GDGPH Hack Fair Dec 2015 Presentation, The Mind Museum

1. How designing an
Arduino Boot Camp!
inspired me to think about code
(it really did!)

2. Slides prepared for:
GDGPH Hack Fair - December 19, 2015
The Mind Museum Taguig, Manila

3. Hello! I am Mithi!

4. I graduated from BS Electronics and Communication
Engineering in UP Diliman sometime ago...
I am also one of the co-founders
of Nanica.io, a young and small
robotics education start-up.
Hello! I am Mithi!

5. Here are a few things
we do at Nanica.io
(it’s video time, guys!)

6. Our most recent
project is
Arduino Boot Camp:
A Different Approach!

8. A few cool Arduino
projects:

15. Our most recent
project is
Arduino Boot Camp:
A Different Approach!

16. I designed it
with <3 (love)
for beginners and
intermediate Arduino users

17. You can find it at:
http://
ArduinoBootCamp.xyz

18. It’s NOT your usual
Basic Arduino
Workshop >_<

19. How?

20. Well, let me give you
an example.

21. Usually, in beginner
workshops, you are
taught the following:

22. ONE:How to blink an
LED

23. TWO:How to blink an
LED without delay()

24. THREE:How to make
a breathing LED

25. FOUR:How to sweep
a servo back and
forth

26. FIVE:How to light an
LED with a debounced
button

27. This is how the
official Arduino
website teaches you
how to blink an LED...

28. digitalWrite(13, HIGH);
// turn the LED on (HIGH is the voltage level)
delay(1000);
// wait for a second
digitalWrite(13, LOW);
// turn the LED off by making the voltage LOW
delay(1000);
// wait for a second

29. We prefer to do it
like this:

30. led.Toggle();
delay(1000);

31. This is how the
official Arduino
website teaches you
how to blink an LED
without delay()...

32. unsigned long currentMillis = millis();
if(currentMillis - previousMillis >= interval)
{
previousMillis = currentMillis;
if (ledState == LOW)
ledState = HIGH;
else
ledState = LOW;
digitalWrite(ledPin, ledState);
}

33. We prefer to do it
like this:

34. if(metronome.Tick())
led.Toggle();

35. This is how the
official Arduino
website teaches you
how to make a
breathing LED...

36. int fadeValue;
for(fadeValue=0; fadeValue<=255; fadeValue+=5)
{
analogWrite(ledPin, fadeValue);
delay(30);
}
for(fadeValue=255; fadeValue>=0; fadeValue-=5)
{
analogWrite(ledPin, fadeValue);
delay(30);
}

37. We prefer to do it
like this:

38. led.Set(sweeper.Next(metronome.Tick()));

39. if (metronome.Tick())
led.Set(sweeper.Next(1));

40. This is how the
official Arduino
website teaches you
how to sweep a
servo...

41. for (pos = 0; pos <= 180; pos += 1) {
servo.write(pos);
delay(15);
}
for (pos = 180; pos >= 0; pos -= 1) {
servo.write(pos);
delay(15);
}

42. We prefer to do it
like this:

43. if (metronome.Tick()):
servo.write(sweeper.Next(1));

44. servo.write(sweeper.Next(metronome.Tick()));

45. This is how the official
Arduino website
teaches you
how to light an LED with
a debounced button...

46. int reading = digitalRead(buttonPin);
if (reading != lastButtonState) {
lastDebounceTime = millis();
}
if ((millis() - lastDebounceTime) >
debounceDelay) {
if (reading != buttonState) {
buttonState = reading;
if (buttonState == HIGH)
ledState = !ledState;
}
}
digitalWrite(ledPin, ledState);
lastButtonState = reading;

47. We prefer to do it
like this:

48. button.Pressed() ? led.On() : led.Off();

49. Basically, it’s different
because it
emphasizes the
following things
immediately:

50. ONE: CLEAN
READABLE CODE

51. TWO: BASIC OBJECT-
ORIENTED DESIGN

52. THREE: REDUCED
USAGE OF delay()so
you can multi-task
anytime.

53. BUT HOW DO YOU
DO THAT????!?

54. The obvious message
here is how you can
use the power of
OOP design
thinking...

55. ... to abstract
implementation
details...

56. ... so that you can
focus at the things
you want to do.

57. You get the beneficial
side-effects as well:

58. Code that is easy to
understand.

59. Code that is easy to
debug.

60. Code that is multi-
tasking ready.

61. Code that is scalable.
Easily add as many buttons and LEDs as the
Arduino can allow.

62. Code that allows
more complex
behavior.
Add more features and functions without
overwhelming yourself.

63. BUT…
HOW DO YOU DO
THAT EXACTLY
????!?

64. The first step is to
identify the OBVIOUS
objects

65. LED, BUTTON, and
SERVO
(the Arduino already has a built-in servo
class in one of its libraries)

66. DigitalOutput led;
led.New(int pin);
led.On();
led.Off();
led.Toggle();
led.Set(int brightness);

67. Button button;
button.New(pin, debounceTime);
bool state = button.Pressed();

68. The next step is to
identify not so
obvious objects

69. sweeper.New(x1, x2, inc, type);
sweeper.Next(0/1);
// type = BACKANDFORTH/NORMAL
/* if 0, returns current state
** if 1, updates to and return
** next state */

70. metronome.New(milliSeconds)
bool hasTicked= metronome.Tick()

71. You can use sweeper
in myriad
applications…
not just servos and
LEDs...

72. You can use this to
toggle buttons,
play tunes,
do countdowns...

73. and even do away
with long subroutines
because of for-loops.

74. Using metronome instead
of delay(), you get a more
readable code that’s even
multi-tasking ready.

75. You can even sweep
multiple servos….

76. ...blink and sweep
multiple LEDs...

77. ...(simultaneously,
and at different
rates )...

78. ...while catching as
many buttons as you
wish...

79. ...without making
your code a
nightmare.

80. You can even sweep multiple
servos, blink and sweep multiple
LEDs, (simultaneously,
at different rates)
while catching as many buttons as
you wish,
without making your code a
nightmare.

81. Awesome right?!!

82. But wait...

83. ...what about
performance?

84. Only sacrifice readability
for performance if you
have measured that your
code is too slow for its
intended use.

85. Premature
optimization is the
root of all evil.
-Sir Tony Hoare

86. Programs must be written
for people to read, and
only incidentally for
machines to execute.
-Harold Abelson
Structure and Interpretation of Computer Programs

87. Any fool can write code that a
computer can understand. Good
programmers write code that
humans can understand.
-Martin Fowler
Refactoring: Improving the Design of Existing Code

88. If the computer doesn't run it, it's
broken. If people can't read it, it will
be broken. Soon.
-Some Random Guy (or girl?) in
Stack Overflow

89. Correct.
Beautiful.
Fast.
(in that order)
-Elliot Rusty Harold

90. I hope to dispel the
myth that fast code
must be illegible ugly
code...
-Elliot Rusty Harold

91. ...improvement in
beauty can also lead
to improvement in
speed.
-Elliot Rusty Harold

92. One more thing though...

93. No code is God ;)

103. If there’s anything I
hope you take home
from this talk...

104. Two things!

105. First thing...

106. I hope it reminds you to
design your code not only to
work but also to be easily
understood by others…
(and yourself!)

107. Second thing...

108. Second thing…
(and more important thing!)

109. I hope you tell your friends about
http://
ArduinoBootCamp.xyz!
hehehehe :))

110. Thank you
for listening!
:)