pebble-dash-api

dash-api

Current API version: 1.6.1

Current published Android app version: 1.6 (library 1.6.1 compatible)

Dash API (in reference to the Dashboard app) allows a Pebble developer to access some Android APIs through a shared Android app.

• Setting Up
• Get Data
• Set a Feature State
• Get a Feature State
• Testing
• Error Codes
• Changelog

How It Works

All apps that use the Dash API are serviced by the Dash API Android app. You should instruct your users to install this app in order for them to benefit from the Dash API.

This is a 'many to one' service, meaning that any number of watchfaces or watchapps can use the Dash API to show Android data or control Android features without a bespoke Android app needing to be written for each one. Once a user has installed the Android app, they can install as many Pebble apps that use the Dash API without any further Android app installation required.

Developers using this library should direct their users to install 'Dash API for Pebble' from the Google Play Store, or check that they have it installed already. The library will inform you of this if a request times out by delivering ErrorCodeUnavailable to your DashAPIErrorCallback.

Client Apps

These are the known apps that use the Dash API - check them out! If you are using the Dash API in your app, raise an issue or otherwise let me know, and I'll add your app here!

• Snowy - Pebble appstore

• Dual Gauge - Pebble appstore - Source

• Eventful - Pebble appstore - Source

Important Notes

• Since all messages to and from Pebble use the same outbox, developers should not attempt simultaneous requests with the Dash API. Once the callback has been received for one request it is safe to then make the next, etc.

• When using dash_api_check_is_available(), wait for ErrorCodeSuccess in the error_callback before making further requests. This is a good best practice to follow when your app opens and begins making queries to the Dash API.

Setting Up

1. Install the pebble package:

$ pebble package install pebble-dash-api

1. Include the library where appropriate:

#include <pebble-dash-api/pebble-dash-api.h>

1. When the app is initialising, set up AppMessage for Dash API. This uses the pebble-events package to play nice with other Pebble packages. Include the name of your app (used in the Android app), and a callback to receive ErrorCode values:

#define APP_NAME "My Dash API Client App"

static void error_callback(ErrorCode code) { 
  APP_LOG(APP_LOG_LEVEL_INFO, "Got ErrorCode %d", code);
}

static void init() {
  dash_api_init(APP_NAME, error_callback);
 
  /* other init code */
}

1. When all other packages using AppMessage are initialised (if any), open AppMessage for them all:

#include <pebble-events/pebble-events.h>

/* other library AppMessage init code, if any */
 
events_app_message_open();

1. Check the library is available at the other end:

This can be considered optional - all requests have a timeout and Bluetooth connectivity check built in.

static void error_callback(ErrorCode code) {
  if(code == ErrorCodeSuccess) {
    // Available! 
  } else if(code == ErrorCodeUnavailable 
         || code == ErrorCodeWrongVersion) {
    // Timed out, or was wrong version of the Android app 
  }
}
 
dash_api_check_is_available();

1. Interact with Android through one of dash_api_get_data(), dash_api_set_feature(), or dash_api_get_feature(). See the sections below for code examples.

Get Data

To get some data from Android, choose a DataType from the Available Data table below, and make a call to the API with a handler to receive the result:

static void get_callback(DataType type, DataValue result) {
  APP_LOG(APP_LOG_LEVEL_INFO, "Phone Battery:\n%d%%", result.integer_value);
}
 
dash_api_get_data(DataTypeBatteryPercent, get_callback);

Available Data

The table below details all the data items currently available via the Dash API. See the information below the table to learn how to read the received data.

Name	DataValue Type	Example Value	Added In Version
DataTypeBatteryPercent	integer_value	56	1.0
DataTypeWifiNetworkName	string_value	BTHub3-NCNR	1.0
DataTypeStoragePercentUsed	integer_value	22	1.0
DataTypeStorageFreeGBString	string_value	6.2 GB	1.0
DataTypeGSMOperatorName	string_value	Three UK	1.0
DataTypeGSMStrength	integer_value	68	1.0
DataTypeUnreadSMSCount	integer_value	2	1.2
DataTypeNextCalendarEventOneLine	string_value	14:00 Design Review	1.2
DataTypeNextCalendarEventTwoLine	string_value	24 Jul 14:00\nDesign Review	1.2

The value returned by DataTypeUnreadSMSCount may also count unread messages in apps other than the built in 'Messenger' Android app, as well as unread messages in archived conversations.

Using Received Data

DataValue is a structure of two members to enable multiple data types. For example, battery percentage will be read as an integer:

static void get_callback(DataType type, DataValue result) {
  int battery_percent = result.integer_value;
}

Whereas GSM operator name will be read as a string:

The string will only be valid for the duration of the callback, so should be copied out as required.

static void get_callback(DataType type, DataValue result) {
  static char s_buff[32];
  snprintf(s_buff, sizeof(s_buff), "GSM Operator: %s", result.string_value);
  APP_LOG(APP_LOG_LEVEL_INFO, "%s", s_buff);
}

Set a Feature State

To set the state of a feature, the client app will need to be granted permission in the Dash API Android app. The user will be notified and asked to switch it on within the app. This applies only to setting a feature state.

To set the state of an Android feature (for example, turning on WiFi):

static void set_callback(FeatureType type, FeatureState new_state) {
  APP_LOG(APP_LOG_LEVEL_INFO, "WiFi request successful!");
}
 
dash_api_set_feature(FeatureTypeWifi, FeatureStateOn, set_callback);

Get a Feature State

To get the current state of a feature (for example, the state of WiFi):

This will be a value from the FeatureState enum:

static void get_feature_callback(FeatureType type, FeatureState new_state) {
  APP_LOG(APP_LOG_LEVEL_INFO, "WiFi state now %d!", new_state);
}
 
dash_api_get_feature(FeatureTypeWifi, get_feature_callback);

Available Features

The table below details all the Android features that can be interacted with via the Dash API. See the information below the table to learn how to read the received data.

When using dash_api_get_feature(), the callback parameters will reflect the current state of the feature.

When using dash_api_set_feature(), the callback parameters will mirror those of the request.

Name	Set Values	Added In Version
FeatureTypeWifi	FeatureStateOn, FeatureStateOff	1.0
FeatureTypeBluetooth	FeatureStateOff	1.0
FeatureTypeRinger	FeatureStateRingerLoud, FeatureStateRingerVibrate, FeatureStateRingerSilent	1.0
FeatureTypeAutoSync	FeatureStateOn, FeatureStateOff	1.0
FeatureTypeHotSpot	FeatureStateOn, FeatureStateOff	1.0
FeatureTypeAutoBrightness	FeatureStateOn, FeatureStateOff	1.0

Since the only sensible Bluetooth instruction is to turn it off, there may not be a callback when using FeatureTypeBluetooth. You should assume that it has been turned off.

FeatureTypeHotSpot may take a few seconds to turn on and off, depending on the phone model.

Testing

If testing in the Pebble SDK emulator, or if an Android phone is not available, you can rig up fake responses as if they came from the Dash API. See any of the dash_api_fake_ family of functions to learn how to use them.

Fake responses should be triggered through these functions immediately (or after a suitable delay up to 10 seconds for realism), to fit the request-response model. For example:

const DataType type = DataTypeUnreadSMSCount;
dash_api_get_data(type, get_data_callback);
 
#if defined(TEST)
dash_api_fake_get_data_response(type, 5, NULL);
#endif

You can also see all the requests being made by setting dash_api_log_requests(true); after initializing.

Error Codes

When a request fails, the reason will be communicated over app logs, as well as by delivering a ErrorCode value to the DashAPIErrorCallback registered with dash_api_init(). The table below describes these values.

Code	Description	Added In Version
ErrorCodeSuccess	The request was made successfully. Used for a dash_api_check_is_available() response.	1.1
ErrorCodeSendingFailed	The sending of the request failed, or there was no connection.	1.1
ErrorCodeUnavailable	The request timed out or the Android app was unavailable, or not installed.	1.1
ErrorCodeNoPermissions	This app has not been permitted in the Dash API Android app.	1.1
ErrorCodeWrongVersion	An old or incompatible version of the Dash API Android app is installed.	1.1

Use dash_api_error_code_to_string() to get an appropriate string to show to the user in case of an error above.

Changelog

1.0

• Initial release.

1.0.1

• Update README.md on NPM.

1.1

• Add app_name and DashAPIErrorCallback to dash_api_init() (formerly dash_api_init_appmessage()).
• Change signatures of the main callbacks, directed failed result of requests to the DashAPIErrorCallback.
• Add permission switches in the Android app for clients that wish to set a feature state. Reading data is unaffected, and does not require permission.
• Added a timeout mechanism to inform when the Android app may be unavailable.
• Added dash_api_check_is_available() to check the library is available. ErrorCodeSuccess will be delivered to the DashAPIErrorCallback if it is available.

1.1.1

• Update README.md on NPM.

1.2

• Add <= version check instead of ==. This means apps built with 1.1 will be served by 1.2, and up.
• Add DataTypeUnreadSMSCount, DataTypeNextCalendarEventOneLine, and DataTypeNextCalendarEventTwoLine.

1.3

• Add dash_api_fake_ family of functions to allow faking of responses when testing in the emulator, or when an Android phone isn't available.
• Add check that dash_api_init() has been called before any requests can be made.
• Add dash_api_error_code_to_string().

1.3.1

• Fix timeout when faking a response immediately after making a request.

1.4.0

• Build for Diorite with SDK 4.0.

1.5.0

• Add dash_api_log_requests().

1.6.0

• Update pebble-packet to notify failed packet sends better.

1.6.1

• Fix dependency error.

1.7.0

• Built with 4.2-beta5 for Emery platform.

TODO

These items are desirable, but not guaranteed to be added.

• Enable concurrent requests (sacrifice switch for checking for all types)
• Music control
• Next Android alarm time
• Provide a template Window to show users that they need to update the Android app.