pub package


FlutterBlue



Introduction

FlutterBlue is a bluetooth plugin for Flutter, a new mobile SDK to help developers build modern apps for iOS and Android.

Alpha version

This library is actively developed alongside production apps, and the API will evolve as we continue our way to version 1.0.

Please be fully prepared to deal with breaking changes.

Having trouble adapting to the latest API? I'd love to hear your use-case, please contact me.

Cross-Platform Bluetooth LE

FlutterBlue aims to offer the most from both platforms (iOS and Android).

Using the FlutterBlue instance, you can scan for and connect to nearby devices (BluetoothDevice). Once connected to a device, the BluetoothDevice object can discover services (BluetoothService), characteristics (BluetoothCharacteristic), and descriptors (BluetoothDescriptor). The BluetoothDevice object is then used to directly interact with characteristics and descriptors.

Usage

Obtain an instance

FlutterBlue flutterBlue = FlutterBlue.instance;

Scan for devices

/// Start scanning
var scanSubscription = flutterBlue.scan().listen((scanResult) {
    // do something with scan result
    device = scanResult.device;
    print('${device.name} found! rssi: ${scanResult.rssi}');
});

/// Stop scanning
scanSubscription.cancel();

Connect to a device

/// Connect to the device
await device.connect();

/// Disconnect from device
device.disconnect();

Discover services

List<BluetoothService> services = await device.discoverServices();
services.forEach((service) {
    // do something with service
});

Read and write characteristics

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

// Writes to a characteristic
await c.write([0x12, 0x34])

Read and write descriptors

// Reads all descriptors
var descriptors = characteristic.descriptors;
for(BluetoothDescriptor d in descriptors) {
    List<int> value = await d.read();
    print(value);
}

// Writes to a descriptor
await d.write([0x12, 0x34])

Set notifications and listen to changes

await characteristic.setNotifyValue(true);
characteristic.value.listen((value) {
    // do something with new value
});

Reference

FlutterBlue API

AndroidiOSDescription
scanStarts a scan for Bluetooth Low Energy devices.
stateGets the current state of the Bluetooth Adapter.
onStateChangedStream of state changes for the Bluetooth Adapter.

BluetoothDevice API

AndroidiOSDescription
connectEstablishes a connection to the device.
disconnectCancels an active or pending connection to the device.
discoverServicesDiscovers services offered by the remote device as well as their characteristics and descriptors.
servicesGets a list of services. Requires that discoverServices() has completed.
stateGets the current state of the device.
onStateChangedNotifies of state changes for the device.

BluetoothCharacteristic API

AndroidiOSDescription
readRetrieves the value of the characteristic.
writeWrites the value of the characteristic.
setNotifyValueSets notifications or indications on the characteristic.
valueStream of characteristic's value when changed.

BluetoothDescriptor API

AndroidiOSDescription
readRetrieves the value of the descriptor.
writeWrites the value of the descriptor.

Troubleshooting

Scanning for service UUID's doesn't return any results

Make sure the device is advertising which service UUID's it supports. This is found in the advertisement packet as UUID 16 bit complete list or UUID 128 bit complete list.

Libraries

flutter_blue
flutterblue.pb
flutterblue.pbenum
flutterblue.pbjson
flutterblue.pbserver