1.
Using Android Things
to Detect &
Exterminate
Reptilians

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

3.
Android Things

4.
"If you can build an
app, you can build a
device!"

5.
8-bit Distributed Piano (02)
(02)
https://riggaroo.co.za/android-things-building-distributed-piano/

6.
Play Music Like a Scientist

7.
Beer Can Music Player (03)
(03)
http://nilhcem.com/android-things/discovering-the-I2C-api-creating-a-capacitive-sensor-driver

8.
Notification Cat (04)
(04)
http://nilhcem.com/android-things/bluetooth-low-energy

9.
Google Assistant powered Robot
(05)
(05)
http://nilhcem.com/android-things/create-your-google-assistant-robots

10.
OK, BUT, WHY?
I mean... I can use an Arduino too

11.
Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

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.
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

16.
Raspberry Pi 3 - NXP i.MX7D

17.
SOM (System on module)

18.
SOM (System on module)

19.
Edison Candle (07)
(07)
https://github.com/androidthings/edison-candle

20.
SOMs are pre-certified for
regulator approvals

21.
Perfect for
• Doing some computation locally
• Using Google Services
• A secure platform
• Prototype and production

22.
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

23.
Reason?

24.
REPTILIANS

25.
Reptilian conspiracy theory (08)
(08)
https://www.theatlantic.com/national/archive/2013/04/12-million-americans-believe-lizard-people-run-our-country/
316706/

26.
Reptilian
• Altered our DNA so we don't fully use our brain
• Control humans with media / politics
• Have, through the generations, ruled the world

27.
Using Android Things
to Detect &
Exterminate
Reptilians

28.
Detect

29.
TensorFlow (09)
(09)
http://nilhcem.com/android/custom-tensorflow-classifier

30.
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/

31.
Inception v3
• Deep learning model for image recognition
• Transfer learning

32.
Gather lots of images

33.
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

34.
Generated files
• retrained_graph.pb
• retrained_labels.txt

35.
Generated files
$ cat retrained_labels.txt
human
reptile
reptilian

36.
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"

37.
TensorFlow Android Classify
sample (13)
(13)
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/examples/android

38.
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)
}

39.
TensorFlow Inference
labels = [ "reptilian", "reptile", "human" ]
outputs = [ 0.0098f , 0.0039f , 0.9863f ]

40.
Test data

41.
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>

42.
MainActivity
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
}
}

43.
"Hi! I use RelativeLayouts, lol"

44.
<?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>

45.
"Layouts are dusty"

46.
build.gradle
dependencies {
compileOnly 'com.google.android.things:androidthings:0.5.1-devpreview'
}

47.
Peripheral I/O APIs

48.
Arduino Starter Kit

49.
Peripheral I/O APIs (14)
• GPIO
• PWM
• I²C
• I²S
• SPI
• UART
(14)
https://developer.android.com/things/sdk/pio/index.html

50.
Blinking LEDs

51.
val pioService = PeripheralManagerService()
val ledGpio = pioService.openGpio("BCM4")

52.
Magic happens here
ledGpio.value = true
Thread.sleep(1000)
ledGpio.value = false

53.
LEDs (15)
(15)
https://fullmoonwanderer.deviantart.com/art/Reptilian-LED-resin-eyes-552330846

54.
PeripheralManagerService
fun openGpio(…): Gpio
fun openPwm(…): Pwm
fun openSpiDevice(…): SpiDevice
fun openUartDevice(…): UartDevice
fun openI2cDevice(…): I2cDevice
fun openI2sDevice(…): I2sDevice

55.
fun writeBuffer(device: I2cDevice, data: ByteArray) {
device.write(data, data.size)
}

56.
Drivers are standard
Android libraries (16)
(17)
(17)
https://github.com/amitshekhariitbhu/awesome-android-things
(16)
https://github.com/androidthings/contrib-drivers

57.
build.gradle
compile 'com.google.android.things.contrib:driver-ssd1306:0.4'

58.
MainActivity.kt
val display = Ssd1306("I2C1")
display.setPixel(x = 0, y = 0, on = true)

59.
val display = Ssd1306("I2C1")
val bmp = BitmapFactory.decodeResource(resources, R.drawable.background)
BitmapHelper.setBmpData(display, 0, 0, bmp, false)
display.show()

60.
Android Things
TensorFlow Sample
(18)
(18)
https://github.com/androidthings/sample-tensorflow-imageclassifier

61.
Camera

62.
Cucumbers (?!?) (19)
(19)
https://cloud.google.com/blog/big-data/2016/08/how-a-japanese-cucumber-farmer-is-using-deep-learning-and-
tensorflow

63.
Detect when
someone is
approaching

64.
Ultrasonic Sensor (HC-SR04)

65.
Ultrasonic Sensor
(HC-SR04)
1. Trigger
2. Echo

66.
No Android Things
compatible drivers

67.
Arduino to the rescue

68.
Arduino to the rescue

69.
Arduino to the rescue
void loop() {
distance = getDistanceInCentimeters();
Serial.println(distance);
delay(1000);
}

70.
Arduino to the rescue

71.
Read data from USB (20)
Hcsr04LiveData(this)
.observe({lifecycle}) { distanceInCm ->
Log.i(TAG, "Distance (cm): $distanceInCm")
}
(20)
https://github.com/Nilhcem/usbfun-androidthings

72.
HC-SR04
Hcsr04LiveData(this)
.observe({lifecycle}) { distanceInCm ->
if (distanceInCm < 25) {
takePicture()
}
}

73.
git commit -m "Kill reptilian when detected"
if (detected.isReptilian()) {
exterminate()
}

74.
Exterminate

75.
Option #1: Gun

76.
Servo motor

77.
Servo motor

78.
Servo motor

79.
PWM servo
compile 'com.google.android.things.contrib:driver-pwmservo:0.3'

80.
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

81.
Moving the servo
servo.angle = 42.0

82.
Option #2:
Flamethrower

83.
Flamethrower (21)
(21)
https://www.youtube.com/watch?v=fh6oJZZ27Ro

84.
Remote control
• Nearby Connections API
• Bluetooth LE
• Embedded http server
• Whatever you want

85.
Option #3: Chainsaw

86.
Relay module (22)
(22)
http://nilhcem.com/android-things/google-assistant-smart-home

87.
Magic happens here
relay.value = true

88.
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()
}

89.
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()
}

90.
Using Android Things
to Detect &
Exterminate
Reptilians

91.
Conclusion

92.
Android Things is Fun

93.
Easy to get started

94.
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

95.
Be a maker
Try Android Things, really

96.
Using Android Things to
Detect & Exterminate Reptilians
• Twitter:
@Nilhcem
• Slides:
bit.ly/reptilethings