Quick Xamarin BLE

quick access Bluetooth Low Energy on xamarin Forms Android and IOS

Limitations

Platform	Version
xamarin.forms
xamarin.android	API LEVEL>=18
xamarin.ios	ios SDK>=7

Installation

NuGet

Install-Package Quick.Xamarin.BLE -Version 1.0.4

Sample

Simple bluetooth search example. created by xamarin.forms

key features include

1. Scan Bluetooth
2. List Bluetooth addresses
3. Bluetooth connect/disconnect
4. Search service and characteristic
5. List characteristic features
6. Read/Write/Notify

Permission

Android AndroidManifest add permission

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

Start

Initialization

IBle ble = CrossBle.Createble(); 

Scan Bluetooth

 ble.OnScanDevicesIn += (sender, device) =>
 {
     Device.BeginInvokeOnMainThread(() =>
     { 
          //use device.Name or Uuid or Rssi or connect dev
          IDev dev=device;
     });
 };
 //start scan
 ble.StartScanningForDevices();

Stop scan

 ble.StopScanningForDevices();

Device connect

 dev.ConnectToDevice();

Device disconnect

dev.DisconnectDevice();

Bluetooth device Status callback event

 ble.AdapterStatusChange += (sender,Status) =>
 {
	 Device.BeginInvokeOnMainThread(() =>
     { 
		 if (Status == AdapterConnectStatus.Connected)//Connect
		 if (Status == AdapterConnectStatus.None)//disconnect
     });
 };

Get device characteristics

  List<IGattCharacteristic> cha= new List<IGattCharacteristic>();
 dev.CharacteristicsDiscovered(value=>
 {  
     Device.BeginInvokeOnMainThread(() =>
     {   
	     //save value to list and use
	     cha.Add(chvaluea); 
     });
 });

Get characteristics properties

cha[n].CanRead();
cha[n].CanWrite();
cha[n].CanNotify();

Read

//Call once
Search.ble.ServerCallBackEvent += (uuid, value) => 
{

};

cha[n].ReadCallBack();

or

var value=await cha[n].ReadCallBack();

Write

  cha[n].Write(byte[]);

Notify

 cha[n].NotifyEvent += SelectCharacteristic_NotifyEvent;
 cha[n].Notify();

Stop Notify

enter code here
 cha[n].StopNotify();
 cha[n].NotifyEvent -= SelectCharacteristic_NotifyEvent;

Notify Event

 private void SelectCharacteristic_NotifyEvent(object sender, byte[] value)
 {
     Device.BeginInvokeOnMainThread(() => { 
     });
 }

Important limitations

• Event must be added Device.BeginInvokeOnMainThread
• Characteristicsmust be 1-2 seconds after the Bluetooth connection
• Bluetooth can only connect one at a time,When you want to connect other,Must call DisconnectDevice() first