Endless fun with Arduino and Eventmachine

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Bodo Tasche@bitboxer

Endless fun with Arduino and Eventmachine

Eventmachine

!!!

!!

Arduino?

?

? ?!

Source: Wikipedia

Two Parts

1. Hardware

Arduino Uno

Microcontroller

Operating Voltage

Input Voltage (recommended)

Input Voltage (limits)

Digital I/O Pins

Analog Input Pins

DC Current per I/O Pin

DC Current for 3.3V Pin

Flash Memory

SRAM

EEPROM

Clock Speed

ATmega328

5V

7-12V

6-20V

14

6

40 mA

50 mA

32 KB

2 KB

1 KB

16 MHz

2. So!ware

http://arduino.cc

Christopher Pike, isthis you?

const int PIN_LED = 13;

void setup() { pinMode(PIN_LED, OUTPUT);}

void loop() { digitalWrite(PIN_LED, HIGH); delay(500); digitalWrite(PIN_LED, LOW); delay(500);}

Have you brought any fruits or vegetables to the mars?

Two weeks.

const int BAUD_RATE = 9600;

void setup() { Serial.begin(BAUD_RATE);}

void loop() { Serial.println(“Hello, world!”); delay(1000);}

Well, well, Private Joker, I don't believe I heard you correctly!

http://arduino.cc/en/Tutorial/SwitchCase2

void setup() { Serial.begin(9600); for (int thisPin = 2; thisPin < 7; thisPin++) { pinMode(thisPin, OUTPUT); }}

void loop() { if (Serial.available() > 0) { int inByte = Serial.read(); switch (inByte) { case 'a': digitalWrite(2, HIGH); break; case 'b': digitalWrite(3, HIGH); break; case 'c': digitalWrite(4, HIGH); break; case 'd': digitalWrite(5, HIGH); break; case 'e': digitalWrite(6, HIGH); break; default: for (int thisPin = 2; thisPin < 7; thisPin++) { digitalWrite(thisPin, LOW); } } }}

Eventmachine+

Arduino

It‘s all about the volume!

Source: Wikipedia

const int POT_PIN = 2;

int val;

void setup() { Serial.begin(9600);}

void loop() { int newVal = map(analogRead(POT_PIN), 0, 1023, 7, 0);

if (val != newVal) { val = newVal; Serial.println(val); }

}

Source: Wikipedia

require 'serialport'

sp = SerialPort.new('/dev/tty.your-usb-device', 9600, 8, 1, 0)

loop do line = sp.gets if line puts "New volume : #{line}" `osascript -e "set volume #{line}"` endend

sp.close

Talk to the hand

require 'rubygems'require 'serialport'require 'eventmachine'

$sp = SerialPort.new('/dev/tty.your-usb-device', 9600, 8, 1, 0)

class DataBuffer < EM::Protocols::LineAndTextProtocol

def initialize puts "hello stranger..." end

def receive_data(data) EventMachine::defer do $sp.puts data.strip send_data($sp.gets) end end

end

EventMachine::run do EventMachine::start_server "127.0.0.1", 8081, DataBufferend

sp.close

EventMachine::defer

Don’t write a deferred operation that will block forever [...] We

might put in a timer to detect this

$eventmachine_library = :pure_ruby # need to force pure rubyrequire 'eventmachine'gem_original_require 'serialport'require 'smsrelay/gsmpdu'

module EventMachine class EvmaSerialPort < StreamObject def self.open(dev, baud, databits, stopbits, parity) io = SerialPort.new(dev, baud, databits, stopbits, parity) return(EvmaSerialPort.new(io)) end

def initialize(io) super end

## # Monkeypatched version of EventMachine::StreamObject#eventable_read so # that EOFErrors from the SerialPort object (which the ruby-serialport # library uses to signal the fact that there is no more data available # for reading) do not cause the connection to unbind. def eventable_read @last_activity = Reactor.instance.current_loop_time begin if io.respond_to?(:read_nonblock) 10.times { data = io.read_nonblock(4096) EventMachine::event_callback uuid, ConnectionData, data } else data = io.sysread(4096) EventMachine::event_callback uuid, ConnectionData, data end rescue Errno::EAGAIN, Errno::EWOULDBLOCK, EOFError # no-op rescue Errno::ECONNRESET, Errno::ECONNREFUSED @close_scheduled = true EventMachine::event_callback uuid, ConnectionUnbound, nil end end end

class << self def connect_serial(dev, baud, databits, stopbits, parity) EvmaSerialPort.open(dev, baud, databits, stopbits, parity).uuid end end

def EventMachine::open_serial(dev, baud, databits, stopbits, parity, handler=nil) klass = if (handler and handler.is_a?(Class)) handler else Class.new( Connection ) {handler and include handler} end s = connect_serial(dev, baud, databits, stopbits, parity) c = klass.new s @conns[s] = c block_given? and yield c c end

class Connection # This seems to be necessary with EventMachine 0.12.x def associate_callback_target(sig) return(nil) end endend

https://github.com/eventmachine/eventmachine/wiki/Code-Snippets

If you build it...

http://blog.last.fm/2008/08/01/quality-control

Last.fm

http://urbanhonking.com/ideasfordozens/2010/05/19/the_github_stoplight/

github

by-nc-nd by seanb.murphy http://www.flickr.com/photos/greenstorm/2425378283

Weather station

Infrared Sender/Receiver

Improve your „green thumb“

CAN-bus

Connect your Arduino with your car

Gong-o-bot

Gong-o-bot

fritzing.org/projects/

fritzing.org/shop/starter-kit/

Find a hackerspace!

delicious.com/bitboxer/arduino

Don‘t be evil

Source: Wikipedia

Be good!

Source: Wikipedia

"ank you!