The document outlines updates from the 2015 Pebble Developer Retreat regarding PebbleKit iOS 3.0, introducing 8k app messages that allow for faster communication and compatibility with Pebble Time Round via Bluetooth Low Energy. It details breaking API changes, best practices for upgrading, and recommendations for handling app messages and sessions. The new framework provides improved performance, easier implementation, and better integration with various Pebble apps.

1. 2015 Pebble Developer Retreat
PebbleKit iOS 3.0
Marcel Jackwerth, iOS Engineer

2. Outline
• Recap: What is PebbleKit?
• What is new?
• 8K App Messages
• Support for Pebble Time Round
• Isolated Sessions via Bluetooth Low Energy
• Swift 2.0, Bitcode
• What are the breaking API changes?
• How do I upgrade?

3. What is PebbleKit?
And when should I use it?

5. What’s new?
8KApp Messages
with up to 8000 bytes
in both directions
Bluetooth LE Connectivity

6. App Messages
• Less data splitting needed → easier to work with
• Less waiting on ACKs → reduced overhead, up to 5x faster
• Optimal size depends on your use-case
8K

7. Good: Check Capabilities 8K
[watch getVersionInfo:^(PBWatch *watch, PBVersionInfo *info) {
BOOL supports8k =
(info.remoteProtocolCapabilitiesFlags &
PBRemoteProtocolCapabilitiesFlagsAppMessage8kSupported) != 0;
if (supports8k) {
// …
}
} onTimeout:nil];

8. Avoid: Maximum Sizes 8K
const uint32_t inbound = app_message_inbox_size_maximum();
const uint32_t outbound = app_message_outbox_size_maximum();
app_message_open(inbound, outbound);
⚠
This will reduce your heap size by 16,000 bytes
if your watch app is compiled with the latest SDK
and your companion app uses the new PebbleKit!

9. Best: Communicate Sizes 8K
const uint32_t inbound = MIN(512, app_message_inbox_size_maximum());
const uint32_t outbound = MIN(256, app_message_outbox_size_maximum());
app_message_open(inbound, outbound);
DictionaryIterator *iter;
app_message_outbox_open(&iter);
Tuplet value = TupletInteger(KEY_INIT_INBOX_SIZE, inbound);
dict_write_tuplet(iter, &value);
app_message_outbox_send();

10. What’s new?
8KApp Messages
with up to 8000 bytes
in both directions
Bluetooth LE Connectivity

11. Bluetooth Low Energyaka
Isolated App SessionCompatibility with
Pebble Time Round

12. Shared App Session

13. Shared App Session
Pandora
iOS App
Shared
Session
Pandora
Pebble App

14. Shared App Session
Pandora
iOS App
Shared
Session
Pandora
Pebble App

15. Shared App Session
Pandora
iOS App
runkeeper
iOS App
Shared
Session
Pandora
Pebble App
runkeeper
Pebble App

16. Shared App Session
Pandora
iOS App
runkeeper
iOS App
Shared
Session
Pandora
Pebble App
runkeeper
Pebble App

17. Shared App Session
Pandora
iOS App
runkeeper
iOS App
Shared
Session
Pandora
Pebble App
runkeeper
Pebble App

18. Isolated App Sessions
Pandora
iOS App
Pandora
Pebble App

19. Isolated App Sessions
Pandora
iOS App
Pandora
Pebble App
f01d…

20. Isolated App Sessions
Pandora
iOS App
runkeeper
iOS App
Pandora
Pebble App
f01d…
runkeeper
Pebble App
b13a…

21. Launch App from Watch
Pandora
Pebble App
Requires UIBackgroundModes to contain
“bluetooth-peripheral” and “bluetooth-central”

22. Launch App from Watch
Pandora
Pebble App
f01d…
Requires UIBackgroundModes to contain
“bluetooth-peripheral” and “bluetooth-central”

23. Launch App from Watch
Pandora
iOS App
Pandora
Pebble App
f01d…
Requires UIBackgroundModes to contain
“bluetooth-peripheral” and “bluetooth-central”

24. Breaking API Changes
• App UUIDs are now of type NSUUID (was: NSData)
• PebbleCentral starts in a cold state
•You have to run it so that it scans for watches
•lastConnectedWatch will not contain a connected Pebble
before nor immediately after you called run (was possible
before) - wait for pebbleCentral:watchDidConnect:
after you called run.

25. Breaking API Changes
central.delegate = self;
uuid_t appUUIDBytes;
NSUUID *appUUID = [[NSUUID alloc] initWithUUIDString:”f00d…”];
[appUUID getUUIDBytes:appUUIDBytes];
central.appUUID = appUUIDBytes;
Before

26. Breaking API Changes
After
central.delegate = self;
NSUUID *appUUID = [[NSUUID alloc] initWithUUIDString:”f00d…”];
central.appUUID = appUUID;
[central run];

27. Bad: Run, Configure, Manual Check
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[[PBPebbleCentral defaultCentral] run];
[PBPebbleCentral defaultCentral].appUUID = [NSUUID …];
PBWatch *watch = [PBPebbleCentral defaultCentral].lastConnectedWatch;
if (watch.isConnected) { … }
return YES;
}

28. Good: Configure, Run, React
- (BOOL)application:(UIApplication *)application
willFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[PBPebbleCentral defaultCentral].delegate = self;
[PBPebbleCentral defaultCentral].appUUID = [NSUUID …];
[[PBPebbleCentral defaultCentral] run];
}
- (void)pebbleCentral:(PBPebbleCentral *)central
watchDidConnect:(PBWatch *)watch { … }

29. • Nullability Annotations
• Generics
Swift 2.0

30. • Xcode 7.0.1 started to claim that
it isn’t (when using CocoaPods
and building an Archive)
• If you run into any issues we
recommend that you disable it
with ENABLE_BITCODE=NO
Bitcode included
$

31. Still necessary to be
compatible with Pebble and
Pebble Steel
MFi


32. How to Update
pod “PebbleKit”, “~> 3.0.0”
Or just replace the PebbleKit.framework
with its new version manually, available here:
https://github.com/pebble/pebble-ios-sdk/releases
Podfile

33. CHMultiDictionary CHMutableDictionary
DDASLLogger DDFileLogger DDLog DDTTYLogger
NSJSONSerialization+ObjectWithNString
NSJSONSerialization+PBJSONHelpers
NSString+HexData
UIDevice-Hardware
You can remove it from your project if you don’t use any of the
classes or methods that it contained:
PebbleVendor.framework

34. Recap
• Why?
•8K App Messages, Better Background Experience
•Support Pebble Time Round and be ready when other
Pebble models switch to Bluetooth Low Energy
• How?
•Get the new PebbleKit.framework
•Set appUUID, then [central run]

35. Questions?

36. Licenses & Attribution
• Isolation Icon by Griffin Mullins
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