jBluetooth: how to use
lazarus / 43-Android

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svd71 · 2020-06-11 18:16

Hallo all.

Can somebody explaine me how to work with a bluetooth-module like
HM-10? An example named as " AppBluetoothClientSocketHC0506Terminal1"
has compiled with errors and crashed after run on device.

I built an test-example. A smartphone find a target device by name,
but can't to connect with him and read/write a data from bt-module.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
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u_mainform; {$mode delphi} interface uses  {$IFDEF UNIX}{$IFDEF
UseCThreads}  cthreads,  {$ENDIF}{$ENDIF}  Classes, SysUtils,
AndroidWidget, Laz_And_Controls, bluetooth,  bluetoothclientsocket,
togglebutton;  type   { TAndroidModule1 }   TAndroidModule1 =
class(jForm)    jBluetooth1: jBluetooth;    jBluetoothClientSocket1:
jBluetoothClientSocket;    jDialogProgress_BT_Discovery:
jDialogProgress;    jTextView_BTDev: jTextView;   
jTimer_Bluetooth_chk: jTimer;    jToggleButton1: jToggleButton;   
procedure AndroidModule1CloseQuery(Sender: TObject; var CanClose:
boolean);    procedure AndroidModule1JNIPrompt(Sender: TObject);   
procedure AndroidModule1RequestPermissionResult(Sender: TObject;     
requestCode: integer; manifestPermission: string;      grantResult:
TManifestPermissionResult);    procedure
jBluetooth1DeviceFound(Sender: TObject; deviceName: string;     
deviceAddress: string);    procedure jBluetooth1Disabled(Sender:
TObject);    procedure jBluetooth1DiscoveryFinished(Sender: TObject; 
   countFoundedDevices: integer; countPairedDevices: integer);   
procedure jBluetooth1DiscoveryStarted(Sender: TObject);    procedure
jBluetooth1Enabled(Sender: TObject);    procedure
jBluetoothClientSocket1Connected(Sender: TObject;      deviceName:
string; deviceAddress: string);    procedure
jBluetoothClientSocket1Disconnected(Sender: TObject);    procedure
jBluetoothClientSocket1IncomingData(Sender: TObject;      var
dataContent: TDynArrayOfJByte; dataHeader: TDynArrayOfJByte);   
procedure jTimer_Bluetooth_chkTimer(Sender: TObject);    procedure
jToggleButton1Toggle(Sender: TObject; state: boolean);  private   
{private declarations}  public    FIsDiscovering: boolean;   
procedure ShowNewDevices;    procedure Discovery_BT;    procedure
Disable_BT;    procedure ShowPairedDevices;    procedure
BindDevice(const deviceName, deviceAddress: String);  end; var 
AndroidModule1: TAndroidModule1;  test_send_msg_count: integer; 
receive_msg_str: string;  jTimer_Bluetooth_chk_count: integer; 
toast_bt_rx_en: boolean; implementation  {$R *.lfm}   {
TAndroidModule1 } procedure
TAndroidModule1.AndroidModule1JNIPrompt(Sender: TObject);var 
BT_device: string;begin   if IsRuntimePermissionNeed() then   // that
is, if target API >= 23  begin    ShowMessage('Requesting Runtime
Permission....');    Self.RequestRuntimePermission(['android.permissio
n.ACCESS_COARSE_LOCATION',                                 
 'android.permission.ACCESS_FINE_LOCATION'], 1110);   //handled by
OnRequestPermissionResult  end;   jTextView_BTDev.Text:= ''; 
Self.SetScreenOrientationStyle(ssPortrait); //Portrait orientation
only  toast_bt_rx_en := True; //Toast Bt RX enable by default  if (not
jBluetooth1.IsEnable()) then  begin    jBluetooth1.Enabled();//  
 jTimer_Bluetooth_chk.Interval := 1000; // 15 sec wait to turn on
Bluetooth module//    jTimer_Bluetooth_chk.Enabled := True;//  
 jTimer_Bluetooth_chk_count := 0;  end  else  begin    //Here when BT
already enabled on startup app    Discovery_BT;  end;  //
 ShowPairedDevices;end; procedure
TAndroidModule1.AndroidModule1CloseQuery(Sender: TObject;  var
CanClose: boolean);begin  if (jBluetoothClientSocket1.IsConnected())
then    jBluetoothClientSocket1.Disconnect();  CanClose :=
True;end; procedure
TAndroidModule1.AndroidModule1RequestPermissionResult(  Sender:
TObject; requestCode: integer; manifestPermission: string; 
grantResult: TManifestPermissionResult);begin  case requestCode of 
1110:begin         if grantResult = PERMISSION_GRANTED  then       
 begin            //if manifestPermission =
'android.permission.ACCESS_COARSE_LOCATION' then
ShowMessage('"'+manifestPermission+'"  granted!');            //if
manifestPermission = 'android.permission.ACCESS_FINE_LOCATION' then
ShowMessage('"'+manifestPermission+'"  granted!')         end       
else//PERMISSION_DENIED        begin            ShowMessage('Sorry...
"['+manifestPermission+']" not granted... ' );        end;     end; 
end;end; procedure TAndroidModule1.jBluetooth1DeviceFound(Sender:
TObject;  deviceName: string; deviceAddress: string);begin  if
(deviceName = 'CARDI0') then  begin    //ShowMessage('deviceName: '
+deviceName +' : deviceAddress: '+deviceAddress);   
//jListView1.Add(deviceName + '|' + deviceAddress);   
jTextView_BTDev.Text := deviceName + ':' + deviceAddress;   
BindDevice(deviceName, deviceAddress);  end;end; procedure
TAndroidModule1.jBluetooth1Disabled(Sender: TObject);begin 
jTextView_BTDev.Text := '';  jToggleButton1.State:= tsOn; 
ShowMessage('Bluetooth Off');end; procedure
TAndroidModule1.jBluetooth1DiscoveryFinished(Sender: TObject; 
countFoundedDevices: integer; countPairedDevices: integer);begin 
jDialogProgress_BT_Discovery.Stop;  FIsDiscovering := False; 
//ShowNewDevices();end; procedure
TAndroidModule1.jBluetooth1DiscoveryStarted(Sender: TObject);begin 
FIsDiscovering := True;  ShowMessage('Starting Discovering News
Devices..');end; procedure TAndroidModule1.jBluetooth1Enabled(Sender:
TObject);begin  if (jBluetooth1.IsEnable()) then  begin   
ShowMessage('Bluetooth On');    jTimer_Bluetooth_chk.Enabled :=
False;  end;end; procedure
TAndroidModule1.jBluetoothClientSocket1Connected(Sender: TObject; 
deviceName: string; deviceAddress: string);begin 
 ShowMessage('connected');   jToggleButton1.State:=
tsOff;end; procedure
TAndroidModule1.jBluetoothClientSocket1Disconnected(Sender:
TObject);begin  ShowMessage('Disconnected');  jToggleButton1.State:=
tsOn;end; procedure
TAndroidModule1.jBluetoothClientSocket1IncomingData(Sender: TObject; 
var dataContent: TDynArrayOfJByte; dataHeader:
TDynArrayOfJByte);begin 
ShowMessage(jBluetoothClientSocket1.JByteArrayToString(dataContent)); 
jTextView_BTDev.Text:= jBluetoothClientSocket1.JByteArrayToString(data
Content);end;  procedure
TAndroidModule1.jTimer_Bluetooth_chkTimer(Sender: TObject);begin 
//Check after 30 sec Android module Bluetooth is enabled, if not close
app  Inc(jTimer_Bluetooth_chk_count); // + 1 sec  if
(jTimer_Bluetooth_chk_count > 30) then  begin   
jTimer_Bluetooth_chk.Enabled := False;    //30 sec elapsed, check BT
is enabled    if (not jBluetooth1.IsEnable()) then    begin     
AndroidModule1.Close;    end    else    begin     
ShowMessage('Bluetooth On');      Discovery_BT;    end;  end  else 
begin    //30 sec not elapsed, check BT is enabled    if
(jBluetooth1.IsEnable()) then    begin     
jTimer_Bluetooth_chk.Enabled := False;      ShowMessage('Bluetooth
On');      Discovery_BT;    end;  end;end; procedure
TAndroidModule1.jToggleButton1Toggle(Sender: TObject; state:
boolean);begin  if not state then    Discovery_BT  else   
Disable_BT;end; procedure TAndroidModule1.ShowNewDevices;var 
listArray: TDynArrayOfString;  i, size: integer;begin  listArray :=
jBluetooth1.GetFoundedDevices();  if listArray <> nil then  begin   
size := Length(listArray);    if size = 0 then      ShowMessage('News
Devices Not Found ... [0]')    else    begin      if
(listArray[0].Contains('null')) then      begin       
ShowMessage('News Devices Not Found ... empty');      end      else  
  begin        //jListView1.Clear;        //jListView_BT_connect.Add('
     Select a Bluetooth Server:');//        jTextView_BT_list.Text :=
'Bluetooth Device: [Discovered]';        for i := 0 to size - 1 do   
   begin          //ShowMessage(listArray[i]);         
//jListView1.Add(listArray[i]);        end;       
SetLength(listArray, 0);      end;    end;  end  else   
ShowMessage('News Devices Not Found ... [nil]');end; procedure
TAndroidModule1.Discovery_BT;begin   if not IsRuntimePermissionGranted
('android.permission.ACCESS_COARSE_LOCATION') then  begin   
ShowMessage('Sorry... "android.permission.ACCESS_COARSE_LOCATION');  
Exit;  end;   if not
IsRuntimePermissionGranted('android.permission.ACCESS_FINE_LOCATION')
then  begin    ShowMessage('Sorry...
"android.permission.ACCESS_FINE_LOCATION');    Exit;  end;   if not
jBluetooth1.IsEnable() then    jBluetooth1.Enabled();  if
(jBluetooth1.IsEnable()) then  begin    //Discovery BT devices//  
 jListView_BT_connect.Clear;    jBluetooth1.Discovery();    //handled
by: OnDiscoveryStarted, OnDeviceFound and OnDiscoveryFinished//  
 jDialogProgress_BT_Discovery.Show();  end  else   
jToggleButton1.State := tsOn;end; procedure
TAndroidModule1.Disable_BT;begin  jBluetooth1.Disable(); 
jTextView_BTDev.Text := '';end; procedure
TAndroidModule1.ShowPairedDevices;var  listArray: TDynArrayOfString; 
i, size: integer;begin  listArray :=
jBluetooth1.GetReachablePairedDevices();  if listArray <> nil then 
begin    size := Length(listArray);    if size = 0 then     
ShowMessage('Paired Devices Not Found ... [0]')    else    begin     
if (listArray[0].Contains('null')) then      begin       
ShowMessage('Paired Devices Not Found ... empty');      end      else 
    begin        //jListView1.Clear;       
//jListView_BT_connect.Add('      [Paired] Select a Bluetooth
Server'); //       jTextView_BT_list.Text := 'Bluetooth Device:
[Paired]';        for i := 0 to size - 1 do        begin         
//ShowMessage(listArray[i]);          //jListView1.Add(listArray[i]); 
      end;        SetLength(listArray, 0); //free ...      end;   
end;  end  else    ShowMessage('Paired Devices Not Found ...
[nil]');end; procedure TAndroidModule1.BindDevice(const deviceName,
deviceAddress: String);begin  if Pos('null', deviceAddress) <= 0 then 
begin    if  jBluetooth1.IsReachablePairedDevice(deviceAddress) then 
 begin      jBluetoothClientSocket1.SetDevice(       
jBluetooth1.GetReachablePairedDeviceByAddress(deviceAddress));     
//well known SPP UUID      jBluetoothClientSocket1.SetUUID('00001101-
0000-1000-8000-00805F9B34FB');      //default     
jBluetoothClientSocket1.Connect();     end    else    begin     
ShowMessage('Try to pair device...');     
jBluetooth1.PairDeviceByAddress(deviceAddress);     
//ShowMessage('Not ReachablePairedDevice...');    end; 
end; end; end  

Thank you for any advise.