Android Bluetooth Low Energy devices listview

Question

I need to show all the bluetooth low energy devices on a listview so that when you click in one of those devices the phone should connect to that one. First of all I´m trying to show the devices, for that I have this activity:

package com.sma.javier.sma_q;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.bluetooth.le.BluetoothLeScanner;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanResult;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;

public class BTConnectActivity extends AppCompatActivity {

    private int REQUEST_ENABLE_BT = 1;
    ArrayList<String> listItems=new ArrayList<String>();
    ArrayAdapter<String> adapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_btconnect);

        final ListView devicesListView = (ListView)this.findViewById(R.id.devicesListView);
        final ArrayAdapter<BluetoothDevice> arrayAdapter = new ArrayAdapter<>(BTConnectActivity.this, android.R.layout.simple_list_item_1);
        devicesListView.setAdapter(arrayAdapter);

        BluetoothManager bm = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
        BluetoothAdapter mBluetoothAdapter = bm.getAdapter();

        // Ensures Bluetooth is available on the device and it is enabled. If not,
        // displays a dialog requesting user permission to enable Bluetooth.
        if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new Int

ent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
    }

    BluetoothLeScanner scanner = mBluetoothAdapter.getBluetoothLeScanner();
    scanner.startScan(new ScanCallback() {
        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            // get the discovered device as you wish
            // this will trigger each time a new device is found

            BluetoothDevice device = result.getDevice();
            arrayAdapter.add(device);
        }
    });
}
}

And the xml layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.sma.javier.sma_q.BTConnectActivity">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/devicesListView"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />
</RelativeLayout>

I also have the necessary permissions on the manifest, and I´m testing the app on android 6.0, but this doesn´t show anything. I have also tried with this example, but I don´t know to use it.

Add mBluetoothAdapter.enable() after BluetoothAdapter mBluetoothAdapter = bm.getAdapter(); — tiny sunlight, Jan 10 '16 at 12:16
Try adapter.startLeScan(new BluetoothAdapter.LeScanCallback() { @Override public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) { } }) — tiny sunlight, Jan 10 '16 at 12:23
But, how should I use it?? When I put it on Android Studio startLeScan is in red color — Javierd98, Jan 10 '16 at 12:34
Can you post a screenshot?And move mouse on it to get the error. — tiny sunlight, Jan 10 '16 at 14:47
mBluetoothAdapter.startLeScan(new BluetoothAdapter.LeScanCallback() { @Override public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) { } }) — tiny sunlight, Jan 11 '16 at 01:27
Does it ever call onScanResult? Can you ad Log to it and see if it ever starts scanning? In other saying,be sure if it is UI thing or BLE related problem. — ulusoyca, Jan 11 '16 at 08:06
It does not work with the new code neither. Here you have the logs:http://imgur.com/a/4B1gM — Javierd98, Jan 11 '16 at 21:49
@TusharGogna No, in fact I opened a new threat here:http://stackoverflow.com/questions/35089959/bluetooth-low-energy-avaible-devices-listview — Javierd98, Feb 12 '16 at 16:12

score 0 · Answer 1 · answered Apr 07 '16 at 14:05

Assuming you're asking for API>21 (the earlier adapter apis startLeScan(), stopLeScan() are deprecated, please try the following:

if (bluetoothAdapter != null) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        leScanner = bluetoothAdapter.getBluetoothLeScanner();
    }
}

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        scanCallback = new ScanCallback() {

        @Override
        public void onScanFailed(int errorCode) {
            super.onScanFailed(errorCode);
            Log.d(TAG, "onScanFailed: errorCode: " + errorCode);
        }

    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        super.onScanResult(callbackType, result);

        Log.d(TAG, "onScanResult: Scan Result Callback Type = " + getCallbackType(callbackType));
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Log.d(TAG, "onScanResult: Device = " + result.getDevice().getName() ;  --> Here, instead of the log message, you could add to an array and put them into a list on UI thread.

        }
    }

    @Override
    public void onBatchScanResults(final List<ScanResult> results) {
        super.onBatchScanResults(results);

        Log.d(TAG, "onBatchScanResults: ");

    }

If you're using API <21, you would use startLeScan() and get the scan results under onLeScan(). Pls. refer to http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html on the APIs.

Android Bluetooth Low Energy devices listview

1 Answers1