Introducing Pebble SDK 2.0 November 6th 2013

A MAJOR UPDATE New Tools SDK Overhaul New APIs

Introducing Pebble SDK 2.0 If you are watching live, you can ask questions On our IRC channel: #pebble on irc.freenode.net During our AMA on Reddit at 12pm PST today This is recorded and will be available on our YouTube channel and on the developer web site Friendly warning: This presentation is mostly intended for developers

New Tools Improving the developer experience CloudPebble Simplied build system Deploying from the command line Application logs Documentation

New Tools CloudPebble Now open-sourced and hosted by Pebble Technology

New Tools CloudPebble No installation - From zero to rst installed app in 60 seconds

New Tools Simplied build system One tool for all your Pebble development

New Tools Simplied build system $ pebble new-project helloworld Creating new project hello-world $ cd helloworld $ pebble build Memory usage: ============= Total app footprint in RAM: 822 bytes / ~24kb Free RAM available (heap): 23754 bytes 'build' finished successfully (0.351s)

New Tools Developer Connection Use the Pebble mobile application to install and debug apps.

New Tools Developer Connection $ export PEBBLE_PHONE=192.168.1.42 $ pebble install --logs [INFO [INFO [INFO [INFO ] ] ] ] Installation successful Enabling application logging... Displaying logs ... Ctrl-C to interrupt. D helloworld.c:58 Done initializing A very simple and reliable way to install and watch log messages

New Tools Documentation We have re-written almost all of Pebble Documentation Pebble documentation now includes: A Getting Started Guide Pebble Developer Guide with 11 chapters Pebble Mobile Developer Guide Pebble 2.0 Migration Guide API Reference for Pebble, iOS and Android

New Tools Improving the developer experience CloudPebble Simplied build system Deploying from the command line Application logs Documentation

SDK Overhaul Getting ready for bigger applications and an evolving SDK

SDK Overhaul Migrating to Pebble 2.0 Pebble 2.0 is a major evolution of Pebble 1.0 with lots of changes in the system and in the SDK Pebble 2.0 is not compatible with 1.0 apps Developers need to migrate their application to Pebble 2.0 Refer to Pebble 2.0 Migration Guide http://developer.getpebble.com/2/guides/migration-guide.html

SDK Overhaul Pebble application must provide some metadata through a JSON le in the project called appinfo.json Application name UUID Watchface / Watchapp Resources etc Application metadata

SDK Overhaul Using pointers and dynamic memory In Pebble OS 2.0, all the SDK structures are opaque. This means we can change them without you having to recompile your apps. You cannot allocate structures as global variables as you did in 1.0. You must use pointers and memory allocated dynamically by the system. All calls to _init() functions become are replaced by _create() calls Window my_window; window_init(&my_window); becomes Window *my_window; my_window = window_create();

SDK Overhaul Getting closer to standards: C/UNIX pbl_main() is now called main() PblTm is replaced by struct tm string_format_time() is replaced by strftime() Pebble does not support timezones yet but we introduce gmtime() and localtime() to prepare for timezone support. get_time() is replaced by localtime(time(NULL))

SDK Overhaul Enforcing a subscription based Event system Pebble 2.0 relies heavily on Events. You register to events with _register functions. All Pebble 1.x APIs have been updated: Timer, Tick, AppMessage, etc PebbleAppHandlers handlers = { .timer_handler = &handle_timer }; becomes timer = app_timer_register(1500, timer_callback, NULL);

SDK Overhaul Dynamic Memory Introducing two old friends: malloc() and free() Each application has its own heap and is cleaned automatically You can attach data to layers and windows (layer_create_with_data() and window_set_user_data()) Your total memory is ~24k. Your heap space is 24k minus app size. Pebble SDK includes tool to help you manage your memory: $ pebble build Memory usage: ============= Total app footprint in RAM: 822 bytes / ~24kb Free RAM available (heap): 23754 bytes ! $ pebble logs ... [INFO ] I Heap Usage for : Available Used Still allocated

SDK Overhaul Migration in a nutshell Use pebble convert-project to generate the new appinfo.json le Rename pbl_main() into main() Use pointers to structures instead of statically allocated structures Use the SDK APIs to allocate memory and initialize the structs Check the other APIs for changes Refer to Pebble 2.0 Migration Guide http://developer.getpebble.com/2/guides/migration-guide.html

SDK Overhaul Getting ready for bigger applications and an evolving SDK

New Frameworks Event Services A unique design pattern that communicates with Pebble OS subsystems

New Frameworks Event Services The App Focus Service lets you know when your app is covered by a modal window typedef void (*AppFocusHandler)(bool in_focus); ! void app_focus_service_subscribe(AppFocusHandler handler); void app_focus_service_unsubscribe();

New Frameworks Event Services The Bluetooth Connection Service lets you know when the watch is connected to the phone typedef void (*BluetoothConnectionHandler)(bool connected); void bluetooth_connection_service_subscribe(BluetoothConnectionHandler handler); void bluetooth_connection_service_unsubscribe(void); ! bool bluetooth_connection_service_peek(void);

New Frameworks Event Services The Battery State Service can let you know when the watch is plugged or unplugged typedef struct { uint8_t charge_percent; bool is_charging; bool is_plugged; } BatteryChargeState; ! typedef void (*BatteryStateHandler)(BatteryChargeState charge); void battery_state_service_subscribe(BatteryStateHandler handler); void battery_state_service_unsubscribe(); ! void battery_state_service_peek(void);

New Frameworks Event Services A unique design pattern that communicates with Pebble OS subsystems Bluetooth, App Focus, Battery Status Refer to Pebble 2.0 Event Services Guide http://developer.getpebble.com/2/guides/event-service-guide.html

New Frameworks Accelerometer Lets shake things up ... The Accelerometer framework is designed with all use cases in mind: user interaction for watchfaces, games, activity monitor, etc

New Frameworks Accelerometer Hardware accelerometer ! Able to detect taps Perform measurements at a given frequency Store samples to save CPU time

New Frameworks Accelerometer The simplest way to use the accelerometer is to register for tap events Those events are generated by the hardware and use very little energy void accel_tap_handler(AccelAxisType axism int32_t direction) { // Process tap on ACCEL_AXIS_X, ACCEL_AXIS_Y or ACCEL_AXIS_Z } ! void handle_init() { accel_tap_service_subscribe(&accel_tap_handler); } ! void handle_deinit() { accel_tap_service_unsubscribe(); }

New Frameworks Accelerometer You can register to receive raw events one at a time void accel_data_handler(AccelData *data, uint32_t num_samples) { process_sample(&data); } ! void handle_init() { accel_data_service_subscribe(1, &accel_data_handler); } ! void handle_deinit() { accel_data_service_unsubscribe(); }

New Frameworks Accelerometer The accelerometer API also supports storing samples on the hardware void accel_data_handler(AccelData *data, uint32_t num_samples) { // Process 10 events - every 1 second } ! void handle_init() { accel_data_service_subscribe(10, &accel_data_handler); accel_service_set_sampling_rate(ACCEL_SAMPLING_10HZ); }

New Frameworks Accelerometer You can also peek at the accelerometer when updating your UI This is the strategy we recommend for game developers void tick_handler() { AccelData data; accel_service_peek(&data); } ! void handle_init() { accel_data_service_subscribe(0, NULL); } void handle_deinit() { accel_data_service_unsubscribe(); };

New Frameworks Accelerometer The Accelerometer Service Tap events - Regular measures - Batch processing - Real time processing Refer to Pebble 2.0 Accelerometer Guide http://developer.getpebble.com/2/guides/accelerometer.html

New Frameworks Data Logging A better way to transfer data The data logging service is a transparent buer between your watch app and your phone that reliably and eciently carries your data.

New Frameworks Data Logging Your watchapp creates one or multiple data logging sessions and pushes data to those sessions. Using PebbleKit iOS and Android, your mobile app gets events when new data is available for download. Your data is managed by Pebble OS: saved on the watch lesystem, persisted if the user moves to another app, transferred in batches.

New Frameworks Data Logging You create a spool with a call to data_logging_create () DataSpoolRef my_data_spool; ! void handle_init() { logging_session = data_logging_create( /* tag */ 42, /* data type */ DATA_LOGGING_BYTE_ARRAY, /* length */ sizeof(AccelData), /* resume */ true ); }

New Frameworks Data Logging Use data_logging_log() to add data to the spool void accel_data_handler(AccelData *data, uint32_t num_samples) { DataLoggingResult r = data_logging_log(logging_session, data, num_samples); }

New Frameworks Data Logging Finally, use data_logging_finish() when you are done void handle_deinit() { data_logging_finish(logging_session); }

New Frameworks Data Logging - iOS You register to data spooling on iOS by providing a delegate to the dataLoggingService [[[PBPebbleCentral defaultCentral] dataLoggingService] setDelegate:self];

New Frameworks Data Logging - iOS The delegate implements methods to consume the data - (BOOL)dataLoggingService:(PBDataLoggingService *)service hasUInt32s:(const UInt32 [])data numberOfItems:(UInt16)numberOfItems forDataLoggingSession:(PBDataLoggingSessionMetadata *)sessionMetadata { // Return YES when the data has been processed. } ! - (void)dataLoggingService:(PBDataLoggingService *)service sessionDidFinish:(PBDataLoggingSessionMetadata *)sessionMetadata { // Session closed. }

New Frameworks Data Logging A better way to transfer data The data logging service is a transparent buer between your watch app and your phone that reliably and eciently carries your data. Refer to the Ocean Data Survey example Examples/data-logging-demo

New Frameworks Persistent Storage Store data on the watch Persistent storage is perfect to save user settings, cache data from the phone app, high scores, etc

New Frameworks Persistent Storage Every application get its own persistent storage space. Its size is limited to 4kB. Each value is associated to a uint32_t key. Persistent storage supports saving integers, strings and byte arrays. The maximum size of byte arrays and strings is dened by PERSIST_DATA_MAX_LENGTH (currently set to 256 bytes)

New Frameworks Persistent Storage To write data in persistent storage, call one of the persist_write functions: You should check the return value for error codes (anything but 0 is bad news) void handle_deinit() { persist_write_bool(TRUTH_KEY, true); persist_write_int(DOUGLAS_KEY, 42); persist_write_string(USERNAME_KEY, thomas); uint8_t byte_array[42]; persist_write_data(DATA_KEY, sizeof(byte_array), byte_array); }

New Frameworks Persistent Storage The function persist_exists(key) returns a boolean indicating if the key exists or not. To read data from persistent storage, use the persist_read functions void handle_init() { bool truth = persist_read_bool(TRUTH_KEY); int douglas_value = persist_read_int(DOUGLAS_KEY); char username[20]; persist_read_string(USERNAME_KEY, 20, username); uint8_t byte_array[42]; persist_read_data(DATA_KEY, sizeof(byte_array), byte_array); }

New Frameworks Persistent Storage You can use persist_delete() to remove a key from persistent storage

New Frameworks Persistent Storage Store data on the watch Persistent storage is perfect to save user settings, cache data from the phone app, high scores, etc Refer to Pebble Persistent Storage Guide http://developer.getpebble.com/2/guides/persistent-storage.html

New Frameworks PebbleKit JavaScript Expand the reach of your Pebble apps with JavaScript logic running on the phone Make http calls on the phone, process the reply and send it to your watchapp. Send notication. Use the phone GPS. Use a webview in the phone to provide a conguration screen to your application.

New Frameworks PebbleKit JavaScript Add a pebble-js-app.js le in your project Or use pebble new-project --javascript When Pebble mobile application installs your pbw, the JS is extracted and saved on the phone. Your JavaScript code is started with your watchapp/watchface and will run as long as your app is in the foreground on Pebble.

New Frameworks PebbleKit JavaScript Pebble sandbox provides API to receive messages from the watch, make http requests, send new messages to the watch, etc. On the watch, AppMessage APIs are used to receive and send data. PebbleKit JS is completely independent of the platform (iOS, Android).

New Frameworks PebbleKit JavaScript The sandbox provides a Pebble.addEventListener function to register for events. A ready event is red when your JavaScript is ready to execute. PebbleEventListener.addEventListener("ready", function(e) { startRemoteRequest(); } });

New Frameworks PebbleKit JavaScript Your JavaScript code can send notications to the watch: Pebble.showSimpleNotificationOnPebble(title, text) You can also use the standard console.log() calls to log messages to the Pebble console.

New Frameworks PebbleKit JavaScript Your JS code can also process messages coming from the watch through the appmessage event. PebbleEventListener.addEventListener("appmessage", function(e) { var temperatureRequest = e.payload.temperatureRequest; if (temperatureRequest) { fetchWeather(); } });

New Frameworks PebbleKit JavaScript To send messages to the watch, use Pebble.sendAppMessage() PebbleKit JS automatically transforms JS dictionaries to Pebbles Dictionary Pebble.sendAppMessage({ "icon": ICON_SUNNY, "temperature": "28oC"});

New Frameworks PebbleKit JavaScript The Pebble JavaScript sandbox provides the standard XMLHttpRequest method to make http calls. var req = new XMLHttpRequest(); req.open('GET', 'http://api.openweathermap.org/data/2.1/find/city?lat=37.830310&lon=-122.270831&cnt=1', true); req.onload = function(e) { if (req.readyState == 4 && req.status == 200) { if(req.status == 200) { var response = JSON.parse(req.responseText); var temperature = result.list[0].main.temp; var icon = result.list[0].main.icon; Pebble.sendAppMessage({ "icon":icon, "temperature":temperature + "u00B0C"}); } else { console.log("Error"); } } } req.send(null);

New Frameworks PebbleKit JavaScript Pebble sandbox provides several standard APIs: HTML5 Geolocation API through navigator.geolocation Local Storage APIs through window.localStorage

New Frameworks PebbleKit JavaScript Your application can show a Congure button on the phone screen When the user clicks on this button, the congure event is red The html page can return information: document.location.href = pebblejs:///close#some-data-set Pebble.addEventListener("showConfiguration", function() { console.log("showing configuration"); Pebble.openURL('http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-js/configurable.html'); }); Pebble.addEventListener("webviewclosed", function(e) { console.log("configuration closed"); });

New Frameworks PebbleKit JavaScript Expand the reach of your watchapp with JavaScript logic running on the phone Make http calls on the phone, process the reply and send it to your watchapp. Send notication. Use the phone GPS. Use a webview in the phone to provide a conguration screen to your application. Refer to Pebble JavaScript Guide http://developer.getpebble.com/2/guides/javascript-guide.html

WRAPPING UP

Updated Tools SDK Overhaul New Frameworks Cloud Pebble App Metadata Event Service pebble Following Standards Accelerometer Developer Connection Events based APIs Data Logging Application logs Dynamic Memory Persistent Storage Documentation 2.0 Migration Guide PebbleKit JS

Downloading the new SDK ! Available now on http://developer.getpebble.com/2/

ENJOY! Questions? ! #pebble on irc.freenode.net AMA on reddit