120 lines
5.1 KiB
Markdown
120 lines
5.1 KiB
Markdown
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[](https://pub.dartlang.org/packages/flutter_blue)
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<br>
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<p align="center">
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<img alt="FlutterBlue" src="https://github.com/pauldemarco/flutter_blue/blob/master/site/flutterblue.png?raw=true" />
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</p>
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<br><br>
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## Introduction
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FlutterBlue is a bluetooth plugin for [Flutter](http://www.flutter.io), a new mobile SDK to help developers build modern apps for iOS and Android.
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## Cross-Platform Bluetooth LE
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FlutterBlue aims to offer the most from both platforms (iOS and Android).
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Using the FlutterBlue instance, you can scan for and connect to nearby devices ([BluetoothDevice](#bluetoothdevice-api)).
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Once connected to a device, the BluetoothDevice object can discover services ([BluetoothService](lib/src/bluetooth_service.dart)), characteristics ([BluetoothCharacteristic](lib/src/bluetooth_characteristic.dart)), and descriptors ([BluetoothDescriptor](lib/src/bluetooth_descriptor.dart)).
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The BluetoothDevice object is then used to directly interact with characteristics and descriptors.
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## Usage
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### Obtain an instance
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```dart
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FlutterBlue flutterBlue = FlutterBlue.instance;
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```
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### Scan for devices
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```dart
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/// Start scanning
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var scanSubscription = flutterBlue.scan().listen((scanResult) {
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// do something with scan result
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});
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/// Stop scanning
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scanSubscription.cancel();
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```
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### Connect to a device
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```dart
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/// Create a connection to the device
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var deviceConnection = flutterBlue.connect(device).listen((s) {
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if(s == BluetoothDeviceState.connected) {
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// device is connected, do something
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}
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});
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/// Disconnect from device
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deviceConnection.cancel();
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```
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### Discover services
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```dart
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List<BluetoothService> services = await device.discoverServices();
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services.forEach((service) {
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// do something with service
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});
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```
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### Read and write characteristics
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```dart
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// Reads all characteristics
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var characteristics = service.characteristics;
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for(BluetoothCharacteristic c in characteristics) {
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List<int> value = await device.readCharacteristic(c);
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print(value);
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}
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// Writes to a characteristic
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await device.writeCharacteristic(c, [0x12, 0x34])
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```
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### Read and write descriptors
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```dart
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// Reads all descriptors
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var descriptors = characteristic.descriptors;
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for(BluetoothDescriptor d in descriptors) {
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List<int> value = await device.readDescriptor(d);
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print(value);
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}
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// Writes to a descriptor
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await device.writeDescriptor(d, [0x12, 0x34])
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```
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### Set notifications
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```dart
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await device.setNotifyValue(characteristic, true);
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device.onValueChanged(characteristic).listen((value) {
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// do something with new value
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});
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```
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## Reference
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### FlutterBlue API
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| | Android | iOS | Description |
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| :--------------- | :----------------: | :------------------: | :-------------------------------- |
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| scan | :white_check_mark: | :white_check_mark: | Starts a scan for Bluetooth Low Energy devices. |
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| connect | :white_check_mark: | :white_check_mark: | Establishes a connection to the Bluetooth Device. |
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| state | :white_check_mark: | :white_check_mark: | Gets the current state of the Bluetooth Adapter. |
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| onStateChanged | :white_check_mark: | :white_check_mark: | Stream of state changes for the Bluetooth Adapter. |
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### BluetoothDevice API
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| | Android | iOS | Description |
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| :-------------------------- | :------------------: | :------------------: | :-------------------------------- |
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| discoverServices | :white_check_mark: | :white_check_mark: | Discovers services offered by the remote device as well as their characteristics and descriptors. |
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| services | :white_check_mark: | :white_check_mark: | Gets a list of services. Requires that discoverServices() has completed. |
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| readCharacteristic | :white_check_mark: | :white_check_mark: | Retrieves the value of a specified characteristic. |
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| readDescriptor | :white_check_mark: | :white_check_mark: | Retrieves the value of a specified descriptor. |
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| writeCharacteristic | :white_check_mark: | :white_check_mark: | Writes the value of a characteristic. |
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| writeDescriptor | :white_check_mark: | :white_check_mark: | Writes the value of a descriptor. |
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| setNotifyValue | :white_check_mark: | :white_check_mark: | Sets notifications or indications on the specified characteristic. |
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| onValueChanged | :white_check_mark: | :white_check_mark: | Notifies when the characteristic's value has changed. |
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| state | :white_check_mark: | :white_check_mark: | Gets the current state of the Bluetooth Device. |
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| onStateChanged | :white_check_mark: | :white_check_mark: | Notifies of state changes for the Bluetooth Device. |
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## Troubleshooting
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### Scanning for service UUID's doesn't return any results
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Make sure the device is advertising which service UUID's it supports. This is found in the advertisement
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packet as **UUID 16 bit complete list** or **UUID 128 bit complete list**.
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