CODEWITHSUNDEEP
flutterbluetooth-lowenergy
devlade
devlade

Reputation: 21

Flutter Blue Read Characteristics on Successful Connect

How do I listen to the response from my Arduino device on a successful connection?

Once connected, my Arduino devices send a list of values in this format [1111111111111111111111111111111111234].

But When I used Flutter Blue Package to read the characteristics, I was getting values like [45, 27, 8, 9], [0, 0], [0], [80, 45, 0, 2, 40]. When I converted these values with Utf8Decoder, it returned the name of the Bluetooth Device to me.

Below is my code I have tried

void dataReceived(Uint8List data){
if (data != null && data.length > 0) {

  updatedValue.add(data);
  print('data received $updatedValue');

  if (finalData.isNotEmpty) finalData.clear();
  print('final Data Empty $finalData');
}

print(' updated value: $updatedValue');

for (var i = 0; i < updatedValue.length; i++) {
  for (var j = 0; j < updatedValue[i].length; j++) {
    finalData.add(updatedValue[i][j]);
  }
}

print('final data $finalData');

String signals = Utf8Decoder().convert(finalData);

String binary = converter.toBinary(signals);
print("Binary: $binary");

print('signals: $signals');

    }

NOTE: I have used BLUETOOTH SERIAL TO CONNECT AND IT GIVES ME CORRECT VALUES ARDUINO SENDS AFTER CONNECTION, BUT I'M NOW USING FLUTTER BLUE BECAUSE OF COMPATIBILITY WITH IOS

I need the correct values/signals that arduino sends after connection with flutter blue package, suggestion and code on how to do this, I have been on it for days now.

Upvotes: 1

Views: 3895

Answers (3)

ARCHER
ARCHER

Reputation: 124

this might help you in sucessfull connection https://github.com/edufolly/flutter_bluetooth_serial/blob/master/README.md

Demo Code

try {
    BluetoothConnection connection = await BluetoothConnection.toAddress(address);
    print('Connected to the device');

    connection.input.listen((Uint8List data) {
        print('Data incoming: ${ascii.decode(data)}');
        connection.output.add(data); // Sending data

        if (ascii.decode(data).contains('!')) {
            connection.finish(); // Closing connection
            print('Disconnecting by local host');
        }
    }).onDone(() {
        print('Disconnected by remote request');
    });
}
catch (exception) {
    print('Cannot connect, exception occured');
}

Upvotes: 0

adadion
adadion

Reputation: 786

Piece of code from the flow I use when using Flutter Blue after succesfully connected:

  1. After connected (snapshot.data == BluetoothDeviceState.connected)
  2. Discover available services and characteristics from the connected device, something like
    BluetoothService mGattService;
    List<BluetoothService> gattServices;
    List<BluetoothCharacteristic> gattCharacteristics;
    String notifValue;

--------------------------------------------------------------

    // aftter connected
    gattServices = await widget.device.discoverServices();
    gattServices.forEach((service) {
      Guid currentServiceUid = service.uuid;

      mGattService = service;
        gattCharacteristics = mGattService.characteristics;
        gattCharacteristics.read().then((value) {
        notifValue = value.toString();
        print('Value from arduino = $notifValue');
      });

Upvotes: 0

Kaushik Chandru
Kaushik Chandru

Reputation: 17762

I think the values that you are receiving from flutter_blue are a list of int. which can be converted to string using String.fromCharCodes

List<int> response = const [34, 35, 36];
print(String.fromCharCodes(response));

After you read connect to the device try this code

var characteristics = service.characteristics;
for(BluetoothCharacteristic c in characteristics) {
    List<int> value = await c.read();
    print(value);
}

Upvotes: 1

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