Finding bluetooth device with phone

Find Bluetooth devices

Using the BluetoothAdapter , you can find remote Bluetooth devices either through device discovery or by querying the list of paired devices.

Make sure you have the appropriate Bluetooth permissions and set up your app for Bluetooth before attempting to find Bluetooth devices.

Device discovery is a scanning procedure that searches the local area for Bluetooth-enabled devices and requests some information about each one. This process is sometimes referred to as discovering, inquiring, or scanning. A nearby Bluetooth device responds to a discovery request only if it is currently accepting information requests by being discoverable. If a device is discoverable, it responds to the discovery request by sharing some information, such as the device’s name, its class, and its unique MAC address. Using this information, the device that is performing the discovery process can then choose to initiate a connection to the discovered device.

Because discoverable devices might reveal information about the user’s location, the device discovery process requires location access. If your app is being used on a device that runs Android 8.0 (API level 26) or higher, consider using the Companion Device Manager API instead. This API performs device discovery on your app’s behalf, so your app doesn’t need to request location permissions.

Once a connection is made with a remote device for the first time, a pairing request is automatically presented to the user. When a device is paired, the basic information about that device—such as the device’s name, class, and MAC address—is saved and can be read using the Bluetooth APIs. Using the known MAC address for a remote device, a connection can be initiated with it at any time without performing discovery, assuming the device is still within range.

Note that there is a difference between being paired and being connected:

• To be paired means that two devices are aware of each other’s existence, have a shared link-key that can be used for authentication, and are capable of establishing an encrypted connection with each other.
• To be connected means that the devices currently share an RFCOMM channel and are able to transmit data with each other. The current Bluetooth APIs require devices to be paired before an RFCOMM connection can be established. Pairing is automatically performed when you initiate an encrypted connection with the Bluetooth APIs.

The following sections describe how to find devices that have been paired and how to discover new devices using device discovery.

Note: Android-powered devices are not discoverable by default. A user can make the device discoverable for a limited time through the system settings, or an app can request that the user enable discoverability without leaving the app. For more information, see the enable discoverability section on this page.

Query paired devices

Before performing device discovery, it’s worth querying the set of paired devices to see if the desired device is already known. To do so, call getBondedDevices() . This returns a set of BluetoothDevice objects representing paired devices. For example, you can query all paired devices and get the name and MAC address of each device, as the following code snippet demonstrates:

Kotlin

val pairedDevices: Set? = bluetoothAdapter?.bondedDevices pairedDevices?.forEach < device ->val deviceName = device.name val deviceHardwareAddress = device.address // MAC address >

Java

Set pairedDevices = bluetoothAdapter.getBondedDevices(); if (pairedDevices.size() > 0) < // There are paired devices. Get the name and address of each paired device. for (BluetoothDevice device : pairedDevices) < String deviceName = device.getName(); String deviceHardwareAddress = device.getAddress(); // MAC address >>

To initiate a connection with a Bluetooth device, all that’s needed from the associated BluetoothDevice object is the MAC address, which you retrieve by calling getAddress() . You can learn more about creating a connection in Connect Bluetooth devices.

Discover devices

To start discovering devices, call startDiscovery() . The process is asynchronous and returns a boolean value indicating whether discovery has successfully started. The discovery process usually involves an inquiry scan of about 12 seconds, followed by a page scan of each device found to retrieve its Bluetooth name.

To receive information about each device discovered, your app must register a BroadcastReceiver for the ACTION_FOUND intent. The system broadcasts this intent for each device. The intent contains the extra fields EXTRA_DEVICE and EXTRA_CLASS , which in turn contain a BluetoothDevice and a BluetoothClass , respectively. The following code snippet shows how you can register to handle the broadcast when devices are discovered:

Kotlin

override fun onCreate(savedInstanceState: Bundle?) < . // Register for broadcasts when a device is discovered. val filter = IntentFilter(BluetoothDevice.ACTION_FOUND) registerReceiver(receiver, filter) >// Create a BroadcastReceiver for ACTION_FOUND. private val receiver = object : BroadcastReceiver() < override fun onReceive(context: Context, intent: Intent) < val action: String = intent.action when(action) < BluetoothDevice.ACTION_FOUND -> < // Discovery has found a device. Get the BluetoothDevice // object and its info from the Intent. val device: BluetoothDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE) val deviceName = device.name val deviceHardwareAddress = device.address // MAC address >> > > override fun onDestroy() < super.onDestroy() . // Don't forget to unregister the ACTION_FOUND receiver. unregisterReceiver(receiver) >

Java

@Override protected void onCreate(Bundle savedInstanceState) < . // Register for broadcasts when a device is discovered. IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); registerReceiver(receiver, filter); >// Create a BroadcastReceiver for ACTION_FOUND. private final BroadcastReceiver receiver = new BroadcastReceiver() < public void onReceive(Context context, Intent intent) < String action = intent.getAction(); if (BluetoothDevice.ACTION_FOUND.equals(action)) < // Discovery has found a device. Get the BluetoothDevice // object and its info from the Intent. BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); String deviceName = device.getName(); String deviceHardwareAddress = device.getAddress(); // MAC address >> >; @Override protected void onDestroy() < super.onDestroy(); . // Don't forget to unregister the ACTION_FOUND receiver. unregisterReceiver(receiver); >

To initiate a connection with a Bluetooth device, you call getAddress() on the BluetoothDevice to retrieve the associated MAC address.

Caution: Performing device discovery consumes a lot of the Bluetooth adapter’s resources. After you have found a device to connect to, be certain that you stop discovery with cancelDiscovery() before attempting a connection. Also, you shouldn’t perform discovery while connected to a device because the discovery process significantly reduces the bandwidth available for any existing connections.

Enable discoverability

To make the local device discoverable to other devices, call startActivityForResult(Intent, int) with the ACTION_REQUEST_DISCOVERABLE intent. This issues a request to enable the system’s discoverable mode without having to navigate to the Settings app, which would stop your own app. By default, the device becomes discoverable for two minutes. You can define a different duration, up to one hour, by adding the EXTRA_DISCOVERABLE_DURATION extra.

Caution: If you set the EXTRA_DISCOVERABLE_DURATION extra’s value to 0, the device is always discoverable. This configuration is insecure and therefore highly discouraged.

The following code snippet sets the device to be discoverable for five minutes:

Kotlin

val requestCode = 1; val discoverableIntent: Intent = Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE).apply < putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300) >startActivityForResult(discoverableIntent, requestCode)

Java

int requestCode = 1; Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); startActivityForResult(discoverableIntent, requestCode);

Figure 2: The enabling discoverability dialog.

A dialog is displayed, requesting the user’s permission to make the device discoverable, as shown in figure 2. If the user responds «Allow,» then the device becomes discoverable for the specified amount of time. Your activity then receives a call to the onActivityResult() callback, with the result code equal to the duration that the device is discoverable. If the user responded «Deny», or if an error occurred, the result code is RESULT_CANCELED .

Note: If Bluetooth has not been enabled on the device, then making the device discoverable automatically enables Bluetooth.

The device silently remains in discoverable mode for the allotted time. To be notified when the discoverable mode has changed, register a BroadcastReceiver for the ACTION_SCAN_MODE_CHANGED intent. This intent contains the extra fields EXTRA_SCAN_MODE and EXTRA_PREVIOUS_SCAN_MODE , which provide the new and old scan mode, respectively. Possible values for each extra are as follows:

SCAN_MODE_CONNECTABLE_DISCOVERABLE The device is in discoverable mode. SCAN_MODE_CONNECTABLE The device isn’t in discoverable mode but can still receive connections. SCAN_MODE_NONE The device isn’t in discoverable mode and cannot receive connections.

If you are initiating the connection to a remote device, you don’t need to enable device discoverability. Enabling discoverability is only necessary when you want your app to host a server socket that accepts incoming connections, as remote devices must be able to discover other devices before initiating connections to those other devices.

Content and code samples on this page are subject to the licenses described in the Content License. Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.

Last updated 2021-10-27 UTC.

Источник

Find My Bluetooth Device

«Найти мои устройства Bluetooth», «Найти мои гарнитуры», «Умные часы» и «Найти потерянные устройства».

Последняя версия

App APKs

Find My Bluetooth Device APP

Приложение Find My Bluetooth разработано, чтобы облегчить и помочь нашим пользователям в их повседневной жизни.
В настоящее время мы используем множество устройств Bluetooth, чтобы сделать наши задачи и жизнь комфортными. Со временем эти устройства становятся очень полезными и становятся частью нашей жизни. В офисах, дома, спортзале, ресторанах и т. Д. Мы используем наушники, часы и другие аксессуары для подключения через наши телефоны через Bluetooth.
Нам очень легко пользоваться устройствами Bluetooth, и мы носим их с собой в повседневной жизни. Иногда мы теряем или теряем устройства Bluetooth в незнакомых местах, поэтому приложение «Найти устройства Bluetooth» поможет вам найти эти устройства Bluetooth.
Устройства Bluetooth легко подключаются к приложению Find My Bluetooth, а с помощью поиска и навигации вы можете легко подключиться к своему устройству Bluetooth.
Устройство Find My Bluetooth предоставляет простой измеритель расстояния, который показывает расстояние между моим телефоном и моим устройством Bluetooth после подключения. Расстояние становится все короче и короче, когда вы подносите телефон к подключенным устройствам Bluetooth и, наконец, он легко находит устройство Bluetooth.

Как использовать «Найти мое устройство Bluetooth»:

Нажмите кнопку «Поиск на устройствах» .
Проверьте найденные устройства
Выберите устройство, которое хотите узнать
Посмотрите, насколько вы близки к потерянным устройствам Bluetooth

Источник

How to Find a Lost Bluetooth Device

Andy O’Donnell, MA, is a former freelance contributor to Lifewire and a senior security engineer who is active in internet and network security.

Lisa Mildon is a Lifewire writer and an IT professional with 30 years of experience. Her writing has appeared in Geekisphere and other publications.

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What to Know

• Make sure Bluetooth is on. Download and then open a Bluetooth scanner app and start scanning.
• When found, move around to measure the proximity of the device.
• If you lost Bluetooth headphones or another audio device, send some loud music to it using a music app.

When you set up a Bluetooth device on a PC or mobile device, you usually pair it to another device. For example, you can pair a Bluetooth device with a car audio system or wireless speaker. This pairing mechanism is critical to helping you find a lost Bluetooth device. Learn how to find a lost Bluetooth device using phones and tablets with iOS or Android.

Locating a Lost Bluetooth Device

As long as your headphones, earbuds, or another Bluetooth-enabled device has some battery life and was turned on when you lost it, the odds are good that you can find it using a smartphone and a Bluetooth scanning app. Several of these apps are available for both iOS and Android-based phones and tablets.

1. Make sure Bluetooth is active on the phone. Your phone can’t pick up the signal from the lost Bluetooth device if the phone’s Bluetooth radio is off. On Android, access Quick Settings. If the Bluetooth icon is gray, tap it to turn it on. (You may have to swipe left to find Bluetooth.) It’s also easy to turn on Bluetooth on an iPhone in the Settings app.

When the item shows up on the list, try to locate it. If the signal strength drops (for example, goes from -200 dBm to -10 dBm), you’ve moved away from the device. If the signal strength improves (for example, goes from -10 dBm to -1 dBm), you’re getting warmer. Keep playing this game of Hot or Cold until you find the phone.

On most Android devices, to change the Bluetooth name, go to Settings > Connected Devices > Connection preferences > Bluetooth > Device name. To rename on iOS devices, go to Settings > Bluetooth > Choose connected Bluetooth accessory > Name.

First, make sure Bluetooth is turned on. Next, go to Settings > Connections > Bluetooth. Select the cogwheel next to the device you want to unpair > Unpair.

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