1. FrOSCon 2013
Controlling Arduino With PHP

2. About Me
● Thomas Weinert
– @ThomasWeinert
● papaya Software GmbH
– papaya CMS
● PHP, Javascript, XSLT
● XML Fanatic (JSON is BAD)

3. Arduino

4. Arduino Mega

5. Arduino Nano

6. Arduino Nano Breadboard

7. Arduino Nano Breakout

8. Arduino IDE

9. Firmata
● MIDI Based
● Serial Port
– Forks for TCP
● http://firmata.org

10. Non-Blocking I/O
● Event Loop
● Event Emitter
● Promises

11. Event Loop
Listeners
Loop
External
Process
External
Process
File

12. Event Loop
● Timeouts
● Intervals
● Stream Listeners
● Implementations
– StreamSelect
– LibEvent
– MySQLi

13. Browser Example
var e = document.getElementById('output');
var counter = 0;
var interval = window.setInterval(
function() {
e.textContent =
e.textContent +
counter.toString() +
', ';
counter++;
},
1000
);

14. Event Emitter
Object
Event
Callback
Callback
Event
Callback
Event Event
● Attach
● on(), once()
● Trigger
● emit()

15. Event Emitter Example
$stream = new StreamFile('c:/tmp/sample.txt');
$stream->events()->on(
'read-data',
function($data) {
echo $data;
}
);
$stream->events()->on(
'error',
function($error) use ($loop) {
echo $error;
$loop->stop();
}
);

16. Promises
● Asynchronous Condition
● Attach Callbacks
– done()
– fail()
– always()
● Change Status
– reject()
– resolve()

17. jQuery Example
jQuery(
function () {
jQuery
.get('hello-world.xml')
.done(
function (xml) {
$('#output').text(
$('data', xml).text()
);
}
);
}
);

18. Carica Projects
● Carica I/O
– https://bitbucket.org/ThomasWeinert/carica-io
● Carica Firmata
– https://bitbucket.org/ThomasWeinert/carica-firmata
● Carica Chip
– https://bitbucket.org/ThomasWeinert/carica-chip

19. Carica I/O
● Event Loop
– CaricaIoEventLoop
● Event Emitter
– CaricaIoEventEmitter
● Promises
– CaricaIoDeferred
– CaricaIoDeferredPromise

20. Timers
$loop = LoopFactory::get();
$i = 0;
$loop->setInterval(
function () use (&$i) {
echo $i++;
},
1000
);
$loop->setTimeout(
function () use ($loop) {
$loop->stop();
},
10000
);
$loop->run();

21. Asynchronous MySQL
$mysqlOne = new IoDeferredMySQL(
new mysqli('localhost')
);
$mysqlTwo = new IoDeferredMySQL(
new mysqli('localhost')
);
$time = microtime(TRUE);
$debug = function($result) use ($time) {
var_dump(iterator_to_array($result));
var_dump(microtime(TRUE) - $time);
};
$queries = IoDeferred::When(
$mysqlOne("SELECT 'Query 1', SLEEP(5)")
->done($debug),
$mysqlTwo("SELECT 'Query 2', SLEEP(1)")
->done($debug)
);
IoEventLoopFactory::run($queries);

22. Asynchronous MySQL

23. HTTP Server
Why?

24. HTTP Server
● PHP Daemons
– Single process for all pequests
– Share variables

25. Carica HTTP Server
<?php
include(__DIR__.'/../../src/Carica/Io/Loader.php');
CaricaIoLoader::register();
use CaricaIoNetworkHttp;
$route = new CaricaIoNetworkHttpRoute();
$route->startsWith(
'/files', new HttpRouteFile(__DIR__)
);
$server = new CaricaIoNetworkHttpServer($route);
$server->listen(8080);
CaricaIoEventLoopFactory::run();

26. Carica Firmata

27. Carica Firmata Board
<?php
$board = new FirmataBoard(
new IoStreamSerial(
CARICA_FIRMATA_SERIAL_DEVICE,
CARICA_FIRMATA_SERIAL_BAUD
)
);
$board
->activate()
->done(
function () use ($board) { ... }
);
CaricaIoEventLoopFactory::run();

28. Carica Firmata Pins
function () use ($board) {
$buttonPin = 2;
$ledPin = 13;
$board->pins[$buttonPin]->mode = FirmataPIN_STATE_INPUT;
$board->pins[$ledPin]->mode = FirmataPIN_STATE_OUTPUT;
$board->digitalRead(
$buttonPin,
function($value) use ($board, $ledPin) {
$board->pins[$ledPin]->digital =
$value == FirmataDIGITAL_HIGH;
}
);
}

29. Example: Blink
function () use ($board, $loop) {
$led = 9;
$board->pinMode($led, FirmataPIN_STATE_OUTPUT);
$loop->setInterval(
function () use ($board, $led) {
static $ledOn = TRUE;
echo 'LED: '.($ledOn ? 'on' : 'off')."n";
$board->digitalWrite(
$led,
$ledOn
? FirmataDIGITAL_HIGH : FirmataDIGITAL_LOW
);
$ledOn = !$ledOn;
},
1000
);
}

30. RGB Wheel

31. Carica Chip
● Hardware Abstraction
● Device Objects

32. LED
function () use ($board) {
$led = new CaricaChipLed($board, 9);
$led->blink();
}

33. RGB LED
function () use ($board) {
$colors = array('#F00', '#0F0', '#00F');
$led = new CaricaChipLedRgb($board, 10, 11, 9);
$led->setColor('#000');
$index = 0;
$next = function() use ($led, $colors, &$index, &$next) {
if (isset($colors[$index])) {
$color = $colors[$index];
$led->fadeTo($color)->done($next);
}
if (++$index >= count($colors)) {
$index = 0;
}
};
$next();
}

34. Servo
function () use ($board, $loop) {
$positions = array(
0, 45, 90, 180
);
$servo = new CaricaChipServo($board, 7, -180);
$index = 0;
$loop->setInterval(
$next = function () use ($servo, $positions, &$index) {
if (isset($positions[$index])) {
$position = $positions[$index];
$servo->moveTo($position);
echo $position, " Grad , ", $servo->getPosition(), " Gradn";
}
if (++$index >= count($positions)) {
$index = 0;
}
},
2000
);
$next();
}

35. Analog Sensor
function () use ($board) {
$sensor = new CaricaChipSensorAnalog($board, 14);
$sensor->onChange(
function ($sensor) {
echo $sensor, "n";
}
);
}

36. Thank You
● Questions?
● Twitter: @ThomasWeinert
● Blog: http://a-basketful-of-papayas.net