B4R Question Weird behavior with HC-05 and B4A....

[Yayou49]

Hi,

Trying to test a HC-05 with a nano, I'm facing an issue.
I have a code working very well as follow:
(code linked with BluetoothManager)

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("init")
    connection
End Sub

Sub Activity_Resume
End Sub

Sub Activity_Pause (UserClosed As Boolean)
    If UserClosed Then
        Starter.Manager.Disconnect
    End If
End Sub

public Sub connection
    Dim device As NameAndMac
    device.Name = "HC-05"
    device.Mac = "AA:BB:CC:DD:EE:FF"
    Starter.Manager.ConnectTo(device)
    ProgressDialogShow2($"Trying to connect to: ${device.Name} (${device.Mac})"$, False)
End Sub

Public Sub AfterConnect (Success As Boolean)
    ProgressDialogHide
End Sub

Sub Bt1On_Click
    Starter.Manager.SendMessage("Hello")
End Sub

Now, my problem is to release the connection to HC-05 when event is done.
Target is to allow multiple devices to access the same HC-05.
So I've change my code to start the connection on push button and release the connection after sending message:

Sub Globals
    Dim Message As String
End Sub

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("init")
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)
    If UserClosed Then
        Starter.Manager.Disconnect
    End If
End Sub


public Sub connection
    Dim device As NameAndMac
    device.Name = "HC-05"
    device.Mac = "AA:BB:CC:DD:EE:FF"
    Starter.Manager.ConnectTo(device)
    ProgressDialogShow2($"Trying to connect to: ${device.Name} (${device.Mac})"$, False)
End Sub

Public Sub AfterConnect (Success As Boolean)
    ProgressDialogHide

    If Success = True Then
            Send
    End If
End Sub

Sub Send
    
    Starter.Manager.SendMessage(Message)
    Starter.Manager.Disconnect
    
End Sub

Sub Bt1On_Click
    connection
    Message = "Hello"
End Sub

With this code, message is not received by HC-05 and app crash.
What do I miss ?

Thanks in advance for your help.

 

[Erel]

Is this a B4A or B4R question? What is the error message?

 

[Yayou49]

Is this a B4A or B4R question? What is the error message?

I was asking myself a long time to know if it's a B4R or B4A question ....
I don't know if it is relevant of one of them especially.

BTW, there is no error message.
text sent to the HC-05 is not received and app fully crash without error message.

I know this is poor as information.

Do you think it can be better to add a callsub at the end of Starter.Manager.SendMessage to call a sub that close the connection only when message is send ?

 

[Erel]

There must be an error message in the logs when the app crashes.

 

[Yayou49]

sorry for the late, I was out.

Error message is:

connected: true
bluetoothmanager_serial_connected (java line: 224)
java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.InputStream android.bluetooth.BluetoothSocket.getInputStream()' on a null object reference
at anywheresoftware.b4a.objects.Serial.getInputStream(Serial.java:254)
at rm.unlock.bluetoothmanager._serial_connected(bluetoothmanager.java:224)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:191)
at anywheresoftware.b4a.BA$2.run(BA.java:365)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6682)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)

 

[Erel]

 Starter.Manager.SendMessage(Message)
    Starter.Manager.Disconnect

The data is sent asynchronously. Add Sleep(500) before you disconnect.

 

[Yayou49]

Add Sleep(500) before you disconnect.

Yes, this solution will surely feet my goal.

BTW, calling the send message from "Public Sub AfterConnect", doesn't work.

Even if I call directly the Starter.Manager.SendMessage(Message) without calling "Send", BluetoothManager.sendMessage is raised but Arduino did not receive the message.

Adding a new button with Starter.Manager.SendMessage(Message) only, works perfectly.

So what can be the reason that calling sendMessage from "Public Sub AfterConnect" doesn't work ???

Thx in advance.

 

[Erel]

So what can be the reason that calling sendMessage from "Public Sub AfterConnect" doesn't work ???

Please start a new thread for a new question.