Using Android Things to Detect & Exterminate Reptilians

1. Using Android Things
to Detect &
Exterminate
Reptilians

2. Android is
EVERYWHERE (01)
(01)
Reptilians too are everywhere, but they suck.

4. Android Things

5. "If you can build an
app, you can build a
device!"

6. 8-bit Distributed Piano (02)
(02)
https://riggaroo.co.za/android-things-building-distributed-piano/

7. Play Music Like a Scientist

8. Beer Can Music Player (03)
(03)
http://nilhcem.com/android-things/discovering-the-I2C-api-creating-a-capacitive-sensor-driver

9. Notification Cat (04)
(04)
http://nilhcem.com/android-things/bluetooth-low-energy

10. Google Assistant powered Robot
(05)
(05)
http://nilhcem.com/android-things/create-your-google-assistant-robots

11. OK, BUT, WHY?
I mean... I can use an Arduino too

12. Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

13. Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

14. Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

15. Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

16. Compatible boards (06)
• Raspberry Pi 3
• NXP i.MX7D/i.MX6UL
• Intel Edison/Joule (discontinued)
(06)
https://developer.android.com/things/hardware/developer-kits.html

17. Raspberry Pi 3 - NXP i.MX7D

19. SOM (System on module)

20. SOM (System on module)

21. Edison Candle (07)
(07)
https://github.com/androidthings/edison-candle

22. SOMs are pre-certified for
regulator approvals

23. Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

24. Facts
• Humans don't use their brain to its full capacity
• Humans are distracted by media, entertainment, and
politics.
• Borders, country lines lead to endless wars and conflicts

25. Reason?

26. REPTILIANS

27. Reptilian conspiracy theory (08)
(08)
https://www.theatlantic.com/national/archive/2013/04/12-million-americans-believe-lizard-people-run-our-country/
316706/

28. Reptilian
• Altered our DNA so we don't fully use our brain
• Control humans with media / politics
• Have, through the generations, ruled the world

29. Using Android Things
to Detect &
Exterminate
Reptilians

30. Detect

31. TensorFlow (09)
(09)
http://nilhcem.com/android/custom-tensorflow-classifier

32. TensorFlow codelabs
• TensorFlow for Poets (10)
• TensorFlow for Poets 2: Optimize for Mobile (11)
• Android Things Image Classifier (12)
(12)
https://codelabs.developers.google.com/codelabs/androidthings-classifier/index.html
(11)
https://codelabs.developers.google.com/codelabs/tensorflow-for-poets-2/
(10)
https://codelabs.developers.google.com/codelabs/tensorflow-for-poets/

33. Inception v3
• Deep learning model for image recognition
• Transfer learning

34. Gather lots of images

36. Transfer learning
python tensorflow/examples/image_retraining/retrain.py
--bottleneck_dir=~/tf_files/bottlenecks
--how_many_training_steps 4000
--model_dir=~/tf_files/inception
--output_graph=~/tf_files/retrained_graph.pb
--output_labels=~/tf_files/retrained_labels.txt
--image_dir ~/tf_files/reptilians

37. Generated files
• retrained_graph.pb
• retrained_labels.txt

38. Generated files
$ cat retrained_labels.txt
human
reptile
reptilian

39. Mobile model optimizations
python tensorflow/python/tools/optimize_for_inference.py
--input=~/tf_files/retrained_graph.pb
--output=~/tf_files/optimized_graph.pb
--input_names="Mul"
--output_names="final_result"

40. TensorFlow Android Classify
sample (13)
(13)
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/examples/android

41. TensorFlow Inference
val inferenceInterface = TensorFlowInferenceInterface(getAssets(), MODEL_FILE)
val labels = loadLabels() // [ "reptilian", "reptile", "human" ]
fun doRecognize(image: Bitmap) {
val pixels = image.toPixelsArray()
inferenceInterface.feed(INPUT_NODE, pixels, NETWORK_STRUCTURE)
inferenceInterface.run(arrayOf(OUTPUT_NODE))
val outputs = FloatArray(labels.size)
inferenceInterface.fetch(OUTPUT_NODE, outputs)
}

42. TensorFlow Inference
labels = [ "reptilian", "reptile", "human" ]
outputs = [ 0.0098f , 0.0039f , 0.9863f ]

43. Test data

48. AndroidManifest.xml
<application>
<uses-library android:name="com.google.android.things" />
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.IOT_LAUNCHER" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>

49. MainActivity
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
}
}

50. "Hi! I use RelativeLayouts, lol"

51. <?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:src="@drawable/background"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ImageView
android:src="@drawable/reptilian"
android:layout_width="280dp"
android:layout_height="224dp"
android:layout_gravity="bottom|center_horizontal" />
</FrameLayout>

53. "Layouts are dusty"

54. build.gradle
dependencies {
compileOnly 'com.google.android.things:androidthings:0.5.1-devpreview'
}

55. Peripheral I/O APIs

56. Arduino Starter Kit

57. Peripheral I/O APIs (14)
• GPIO
• PWM
• I²C
• I²S
• SPI
• UART
(14)
https://developer.android.com/things/sdk/pio/index.html

59. Blinking LEDs

61. val pioService = PeripheralManagerService()
val ledGpio = pioService.openGpio("BCM4")

62. Magic happens here
ledGpio.value = true
Thread.sleep(1000)
ledGpio.value = false

63. LEDs (15)
(15)
https://fullmoonwanderer.deviantart.com/art/Reptilian-LED-resin-eyes-552330846

64. PeripheralManagerService
fun openGpio(…): Gpio
fun openPwm(…): Pwm
fun openSpiDevice(…): SpiDevice
fun openUartDevice(…): UartDevice
fun openI2cDevice(…): I2cDevice
fun openI2sDevice(…): I2sDevice

65. fun writeBuffer(device: I2cDevice, data: ByteArray) {
device.write(data, data.size)
}

66. Drivers are standard
Android libraries (16)
(17)
(17)
https://github.com/amitshekhariitbhu/awesome-android-things
(16)
https://github.com/androidthings/contrib-drivers

70. build.gradle
compile 'com.google.android.things.contrib:driver-ssd1306:0.4'

71. MainActivity.kt
val display = Ssd1306("I2C1")
display.setPixel(x = 0, y = 0, on = true)

72. val display = Ssd1306("I2C1")
val bmp = BitmapFactory.decodeResource(resources, R.drawable.background)
BitmapHelper.setBmpData(display, 0, 0, bmp, false)
display.show()

74. Android Things
TensorFlow Sample
(18)
(18)
https://github.com/androidthings/sample-tensorflow-imageclassifier

75. Camera

76. Cucumbers (?!?) (19)
(19)
https://cloud.google.com/blog/big-data/2016/08/how-a-japanese-cucumber-farmer-is-using-deep-learning-and-
tensorflow

77. Detect when
someone is
approaching

78. Ultrasonic Sensor (HC-SR04)

79. Ultrasonic Sensor
(HC-SR04)
1. Trigger
2. Echo

80. No Android Things
compatible drivers

81. Arduino to the rescue

82. Arduino to the rescue

83. Arduino to the rescue
void loop() {
distance = getDistanceInCentimeters();
Serial.println(distance);
delay(1000);
}

84. Arduino to the rescue

85. Read data from USB (20)
Hcsr04LiveData(this)
.observe({lifecycle}) { distanceInCm ->
Log.i(TAG, "Distance (cm): $distanceInCm")
}
(20)
https://github.com/Nilhcem/usbfun-androidthings

87. HC-SR04
Hcsr04LiveData(this)
.observe({lifecycle}) { distanceInCm ->
if (distanceInCm < 25) {
takePicture()
}
}

88. git commit -m "Kill reptilian when detected"
if (detected.isReptilian()) {
exterminate()
}

89. Exterminate

90. Option #1: Gun

91. Servo motor

92. Servo motor

93. Servo motor

94. PWM servo
compile 'com.google.android.things.contrib:driver-pwmservo:0.3'

95. Moving the servo
val servo = Servo("PWM0")
servo.setAngleRange(0.0, 180.0)
servo.setPulseDurationRange(1.0, 2.0)
servo.enable = true
servo.angle = servo.minimumAngle

96. Moving the servo
servo.angle = 42.0

98. Option #2:
Flamethrower

100. Flamethrower (21)
(21)
https://www.youtube.com/watch?v=fh6oJZZ27Ro

101. Remote control
• Nearby Connections API
• Bluetooth LE
• Embedded http server
• Whatever you want

102. Option #3: Chainsaw

103. Relay module (22)
(22)
http://nilhcem.com/android-things/google-assistant-smart-home

104. Magic happens here
relay.value = true

108. val colorAnimator = ValueAnimator.ofFloat(0f, 360f).apply {
duration = 8000
repeatCount = ValueAnimator.INFINITE
repeatMode = ValueAnimator.REVERSE
addUpdateListener { animator ->
val leds = getLedsColors(animator.animatedValue)
ledstrip.write(leds)
}
start()
}

109. val path = Path().apply {
moveTo(0f, 0f)
lineTo(0.001f, 400f / 2000f) // 0 secs -> 2.5 fps
lineTo(3f / 23f, 400f / 2000f) // 3 secs -> 2.5 fps
lineTo(6f / 23f, 20f / 2000f) // 6 secs -> 50.0 fps
lineTo(18f / 23f, 20f / 2000f) // 18 secs -> 50.0 fps
lineTo(1f, 1f) // 23 secs -> 0.5 fps
}
val frameDelayAnimator = ValueAnimator.ofInt(0, 2000).apply {
duration = 23000
repeatCount = 0
interpolator = PathInterpolator(path)
start()
}

110. Using Android Things
to Detect &
Exterminate
Reptilians

112. Conclusion

113. Android Things is Fun

114. Easy to get started

115. Reptilians suck (23)
(23)
Unless Reptilians are just an analogy to tell you not to blindly trust media and get you think about reality in a different way

116. Be a maker
Try Android Things, really

117. Using Android Things to
Detect & Exterminate Reptilians
• Twitter:
@Nilhcem
• Slides:
bit.ly/reptilethings