I'm developing an andoird application that needs to know how many and what kind of other android devices are using the same application. After digging about BLE and Wifi Direct, I'm doubt that there is no efficient way to do so, since BLE API in android can't advertise a device and Wifi Direct will prevent the device from connecting to Wifi routers.
My requirements are it should be done power efficiently and cause minimal impact on normal network usage for users.
You could be using the Nsd (Network Service Discovery) APIs provided by the Android SDK.
This will use under the hood multicast DNS to perform the discovery of remote services on the local area network. You will have to build an advertisement application to be installed on a remote device, and have your client app discover the remote device.
You might want to take a look at the NsdManager class documentation which provides useful pieces of informations about how the API is working.
Related
I'm developing an app to communicate with a BLE device (Sensor puck from Silicon labs) and get whatever it is broadcasting.
I have NO experience in developing any sort of Bluetooth application using Android.
Do I need to manually pair it to the BLE device? I downloaded Sensor puck app from Play store, it automatically started to read from the device. I don't understand how since I didn't pair it.
Do I need specific API to communicate with the device? Is it like, I connect to the device and unpack the data which the device is broadcasting?
Any other information related to BLE application development would help.
Thank you.
PS: I can't use the app from the play store as I need the data from the device for some other processing.
I have a little experience with developing BLE apps.
Do I need to manually pair it to the BLE device?
I haven't encountered use case where I needed to pair mobile device with BLE device. Basically, you can communicate with BLE devices without pairing with them. BLE devices constantly emit signals and you can read these signals. Usually, from the emitted signals, you can read name of the device (or producer name), MAC address, RSSI signal from which you can compute distance from your mobile device to BLE device. Some BLE devices emit other information like temperature read from their sensors, etc. You can read information from more than one BLE device during the single scan.
Do I need specific API to communicate with the device?
Google provides API, which you can use to communicate with BLE devices. You can read more about it at: http://developer.android.com/guide/topics/connectivity/bluetooth-le.html. You can also use some third-party libraries allowing to communicate with BLE devices. Most of them are dedicated to so called Beacons, which are simple, tiny BLE devices.
Exemplary APIs for BLE Beacons:
Estimote
Kontakt.io
AltBeacon
ReactiveBeacons - this is open-source project, which I'm currently developing, so if you have any questions regarding it, you can ask me directly
Other projects:
Android Bluetooth Demo - this is very good and simple project, which can help you to understand how to use BLE API provided in Android SDK
Other information:
To communicate with BLE devices, of course, you need to have Bluetooth enabled on your device, but regardless of this permission, you also need to have Location enabled on your device and added location permission to your app. I guess it's done due to the fact, that you can use BLE devices for creating micro-location services.
I gathered some references concerning BLE for myself. You can check them here: https://github.com/pwittchen/ReactiveBeacons#references and maybe they will be useful for you as well.
Regards,
Piotr
it might be too late, but it also might be helpful for other users. So Sensor Puck works like a simple beacon and it doesn't require any pairing. You just have to scan all bluetooth devices nerby and verify received ScanRecord object. You don't have to use any specific libs or API, Anroid sdk contain all necessary api for such case (please see BluetoothAdapter startScan, startLeScan, etc). Also you can find an example how to parse raw data in my demo project https://github.com/alexeyosminin/sensor_puck_demo
I'm implementing the wifi p2P (direct wifi) in my android application, in order to share small files between clients.
I'm following these pretty good tutorials:
http://developer.android.com/guide/topics/connectivity/wifip2p.html
http://developer.android.com/training/connect-devices-wirelessly/wifi-direct.html
I can now discover peers and connect to them.
I'd like to know if there is a way to filter the discovered peers. The first thing I'd like is to show only the peers who are using the same application. Indeed, currently my application show me all peers (phones, tablets, printers with direct wifi). I think it would be easier for the user to only have the compatible peers (peers also using the application).
If this work, I'd like to improve this and only show peers who ave accepted to share their files (a client can receive files or/and share their own files if he had activated it)
So, is it possible to do these types of peer filtering?
Thank you.
There is a way to achieve this ...
Adding Network Service Discovery (NSD) to your app allows your users to identify other devices on the local network that support the services your app requests. This is useful for a variety of peer-to-peer applications such as file sharing or multi-player gaming.
first you need to do
1.Register Your Service on the Network
2.Discover Services on the Network
3.Connect to Services on the Network
4.Unregister Your Service on Application Close
Take a look here.
So using NSD your app will only see devices that supports the services your app requests, cool isn't it..?
I will get back to you if I come up with some intelligent logic for the second part.
My computer does not have any Bluetooth capability, however it has WI-Fi capability. My phone has both.
I was asking myself if there is anyway to "stream" Bluetooth over WI-Fi?
Thanks!
The short answer is no. Easiest would be to purchase a bluetooth dongle for your computer.
Yes, tunneling one type of communication through another is generally possible (within the limits of the Android Bluetooth API), but as it is an obscure need you will probably have to write the bridging server to run on the Android device yourself - this is after all a site for questions about software development. Additionally, it will work best when the app hosting the server is in the foreground, as Android makes no guarantees about keeping services running in the background.
On the PC side, this bridged Bluetooth capability will probably not trivially present as an ordinary Bluetooth adapter, so you would be limited to using custom applications which known how to talk through your bridge. The exception would be if you also spend time figuring out how to write a device driver for your host operating system which presents it with traditional Bluetooth APIs, at least to the greatest degree possible.
I have an android app, it does the following:
Connects with a server to read and update a database at the same time as others.
I want to convert this to an app that does not need an internet connection. Therefore i would like to know if its possible to have an android device acting as the server with the database, whilst multiple phones connect to it via bluetooth getting and updating the information in the database?
Thanks
Yes. It possible.
However all of your devices will have to be located nearby, so they can connect to each other through bluetooth.
You can take a look at Android Bluetooth API.
However, my recommendation would be to use Wifi instead of Bluetooth. YOu will need additional WiFi router. However, you won't need to deal with Bluetooth API in such case.
You will only need to write a server on one of Android device and the rest of devices will work the same (as now)
There are a few options to doing so, that don't involve a server. Both of them require a slightly different approach than both devices connecting to a server.
Wi-fi Direct- Only available with Android 4.0+.
Bluetooth
Personally, I have been using the Bluetooth option, and not found it terribly difficult. Essentially, you have to do the following to make it work.
Have one of the devices listen for a connection. If it is unpaired, you will have to make the device discoverable.
The second device needs to initiate a connection. It can do this by looking at the known devices and trying to connect to one, or listening for a new device
After the two devices connect, they must initiate some kind of a communication protocol. The communication is essential a serial connection.
Blue-tooth requires that the devices be within about 10 m of each other. Wi-fi direct will allow somewhat further, but as mentioned, is less supported. It is possible to allow for both communication methods, but is somewhat challenging.
What is the best way for an Android app installed on two devices to communicate with each other? Can the devices connect directly without using text messaging?
You have several options, depending on your requirements and setup:
If your devices are very close to one another (up to about 10 meters), you can communicate using Bluetooth, as Derek suggested.
If your devices are somewhat further away, but within WiFi range of each other (up to about 100 meters), then they can communicate with each other using the Peer-to-Peer WiFi API, documented here (part of the Android Wireless API). This does not require a WiFi router to be present, and the devices will find each other and communicate directly. This does however require Android 4.1 or higher.
The Android Wireless API will also work if your devices are on the same local network (i.e., use the same WiFi router), even if they are not themselves within range of each other.
If none of these options are viable/guaranteed, then I agree with Derek that the easiest way would be to use ServerSocket and Socket to create a server/client interface through the Internet. Here is a sample application doing that. The main problem you might encounter is that if the server is sitting behind a NAT (such as a home internet router), you will have to configure the NAT to forward the incoming packets to your Android server.
You can connect them via bluetooth using BluetoothSockets. Android developer website has pretty good documentation on this.
http://developer.android.com/guide/topics/wireless/bluetooth.html
Or if you'd rather (and have internet on both devices), you can use regular Socket's.
http://developer.android.com/reference/java/net/ServerSocket.html for server side
http://developer.android.com/reference/java/net/Socket.html for client side
If you have a large amount of data to transfer, internet sockets have a greater data capacity and will be faster. The other advantage is that there is no such thing as "out of range". You can connect the two devices wherever internet is available, whereas with bluetooth they have to be within bluetooth range of each other
you can use PubNub. it handles all networking and you should only care about messages.
it has great API to work.
(Thanks to #Ian Jennings : Can we send data from an android device to another android device directly (p2p) without server in the middle?)
Depends on what you are doing. If you have a server, you may be able to send some message to it and have it pulled by the other device (assuming both clients have the app installed). I think this would be the most intuitive way (but it really depends on what you are communicating).
Text messaging and email might work, but you (or the user) needs to know the numbers/emails associated with a device to do that.
you should have a look at WifiDirect
Wi-Fi peer-to-peer (P2P) allows Android 4.0 (API level 14) or later
devices with the appropriate hardware to connect directly to each
other via Wi-Fi without an intermediate access point.
As was already suggested, sockets are the easiest way to accomplish this if your devices are all connected to a network.
There are things to accomplish here:
Use Network Service Discovery to find devices running your app
Connect to other instances of your app using a socket
For a complete tutorial you can check this out
ShortAnswer: Yes
Data can be sent directly.
In order of range:
1 Bluetooth
2 wifidirect
3 maybe.. GSM hardware direct?
After that, options again in range order:
4 tether or network
5 Internet
The android NSD API is meant to do the exact same thing you are trying to achieve! The example bundled with SDK is self explanatory!
please check:
Android NSD API example