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Device Discovery Messages

Messages relating to finding and getting information about devices connected to the system.

StartScanning​

Description: Client request to have the server start scanning for devices on all busses that it knows about. Useful for protocols like Bluetooth, which require an explicit discovery phase.

Introduced In Spec Version: 0

Last Updated In Spec Version: 0

Fields:

  • Id (unsigned int): Message Id

Expected Response:

  • Ok message with matching Id on successful request.
  • Error message on value or message error.

Flow Diagram:

Serialization Example:

[
  {
    "StartScanning": {
      "Id": 1
    }
  }
]

StopScanning​

Description: Client request to have the server stop scanning for devices. Useful for protocols like Bluetooth, which may not timeout otherwise.

Introduced In Spec Version: 0

Last Updated In Spec Version: 0

Fields:

  • Id (unsigned int): Message Id

Expected Response:

  • Ok message with matching Id on successful request.
  • Error message on value or message error.

Flow Diagram:

Serialization Example:

[
  {
    "StopScanning": {
      "Id": 1
    }
  }
]

ScanningFinished​

Description: Sent by the server once it has stopped scanning on all busses. Since systems may have timeouts that are not controlled by the server, this is a separate message from the StopScanning flow. ScanningFinished can happen without a StopScanning call.

In reality, this event is usually only useful when working with systems that can only scan for a single device at a time, like WebBluetooth. When on normal desktop/mobile APIs, it should be assumed that running StartScanning/StopScanning will be the main usage.

Introduced In Spec Version: 0

Last Updated In Spec Version: 0

Fields:

  • Id (unsigned int): Message Id

Expected Response:

None. Server-to-Client only.

Flow Diagram:

Serialization Example:

[
  {
    "ScanningFinished": {
      "Id": 0
    }
  }
]

RequestDeviceList​

Description: Client request to have the server send over its known device list, without starting a full scan.

Introduced In Spec Version: 0

Last Updated In Spec Version: 0

Fields:

  • Id (unsigned int): Message Id

Expected Response:

  • DeviceList message with matching Id on successful request.
  • Error message on value or message error.

Flow Diagram:

Serialization Example:

[
  {
    "RequestDeviceList": {
      "Id": 1
    }
  }
]