My Doorbell Runs Swift - iOSDevCampDC 2017

Mobile is shaping up to be the platform of the future, but that doesn't mean that static is dead and buried. The Internet of Things movement is all about bringing the power of code to everyday objects. Believe it or not, it's easy to get Swift running where you least suspect it. I'll show you how I get a push notification every time someone rings my doorbell. I'll even answer that question, "Why?", with an impassioned caricature of the world of tomorrow. Your app will soon be at the center of a constellation of physical Things, here's how you can make the best of it.

Transcript

1. My Doorbell Runs Swift
   @huebnerob
   iOSDevCampDC 2017
   Rob Huebner
   

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2. Agenda
   • Internet of Things
   • DEMO
   • Hardware
   • Software
   • What’s next
   

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3. “Internet of Things”
   

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5. Example: Philips Hue Lights
   

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6. ✅ ✅
   
   

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7. Build Our Own Bridge
   

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8. But what are “Things™”?
   • Controlling systems with
   electronics
   • Caution ⚠ High Voltage!
   • Model them as simple circuits
   

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9. Simple Circuits
   • Power source
   • Input
   • Button
   • Output
   • Light
   

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10. Agenda
    ✓ Internet of Things
    • DEMO
    • Hardware
    • Software
    • What’s next
    

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11. DEMO
    

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13. DEMO
    

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14. Agenda
    ✓ Internet of Things
    ✓ DEMO
    • Hardware
    • Software
    • What’s next
    

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15. Hardware
    

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17. Hardware
    • What do we need to build our bridge?
    • Internet connectivity
    • Interface with “Things” (a.k.a. simple circuits)
    • Non-mobile
    

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18. Raspberry Pi
    • Small and energy efficient
    • Powerful ARM processor
    • Mount it anywhere
    • Runs Linux (which supports Swift!)
    • WiFi and Ethernet
    • General Purpose Input and Output
    (GPIO)
    

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19. What is GPIO?
    • “API for Electricity”
    • GPIO pins connect to circuits
    • Each pin can be an input or an output
    • Input: Read if it’s ON or OFF
    • Output: Set it ON or OFF
    

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20. Outputs
    1
    0
    HIGH
    LOW
    

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21. Inputs
    1
    0
    

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23. Agenda
    ✓ Internet of Things
    ✓ DEMO
    ✓ Hardware
    • Software
    • What’s next
    

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24. Software
    

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25. Setting up your Pi
    • Ubuntu Linux
    • Installing the Swift Toolchain
    • Installing dependencies
    • Network configuration
    • Helper guide
    •goo.gl/P5JKcy
    p ?
    

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26. Software Components
    • Interacting with Things
    • SwiftyGPIO
    • Interacting with the Internet
    • Server-side Swift (Vapor)
    • Push Notifications (Vapor-APNS)
    

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27. SwiftyGPIO
    • Interact with GPIO pins from Swift
    • Simple to Use
    • Integrates with other Swift libraries well
    

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28. Pin Handling
    let pin = SwiftyGPIO.GPIOs(for: .RaspberryPi3)[.P2]
    pin.direction = .OUT
    pin.value = 1
    pin.direction = .IN
    print(pin.value) // “0” or “1”
    

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29. Outputs
    1
    0
    pin.value = 1
    pin.value = 0
    pin.value = 0
    

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30. Inputs
    1
    0
    “0” “1” “0”
    print(pin.value)
    

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31. Inputs
    1
    0
    “0” “1” “0”
    “0” “1” “1” “1” “0”
    print(pin.value)
    

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32. Edges
    1
    0
    rising edge falling edge
    

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33. Input Handling
    pin.onRaising { pin in . . . }
    pin.onFalling { pin in . . . }
    pin.onChange { pin in . . . }
    

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34. Inputs
    1
    0
    pin.onRaising pin.onFalling
    pin.onChange pin.onChange
    

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35. Server Side Swift for IoT
    • Build a Web Server in Swift
    • Fundamentals are relatively constant
    • Routing requests and serving
    responses
    • Vapor
    • Works on Raspberry Pi
    

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36. Client API
    POST
    /led/toggle
    GET
    /button/state
    {
    “state”: 1
    }
    {
    “state”: 0
    }
    

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37. Push Notifications
    • Don’t poll your state
    • Alerts your client application immediately
    when a notable event occurs
    • Swift library: Vapor APNS
    

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38. Push Process
    1. Ask your user for permission
    2. Send the client’s device token to your bridge, save it
    3. When an event happens, create and submit a push payload
    

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39. Permission
    1. Ask your user for permission (in iOS Client)
    let center = UNUserNotificationCenter.current()
    center.requestAuthorization(options: [.alert]) { (granted, error) in
    if !granted { return }
    UIApplication.shared.registerForRemoteNotifications()
    }
    

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40. Device Token
    2. Send the client’s device token to your bridge
    func application(_ application: UIApplication,
    didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    var urlRequest = URLRequest(url: setTokenURL)
    urlRequest.httpBody = token
    urlRequest.httpMethod = "POST"
    URLSession.shared.dataTask(with: urlRequest) {
    // handle completion
    }.resume()
    }
    

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41. Push Payload
    3. When an event happens, send a push payload (on bridge)
    let message = ApplePushMessage(priority: .immediately,
    payload: Payload(message: “DingDong!"),
    sandbox: false)
    let result = apns.send(message, to: token)
    

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42. Success!
    

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43. Software Summary
    Vapor
    APNS
    SwiftyGPIO
    

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44. Swifty Doorbell
    

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45. Interaction Flow
    1. Doorbell rings
    2. Bridge sends push
    notification
    3. User taps “Door
    Open” button
    4. Bridge executes
    door open process
    

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46. Electrical Interface
    Function Pin Direction ON state OFF state
    Door Open 2 Output Door Unlocked Door Locked
    Bell Detector 3 Input Ringing Quiet
    

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47. Mapping the Flow
    BELL
    DOOR
    Send
    Push
    POST
    /door/open
    

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48. Agenda
    ✓ Internet of Things
    ✓ DEMO
    ✓ Hardware
    ✓ Software
    • What’s next
    

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49. What’s Next?
    

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50. Future Projects?
    

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52. developer.apple.com/homekit/specification
    

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53. Agenda
    ✓ Internet of Things
    ✓ DEMO
    ✓ Hardware
    ✓ Software
    ✓ What’s next
    

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54. Thanks!
    @huebnerob
    

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