Simple help

[MosheMendel18]

I could use some help just doing a simple read and write. I'm not sure how to get the serviceId characteristicId, BleInputProperty, or BleOutputProperty to run the code in the docs. Here's what I tried. It runs without error and manages to connect, but I don't know how to see any of the data from any devices. I think the beginning and end are fine, feel free to skip to the area between the asterisks.

void _scanBLE() async
  {
      var scanResult = await Permission.bluetoothScan.request();
      var connRes = await Permission.bluetoothConnect.request();
      if (scanResult == PermissionStatus.granted && connRes == PermissionStatus.granted) {
        setState(() {
          QuickBlue.startScan();
          QuickBlue.scanResultStream.listen((scanResult) {
            print('onScanResult ok ${scanResult.name}');
            QuickBlue.connect(scanResult.deviceId);
            void _handleConnectionChange(String deviceId, BlueConnectionState state) {
              print('_handleConnectionChange $deviceId, $state');
            }
            QuickBlue.setConnectionHandler(_handleConnectionChange);
//**********************************************************************************************************
//**********************************************************************************************************
//**********************************************************************************************************
// In order to get the values for serviceId and characteristicId, I just tried nesting value change, write, and read. I'm sure it's wrong.
            void _handleServiceDiscovery(String deviceId, String serviceId) { 
              print('_handleServiceDiscovery $deviceId, $serviceId');
                    void _handleValueChange(String deviceId, String characteristicId, Uint8List value) {
                      print('_handleValueChange $deviceId, $characteristicId, ${hex.encode(value)}');
                      QuickBlue.setNotifiable(scanResult.deviceId, serviceId, characteristicId, true as BleInputProperty);
                      List<int> list = 'Hello'.codeUnits; // random value for Uint8List, obviously can't be expected to set the value here
                      Uint8List bytes = Uint8List.fromList(list); 
                      QuickBlue.writeValue(deviceId, serviceId, characteristicId, bytes, true as BleOutputProperty); // just casted this to get it to work, but I'm sure it's wrong
                      QuickBlue.readValue(deviceId, serviceId, characteristicId);
                      QuickBlue.setNotifiable(deviceId, serviceId, characteristicId, true as BleInputProperty); // just casted this to get it to work, but I'm sure it's wrong
                    }
              QuickBlue.setValueHandler(_handleValueChange);
            }
            QuickBlue.setServiceHandler(_handleServiceDiscovery);
            QuickBlue.discoverServices(scanResult.deviceId);
            sleep(Duration(seconds: 3));
            QuickBlue.disconnect(scanResult.deviceId);
          });
//**********************************************************************************************************
//**********************************************************************************************************
//**********************************************************************************************************
          sleep(Duration(seconds: 4)); 
        QuickBlue.stopScan();
        });
      } else {
        if(scanResult == PermissionStatus.permanentlyDenied || connRes == PermissionStatus.permanentlyDenied) {
        openAppSettings();
      }
      }
  }

I expect the main issues are between the asterisk lines. I've tried to query things, but it seems like all the methods are void, and setting global variables didn't seem to work. Any help would be appreciated.

[SahilSharma2710]

Hey @MosheMendel18 , when we call QuickBlue.discoverServices(deviceId); it give us the list of all the services and their characteristics list of a particular device . You can use these serviceId characteristicId to use the any read or write operations

[MosheMendel18]

Hey @MosheMendel18 , when we call QuickBlue.discoverServices(deviceId); it give us the list of all the services and their characteristics list of a particular device . You can use these serviceId characteristicId to use the any read or write operations

Thanks for the reply, @SahilSharma2710. Would you be able to explain this a little more for me? Where do those values get saved so that I can call them in another command? (From what I can tell, it's a void method.)

For example, if I do this:

            QuickBlue.discoverServices(scanResult.deviceId);
            QuickBlue.readValue(scanResult.deviceId,serviceId,characteristicId); 

The editor shows errors under serviceId and characteristicId, so I can't run the program.