Bluetooth Low Energy (BLE) library

bioident said:

The same problem.
Only search.
But without connect and read charateristic

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Erel said:

What is the output of Log("Services = " & Services)?

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Erel said:

Call it before you call manager.ReadCharacteristic (which throws an error if I understand correctly).

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merlin2049er said:

hmm, still. The characteristics property type are of type [notify]. I can't read them (that's why it's returning false).

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Erel said:

Android 4.3 adds support for Bluetooth Low Energy. This library allows you to access the new API. It allows you to search for BLE devices, connect to a device and read its services and characteristics.

Writing is currently not supported though it should be simple to add this feature.

From my testings BLE is not yet ready for production
It is unreliable. I also tested it with Google example app and the results were the same.

Seems like others have encountered such issues as well:
http://code.google.com/p/android/issues/detail?id=58381
http://stackoverflow.com/questions/17870189/android-4-3-bluetooth-low-energy-unstable


In order to use this library you will need to download platform level 18 from Android SDK and configure the IDE (Tools - Configure Paths) to use it.

Simple code that starts searching when you click on the activity:

B4X:

Sub Process_Globals
   Dim manager As BleManager
   Private cs As List
End Sub

Sub Globals
   'These global variables will be redeclared each time the activity is created.
   'These variables can only be accessed from this module.

End Sub

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
     manager.Initialize("ble")
     Log("Supported: " & manager.BleSupported)
   End If
End Sub
Sub Activity_Click
   Log("Searching for devices")
   manager.Scan(10000, Null)
End Sub
Sub ble_DeviceFound (Name As String, MacAddress As String)
   Log(Name & ", " & MacAddress)
   manager.Connect(MacAddress, True)
End Sub

Sub BLE_Connected (Services As Map)
   cs.Initialize
   Dim s As BleService = Services.GetValueAt(0)
'Read the manufacturer characteristic
   Dim c As BleCharacteristic = s.GetCharacteristics.Get("00002a00-0000-1000-8000-00805f9b34fb")
   manager.ReadCharacteristic(c)
End Sub

Sub BLE_CharacteristicRead (Success As Boolean, Characteristic As BleCharacteristic)
   Log("CR: " & Success & ": " & Characteristic.Uuid)
   If Success Then Log("cr: " & Characteristic.GetStringValue(0)) 
End Sub
Sub ble_Disconnected
   Log("Disconnected")
End Sub

Sub ble_DiscoveryFinished
   Log("DiscoveryFinished")
End Sub

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** Activity (main) Create, isFirst = true **
Supported: true
** Activity (main) Resume **
Searching for devices
Beurer GL50EVO, F4:04:4C:0C6:58
Discovering services.
services map size: 5
00001800-0000-1000-8000-00805f9b34fb android.bluetooth.BluetoothGattService@3bcefae6
00001801-0000-1000-8000-00805f9b34fb android.bluetooth.BluetoothGattService@3b771827
0000180a-0000-1000-8000-00805f9b34fb android.bluetooth.BluetoothGattService@303b5ad4
00001808-0000-1000-8000-00805f9b34fb android.bluetooth.BluetoothGattService@32ea747d
0000fff0-0000-1000-8000-00805f9b34fb android.bluetooth.BluetoothGattService@32ffdf72
s: (BluetoothGattService) android.bluetooth.BluetoothGattService@3bcefae6
main_timer1_tick (B4A line: 109)
manager.ReadCharacteristic(c)
java.lang.RuntimeException: Object should first be initialized (BleCharacteristic).
at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:50)
at anywheresoftware.b4a.objects.BleManager.ReadCharacteristic(BleManager.java:142)
at com.genesis.evo.main._timer1_tick(main.java:608)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:187)
at anywheresoftware.b4a.objects.Timer$TickTack.run(Timer.java:105)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5297)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
java.lang.RuntimeException: Object should first be initialized (BleCharacteristic).

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manager.ReadCharacteristic(c)

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
   Dim manager As BleManager
   Private cs As List
   Dim timer1 As Timer
   Dim map1 As Map
    Dim c As BleCharacteristic
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")
   
    If FirstTime Then
     manager.Initialize("ble")
     Log("Supported: " & manager.BleSupported)
   End If
  
   timer1.Initialize("timer1", 1000)

End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub Activity_Click
   Log("Searching for devices")
   manager.Scan(10000, Null)
End Sub
Sub ble_DeviceFound (Name As String, MacAddress As String)
   Log(Name & ", " & MacAddress)
   manager.Connect(MacAddress, True)
End Sub

Sub BLE_Connected (Services As Map)
   cs.Initialize
   Log("services map size: " & Services.Size)
  
   map1 = Services
  
   For i = 0 To Services.Size - 1
       Log(Services.GetKeyAt(i) & " " & Services.GetValueAt(i))
   Next
  
   Dim s As BleService = Services.GetValueAt(0)

'get the glucose readings
  c = s.GetCharacteristics.Get("00001800-0000-1000-8000-00805f9b34fb")
   timer1.Enabled = True 
End Sub

Sub BLE_CharacteristicRead (Success As Boolean, Characteristic As BleCharacteristic)
   Log("CR: " & Success & ": " & Characteristic.Uuid)
   If Success Then
   Log("cr0: " & Characteristic.GetStringValue(0)) 
   End If
End Sub
Sub ble_Disconnected
   Log("Disconnected")
End Sub

Sub ble_DiscoveryFinished
   Log("DiscoveryFinished")
End Sub

Sub timer1_Tick
   manager.ReadCharacteristic(c)
   timer1.Enabled = False
End Sub

Erel said:

Start with this post: https://www.b4x.com/android/forum/threads/get-values-from-device-using-ble.57758/#post-363602

If it doesn't help then please start a new thread (and post the result of that code).

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