Core Bluetooth - Apple Inc. · 2016. 7. 10. · Evolution of Core Bluetooth Core Bluetooth in iOS 7 Code Demo Tips and Best Practices. BLE State of the Union Evolution of Core Bluetooth

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Session 703

Core Bluetooth

Jason ConnCode Monkey & Radio Sponge

Brian TuckerBluetooth SIG Grand Wizard

Renaud LienhartKeeper of the Code & General Curmudgeon

BLE State of the Union

Evolution of Core Bluetooth

Core Bluetooth in iOS 7

Code Demo

Tips and Best Practices




Code Demo





Code Demo





Code Demo





Code Demo





Code Demo


BLE: State of the Union

Brian TuckerBluetooth SIG Grand Wizard

Source ABI Research 2013

Projected BLE Accessories Shipped1 Billion+

Projected BLE Accessories Shipped

0

750

1,500

2,250

3,000

2012 2013 2014 2015 2016 2017 2018

Source ABI Research 2013

1,009,000,000 Devices

Proximity

Security

Automation

Health Care Sports/Fitness

Entertainment Toys

Pay Systems Time Services



Observer, Central, Client

• CBCentralManager■ Discover peripherals■ Connect

• CBPeripheral■ Access remote services

iOS 5

Broadcaster, Peripheral, ServeriOS 6

• CBPeripheralManager■ Host services■ Advertise information■ Field CBCentral requests

• Peripheral database caching

LE, EvolvedCore Bluetooth in iOS 7.0

Ch-ch-ch-changes

• Simpler device management• Smarter peripherals• Performance improvements•Application persistence• Built-in services

What’s New

That is the questionTo Simulate, or Not to Simulate

• Emerging market • Limited hardware available

■ No iOS devices

•Development difficult


• Exploding market•Many LE-compatible devices

■ All iOS hardware■ Macbook, Mac mini

• Third-party development kits



■ All iOS hardware■ Macbook, Mac mini




■ All iOS hardware■ Most Mac hardware


Handling centrals and peripheralsSimpler Device Management

• Bye, bye CoreFoundation


@property(readonly, nonatomic) CFUUIDRef *UUID;




@property(readonly, nonatomic) NSUUID *identifier;




@property(readonly, nonatomic) NSUUID *identifier;

• Identifiers created at discovery

Retrieving peripherals, todaySimpler Device Management

CBCentralManager <CBCentralManagerDelegate>




retrievePeripherals:



didRetrievePeripherals:







retrieveConnectedPeripherals





retrieveConnectedPeripherals

didRetrieveConnectedPeripherals:

Retrieving peripheralsSimpler Device Management





retrievePeripheralsWithIdentifiers:







CBCentralManager


<CBCentralManagerDelegate>

, the iOS 7 way


CBCentralManager


retrieveConnectedPeripheralsWithServices:


, the iOS 7 way


CBCentralManager


retrieveConnectedPeripheralsWithServices:

connectPeripheral:options:


, the iOS 7 way

Smarter Peripherals

Smarter Peripherals

•More connection-aware@property(readonly) BOOL isConnected;

typedef NS_ENUM(NSInteger, CBPeripheralState) { CBPeripheralStateDisconnected = 0, CBPeripheralStateConnecting, CBPeripheralStateConnected };

@property(readonly) CBPeripheralState state;

Smarter Peripherals

•More connection-aware@property(readonly) BOOL isConnected;

typedef NS_ENUM(NSInteger, CBPeripheralState) { CBPeripheralStateDisconnected = 0, CBPeripheralStateConnecting, CBPeripheralStateConnected };

@property(readonly) CBPeripheralState state;

Smarter Peripherals

Smarter Peripherals

• Better service invalidation

Smarter Peripherals

• Better service invalidation(void)peripheralDidInvalidateServices:(CBPeripheral *)

Smarter Peripherals

• Better service invalidation(void)peripheralDidInvalidateServices:(CBPeripheral *)

(void)peripheral:(CBPeripheral *)didModifyServices:(NSArray *)

LE, EvolvedCore Bluetooth in iOS 7.0


Performance Improvements

ServiceHeart Rate Monitor

CharacteristicHeart Rate Measurement

Database caching, todayPerformance Improvements





Characteristic Value190

DescriptorClient Configuration


• Introduced in iOS 6 ServiceHeart Rate Monitor







• Introduced in iOS 6• Increases speed and battery life








• Introduced in iOS 6• Increases speed and battery life• Cache services and characteristics







Database caching, in iOS 7Performance Improvements









• Cache characteristic descriptors










• Cache characteristic descriptors• Caching for characteristic values?





















■ Provide last-known characteristic values and descriptor values












■ Provide last-known characteristic values and descriptor values

• Free!












Sending dataPerformance Improvements

115 BPM


115 BPM


115 BPM


115 BPM


115 BPM


Mon Tues Weds Thurs

58

70

43

55

96

53

26

17

Mon Tues Weds Thurs

50%

28%

14%9%

115 BPM


Mon Tues Weds Thurs

58

70

43

55

96

53

26

17

Mon Tues Weds Thurs

50%

28%

14%9%



• Support MTU exchange request


• Support MTU exchange request•Maximum amount of data per PDU


• Support MTU exchange request•Maximum amount of data per PDU• Send more data at a time


Sending data

Default MTU23 bytes


Sending data

Default MTU23 bytes


Sending data

Default MTU23 bytes

Increased MTU??? bytes


Sending data

Default MTU23 bytes

Increased MTU??? bytes




•When central, ask for larger MTU


•When central, ask for larger MTU•Up to 20% increase in throughput


•When central, ask for larger MTU•Up to 20% increase in throughput• Free!

Performing long-term actionsPerformance Improvements

Performing long-term actionsPerformance Improvements

Living in a multitasking worldPerforming Long-Term Actions


• Backgrounding modes


• Backgrounding modes■ App communicates using CoreBluetooth


• Backgrounding modes■ App communicates using CoreBluetooth■ App shares data using CoreBluetooth



• Background applications can be terminated by system



• Background applications can be terminated by system• Some use-cases take hours

Our solutionPerforming Long-term Actions


• System watches application state


• System watches application state•When application is terminated…



■ If cause is memory pressure



■ If cause is memory pressure■ If application is performing long-term action(s)




• System acts as application proxy




• System acts as application proxy•When needed, application is re-launched

State Preservation and Restoration


•Opt-in


•Opt-in• Supported by CBCentralManager and CBPeripheralManager


•Opt-in• Supported by CBCentralManager and CBPeripheralManager•Minimal implementation

■ Provide unique “identifier” for manager■ Implement new delegate method

A picture is worth a thousand wordsState Preservation and Restoration


• Snapshot taken before termination


• Snapshot taken before termination• CBCentralManager



■ Scanning state



■ Scanning state■ Pending/active connections



■ Scanning state■ Pending/active connections■ Peripheral subscriptions




• CBPeripheralManager




• CBPeripheralManager■Advertising state




• CBPeripheralManager■Advertising state■ Published services




• CBPeripheralManager■Advertising state■ Published services■Central subscriptions

Back from the deadState Preservation and Restoration



• Events that system can’t handle trigger application re-launch


• Events that system can’t handle trigger application re-launch■ Peripheral connects, central subscribes, notification received, etc.



•Application re-launched into background, running



•Application re-launched into background, running■ Re-instantiates appropriate manager object(s)



•Application re-launched into background, running■ Re-instantiates appropriate manager object(s)■ Delegate callback provides all preserved state



•Application re-launched into background, running■ Re-instantiates appropriate manager object(s)■ Delegate callback provides all preserved state■ Power on event



•Application re-launched into background, running■ Re-instantiates appropriate manager object(s)■ Delegate callback provides all preserved state■ Power on event■ Delegate callback for triggering event

DemoAdding State Preservation and Restoration Support


Bluetooth Low Energy graduatesBuilt-in Services


GATT ClientBuilt-in Services


•HID Over GATT Profile ■ HID, Battery, Device Information services


•HID Over GATT Profile ■ HID, Battery, Device Information services

•Works just like Bluetooth Classic■ Managed from Bluetooth Settings■ iOS automatically reconnects paired peripherals

GATT ServerBuilt-in Services


• Battery Service


• Battery Service• Current Time Service

■ Accurate time and date■ Time zone information


• Battery Service• Current Time Service

■ Accurate time and date■ Time zone information

•One more thing…

Notifications—the problemsBuilt-in Services


•Message Access Profile (MAP)


•Message Access Profile (MAP)■ Developed for an automotive usage


•Message Access Profile (MAP)■ Developed for an automotive usage■ Very constrained: SMS, MMS, Email



•Alert Notification Service



•Alert Notification Service■ Very limited




• Custom app tailored to a specific accessory




• Custom app tailored to a specific accessory■ Heavyweight




• Custom app tailored to a specific accessory■ Heavyweight■ Data limited to what the sandbox allows

Notifications—our solutionBuilt-in Services


•Apple Notification Center Service


•Apple Notification Center Service■ Apple-specific


•Apple Notification Center Service■ Apple-specific■ Notification about any events on your phone



■ Incoming and Missed calls, Voicemails



■ Incoming and Missed calls, Voicemails■ Instant messages, Emails



■ Incoming and Missed calls, Voicemails■ Instant messages, Emails■ Calendar alerts



■ Incoming and Missed calls, Voicemails■ Instant messages, Emails■ Calendar alerts■ App notifications




■ System automatically reconnects




■ System automatically reconnects ■ Detailed specification posted on the developer portal soon

Apple Notification Center ServiceBuilt-in Services

New iMessage

New iMessageNew Social Notification, UID=1


GetAttributes(UID=1,Title,Msg)



Title=”Jason”,Msg=”Beers?”




Alert User




iMessage Read

Alert User




iMessage Read Notification Removed, UID=1

Alert User




iMessage Read Notification Removed, UID=1

Alert User

Dismiss Alert



• Core Bluetooth needs to know if you intend to use CBPeripherals—keep a reference to them


• Core Bluetooth needs to know if you intend to use CBPeripherals—keep a reference to them• Scanning and connection requests do not time out


• Core Bluetooth needs to know if you intend to use CBPeripherals—keep a reference to them• Scanning and connection requests do not time out• CBPeripheral and CBCentral conform to NSCopying and can be used as dictionary keys


• Core Bluetooth needs to know if you intend to use CBPeripherals—keep a reference to them• Scanning and connection requests do not time out• CBPeripheral and CBCentral conform to NSCopying and can be used as dictionary keys•Do not touch Client Configuration Characteristic Descriptors directly


• Core Bluetooth needs to know if you intend to use CBPeripherals—keep a reference to them• Scanning and connection requests do not time out• CBPeripheral and CBCentral conform to NSCopying and can be used as dictionary keys•Do not touch Client Configuration Characteristic Descriptors directly•Do not game the background mechanisms

Bluetooth best practices

http://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf

Apple Guidelines

Core Bluetooth Programming Guide

Finally!

Apple Guidelines

Craig KeithleyMFi & I/O Technology [email protected]

Stephen ChickiPhone [email protected]

Developer ProgramsMFi Programhttp://developer.apple.com/mfi/

More Information

mailto:[email protected]

mailto:[email protected]

Bluetooth Accessory Design Guidelineshttp://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf

Reporting Bugshttp://bugreport.apple.com

Apple Developer Forumshttps://devforums.apple.com/community/ios/core/cbthttps://devforums.apple.com/community/mac/coreos/cbt

Bluetooth Developer Sitehttp://developer.bluetooth.org

More Information



http://bugreport.apple.com

http://bugreport.apple.com

https://devforums.apple.com/community/ios/core/cbt




What’s New in Core Location PresidioThursday 11:30AM

Related Sessions

Designing Accessories for iOS and OS X Nob HillTuesday 10:15AM

Labs

iOS and OS X Accessories Lab Core OS Lab BThursday 9:00AM

iOS and OS X Accessories Lab Core OS Lab ATuesday 11:30AM

ProximitySecurityAutomationHealth CareSports/FitnessEntertainmentToysPay Systems

Proximity

Security

Automation


Entertainment

Toys

Pay Systems

Proximity

Security

Automation


Entertainment

Toys

Pay Systems

Connect the World

Documents

Core Bluetooth - Apple Inc. · 2016. 7. 10. · Evolution of Core Bluetooth Core Bluetooth in iOS 7 Code Demo Tips and Best Practices. BLE State of the Union Evolution of Core Bluetooth