Watch BLE (Bluetooth Low Energy) Connection

Communication layer between a Flutter project for Android and IOS and a companion wearable app with Bluetooth Low Energy (BLE).

This will send and recieve messages and/or data to the platform specific wearable communication methood. It uses the wearable data layer and messaging API’s on android devices and WCSession on IPhones


? Android

  • add implementation '' to the app level build.gradle

  • make sure that the applicationId of your WearOS app is the same as the one on your phone app


How to use

  • For information on how to access the sent data on wearable devices please see the example project
  • It is recommended to not rely on instantaneous transfer of data on IOS as applicationContext waits for a “low intensity situation” to set this value between app and watch

? Sending messages

Use the static method WatchConnection.sendMessage(Map<String, dynamic> message); to send a single shot message.

  • on android the path "/MessageChannel" will be used for all messages

example send message

  "text": "Some text",
  "integerValue": 1

? Recieve message

Use the static method WatchConnection.listenForMessage; to register a message listener function.

  • (android specific) if the message data is a string then the library will assume it is JSON and try to convert it. if that operation fails the message data will be sent to the listener unchanged.

Recieve message example

// msg is either a Map<String, dynamic> or a string (make sure to check for that when using the library)
WatchListener.listenForMessage((msg) {

? set data item (datalayer/userConfig)

Use the static method WatchConnection.setData(String path, Map<String, dynamic> message); to set a data item with specified path (use wearOS compatible data layer paths)

  • (IOS specific) the path variable is used as a key within the application context dictionary
  • (IOS specific) data transfer is not instant and will wait for a “low intensity” moment. use this function only to set permanent low priority information

example set data

    "name": "Nicolas Cage",
    "awesomeRating": 100

? listen to data events

Use the static method WatchConnection.listenForDataLayer; to register a data listener function.

  • (android specific) if the data is a string then the library will assume it is JSON and try to convert it. if that operation fails the data will be sent to the listener unchanged.

example listen for data

// data should be a Map<String, dynamic> but can also be a string under exceptional circumstances
WatchListener.listenForDataLayer((data) {

? notes

  • currently does not support nested data structures on android. Therefore it is recommended to send complex items as json strings to be parsed on the recieving end
  • Supported types in communications are
    • Strings
    • Integers
    • Floats
    • Double
    • Long
    • Boolean
    • Single type lists of strings, floats, ints or longs


?? Afriwan Ahda ? Email


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