PDJ

Hello, I have written an app for Android using Bluetooth LE to communicate with a ESP32. Everything works fine, I have set up an encrypted BLE connection, I can send and receive data, however TBluetoothLEDevice.Paired is always false, even after a successful pair it's still false, I need this because I want to write something after the application has been started, for a bonded device, I can send it right away after subscription to the Characteristic service, but if the device has not been paired, Android wants to pair first and the app is sending unencrypted data to the other device and gets ignored. Here some parts of the code procedure TMyForm.Button1Click(Sender: TObject); var ABLEAdvertisedDataFilter: TBluetoothLEScanFilter; ABLEAdvertisedDataFilterList: TBluetoothLEScanFilterList; const permBatt = 'android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS'; permRead = 'android.permission.READ_EXTERNAL_STORAGE'; permWrite = 'android.permission.WRITE_EXTERNAL_STORAGE'; permBlue = 'android.permission.BLUETOOTH'; permAccess = 'android.permission.ACCESS_FINE_LOCATION'; permCoarse = 'android.permission.ACCESS_COARSE_LOCATION'; begin {$IFDEF ANDROID} PermissionsService.RequestPermissions([permBatt,permRead, permWrite, permBlue, permAccess, permCoarse], procedure(const APermissions: TClassicStringDynArray; const AGrantResults: TClassicPermissionStatusDynArray) begin // Some code to do for permissions end); {$ENDIF} ABLEAdvertisedDataFilter:= TBluetoothLEScanFilter.Create; ABLEAdvertisedDataFilterList:= TBluetoothLEScanFilterList.Create; ABLEAdvertisedDataFilter.ServiceUUID:= MyBLEServiceID; ABLEAdvertisedDataFilterList.Add(ABLEAdvertisedDataFilter); //ListBox1.Items.Add('Start Discover'); BluetoothLE1.DiscoverDevices(2000,ABLEAdvertisedDataFilterList); end; procedure TMyForm.BluetoothLE1EndDiscoverDevices(const Sender: TObject; const ADeviceList: TBluetoothLEDeviceList); begin if ADeviceList.Count > 0 then begin CaravanBT := BluetoothLE1.DiscoveredDevices.First; CaravanBT.Connect; end; end; procedure TTabbedForm.BluetoothLE1Connect(Sender: TObject); begin BTConnectServices; end; procedure TMyForm.CaravanBTConnectServices(); begin CaravanBT.DiscoverServices; if BluetoothLE1.GetServices(CaravanBT).Count > 0 then begin CaravanBTGatt := nil; CaravanBTGattCharact := nil; CaravanBTGatt := BluetoothLE1.GetService(CaravanBT,CaravanBLEServiceID); if CaravanBTGatt <> nil then begin // got the service CaravanBTGatt.Characteristics; CaravanBTGattCharact := BluetoothLE1.GetCharacteristic(CaravanBTGatt,CaravanBLECHarID); if CaravanBTGattCharact <> nil then begin BluetoothLE1.SubscribeToCharacteristic(CaravanBT, CaravanBTGattCharact); BTFullyConnected := True; // HERE I CAN SEND SOME DATA, BUT ONLY WHEN THE DEVICE HAS BEEN BONDED BTSendTimer.Enabled := True; end; end else begin // No services found {$IFDEF ANDROID} Toast('No services found',2000); {$ENDIF} end; end; end; procedure TMyForm.BTSendTimerTimer(Sender: TObject); begin if (CaravanBT.Paired = true) then begin BTSendTimer.Enabled := False; // SEND SOMETHING end else begin // Not Paired // ALWAYS end; end;

Thank you for the reply. This is the Delphi code that runs on Android. Pairing and bonding works fine, on both ends (Android and ESP32) , I can send data back and forth, but on the Android side CaravanBT.Paired stay false, even after a successful pairing. P.S. Adding android.permission.BLUETOOTH_ADMIN did not help