino Software: loop()
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Lets Try It
1. Upload the Alertuino sketch2. Start the serial monitor 3. Send it a command4. Enjoy**fingers crossed ;-)
Adrian McEwen - www.mcqn.com
Find out more
My Blog: http://www.mcqn.net/mcfilter/
Or email [email protected] a beginners kit:
http://tinker.it/ukstore/product_info.php?cPath=29&products_id=51
Download the software: http://www.arduino.cc/
Learn more: http://arduino.cc/en/Tutorial/HomePage
Adrian McEwen - www.mcqn.com