B4A Library BLE2PeripheralEnhanced2 - BLE2Peripheral with multiple services

BLE2PeripheralEnhanced2

BLE2PeripheralEnhanced2 is an update to Peter Simpson's BLE2PeripheralEnhanced library, which itself was an update to Erel's BLE2Peripheral library. My main addition is to allow for an arbitrary number of services to be defined. I won't duplicate the explanations that can be found in those posts.

The library is backwards compatible with Erel's original library with the one exception that the Write command now has to specify the characteristic being written to. So in Erel's original demo project, the two instances of:

peripheral.Write(Null, Data)

need to be changed to:

peripheral.Write(Null, Peripheral.UUID("1001"), Data)

(.UUID is a helper function to convert a short form UUID to its long form.)

The main change to Peter's library is that his functions: CreatePrimaryServiceUUID, CreateCharacteristicUUIDs, SetCharacteristicReadValues have been replaced with:

CreateUUIDs (UUIDs As Map, CharacteristicsReadValues As Map) As Boolean

UUIDs is a map defining the services and their characteristics. The specification of each characteristic is identical to Peter's approach. The optional characteristic read values are now defined in a map.

As an example, to create BLE standards compliant heart rate and battery services:

    Dim UUIDs, readValues As Map
    Dim characteristicsHR, characteristicsBattery As List
    UUIDs.Initialize
    readValues.Initialize
    characteristicsHR.Initialize
    characteristicsHR.AddAll(Array As String(Peripheral.UUID("2a37") & ",True,False,True"))
    UUIDs.Put(Peripheral.UUID("180d"), characteristicsHR)
    characteristicsBattery.Initialize
    characteristicsBattery.Add(Peripheral.UUID("2a19") & ",True,False,True")
    UUIDs.Put(Peripheral.UUID("180f"), characteristicsBattery)
    readValues.Put(Peripheral.UUID("2a37"), "0") 'a default heart rate of 0bps
    Dim allgood As Boolean=Peripheral.CreateUUIDs(UUIDs, readValues)

Using an app like BLE Scanner, you should find that your app is exposing the two standard services:

Note that calling CreateUUIDs overwrites the default service, i.e. the one presented in Erel's original post. If you need the default service in addition to new ones, add that service and characteristics to the UUIDs map before passing it to CreateUUIDs, as follows:

    Dim characteristicsDefault As List
    characteristicsDefault.Initialize
    characteristicsDefault.AddAll(Array As String(Peripheral.UUID("1001") & ",True,False,True", Peripheral.UUID("1002") & ",False,True,False"))
    UUIDs.Put(Peripheral.UUID("0001"), characteristicsDefault)

I have also added a few new capabilities that may be useful: UUID (already mentioned above), logging (selected in the Initialize2 method) and an optional white list specifying devices that can connect to your services, AllowedAddresses.



Ble2PeripheralEnhanced2

Author: CaptKronos
Version: 1.0

• Ble2PeripheralEnhanced2
  Allows to configure the device as a BLE peripheral device. Other central devices can connect to this device.
  Only supported by some devices running Android 5+. Make sure to check IsPeripheralSupported property.
  Based on Peter Simpson's BLE2PeripheralEnhanced library, which itself was based on Erel's BLE2Peripheral library.
  • Events:
    • ConnectionStatus (DeviceId As String, ConnectionState As Integer)
    • NewData (DeviceId As String, Data() As Byte)
    • NewData2 (DeviceId As String, Data() As Byte, CharacteristicUUID As String, DataAsStr As String, DataAsHex As String, DataAsBin As String)
    • Start (Success As Boolean)
    • Subscribe (DeviceId As String)
    • Unsubscribe (DeviceId As String)
  • Fields:
    • GetCharacteristicUUID As String
      
    • GetDataAsBinary As String
      
    • GetDataAsString As String
      
  • Functions:
    • Close
      Always call close to ensure the BLE services are properly closed down
    • CreateUUIDs (UUIDs As Map, CharacteristicsReadValues As Map) As Boolean
      UUIDs - defines the Primary Service UUIDs (the map keys) and a list of strings specifying the corresponding Characteristic UUIDs and properties (the map values). Each Characteristic should be formatted as a CSV string consisting of: UUID (String), Read (Boolean), Write (Boolean), Notify (Boolean)
      CharacteristicsReadValues - sets the default read value for the characteristics. The map keys are the characteristic UUIDs and the keys' values are the default read values. If there are no default values, pass null.
      Example: to create a heart rate service with a heart rate measurement characteristic:
      CharacteristicsList.AddAll(Array As String(Peripheral.UUID("2a37") & ",True,False,True"))
      UUIDsMap.Put(Peripheral.UUID("180d"), CharacteristicsList)
      ReadValuesMap.Put(Peripheral.UUID("2a37"), "0") 'initial heart rate of 0 bps
      Dim success As Boolean=Peripheral.CreateUUIDs(UUIDsMap, ReadValuesMap)
    • GetDataAsHexadecimal (UseCommas As Boolean) As String
      Retrieves the latest received data formatted as hex.
      If UseCommas=true, separate bytes with commas
    • Initialize (EventName As String, Ble As BleManager2)
      Initializes the object.
    • Initialize2 (EventName As String, Ble As BleManager2, logging As Boolean)
      Initializes the object and logging.
    • Start (Name As String)
      Starts advertising. The name will be set as the device Bluetooth name. Pass an empty string to keep the current name.
      The Start event will be raised.
    • Start2 (Name As String, Settings As android.bluetooth.le.AdvertiseSettings)
      Similar to Start. Allows overriding the default settings.
    • UUID (ShortName As String) As String
      Converts a short form UUID to its long form
      UUID("0001") -> "00000001-0000-1000-8000-00805f9b34fb"
    • Write (Centrals As List, UUID As String, Data As Byte())
      Writes data to subscribed devices of the characteristic with specified UUID.
      Centrals - Target devices. Pass Null to send to all subscribed devices.
      Warning - Unless you have changed the MTU size (e.g. manager.RequestMtu(50) [Manager As BleManager2]), only the first 20 bytes will be sent.
  • Properties:
    • AllowedAddresses As java.util.ArrayList [write only]
      If set, limits connections to devices with addresses on the provided list
      Example:
      AllowedAddressesList.Addall(Array As String("7B:47:33:23:E2:FE", "7A:79:16:F5:49:E5" ))
      Peripheral.AllowedAddresses=AllowedAddressesList
    • IsPeripheralSupported As Boolean [read only]
      Checks whether peripheral mode is supported.
    • ManufacturerData As Map
      Gets or sets the manufacturer specific data that will be advertised.
      Each item in the map should have a positive int number as the key and an array of bytes as the value.
    • MultipleConnections As Boolean [write only]
      If false, only one device can connect at a time. (Default is true).

 

[djalltra]

Hi can I use this library to connect to peripheral devices like esp32 and other ble related devices

 

[Erel]

This library allows you to implement the peripheral side. If you are connecting to a different peripheral (which is usually the case) then you need to implement the central side and it is done with this library: [B4X] BLE 2 - Bluetooth Low Energy

 

[djalltra]

ok thanks but i'm having issue with the reading and writing using ble2 as regards to reading and writing asynchronously when i usually write the reading freezes

 

[Erel]

ok thanks but i'm having issue with the reading and writing using ble2 as regards to reading and writing asynchronously when i usually write the reading freezes

It has nothing to do with this thread. Start a new one and provide more information.

 

[djalltra]

ok thanks ill do that