I have a question about Core bluetooth in swift language,
Is this framework can determine the distance by meter between two devices ?
And it have working on background?
Thank you
Not normally, but features like this are being added as part of the new contact tracing API
https://www.apple.com/covid19/contacttracing
Before that, device to device Bluetooth could not be in the background.
Note: you will not be able to use this API unless you have a legitimate health app backed by a government or established health organization.
Related
I am trying to prototype a solution to a problem and am currently exploring multiple routes I could try. Is it possible for one iOS device, running a certain app, to communicate directly with another iOS device, running the same application - without the need to be on the same LAN?
Solutions I am currently investigating are using Bluetooth and ad-hoc wireless connections.
Ideally, the application when installed would ask the user for the required permissions, and then would accept and/or send data to/from another client after a handshake had happened.
My concern with Bluetooth is that 'pairing' would need to happen with every device, rather than happen in the background once the user has installed the app. I have a feeling what I am talking about isn't possible from what I've been reading elsewhere on Stackoverflow.
Take a look at Bluetooth Low Energy.
https://developer.apple.com/library/ios/#samplecode/BTLE_Transfer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012927
Here is another example,
https://github.com/KhaosT/CBPeripheralManager-Demo
You might also want to look into GameKit and peer-to-peer connectivity there.
I can't tell you anything about it, but you might try looking at iOS 7. If that's an option, I'd take a look. Can't talk about what it is because of NDA though.
Depending on what you need to communicate, you could try checking out this project, which lets you share arrays of strings between iOS devices over Bluetooth LE.
You don't need to "pair" the devices and it can still communicate while the app is in the background. SimpleShare
Hope it helps!
From the documentation of MultipeerGroupChat:
MultipeerGroupChat sample application utilizes the Multipeer Connectivity framework to enable nearby users to discover, connected, and send data between each other. This sample simulates a simple chat interface where up to 8 devices can connect with each other and send text messages or images to each other. Here you will learn how to bring up framework UI for discovery and connections and also how to monitor session state, listen for incoming data and resources, and send data and resources.
This is an excellent example at developer.apple.com here is the link
https://developer.apple.com/library/ios/samplecode/MultipeerGroupChat/Introduction/Intro.html
Also this tutorial from Ralf Ebert demonstrates how to use Multipeer Connectivity framework for peer communication should help you.
https://www.ralfebert.de/tutorials/ios-swift-multipeer-connectivity/
I am looking to write application for iPhone which will be able to control radio and CD player in car. Radio and player have Bluetooth connection available.
I started this question in order to obtain all informations I need for this one one place. I have few questions, but if you find anything I didn't ask important for me to start developing this application, please, let me know.
I have read about AVRCP profile and Bluetooth device in car supports AVRCP 1.3, which is good enough for me, having in mind controls which can be performed in that protocol version.
I read a lot about people saying "Apple device can only interact with each other", "Apple device can't be connected via Bluetooth to non-Apple device", "MFi program is obligatory if you want to do that", "MFi is not needed", etc. My first question is:
1)Is it even possible to pair iPhone (4, 4S) with radio and CD player in car via Bluetooth and control radio stations and music with any iPhone version? If yes, what are the limitations for making this kind of successful Bluetooth connection?
There is also very few informations about roles in which iPhone can work. For AVRCP there are two kind of roles: controller and target role. By reading this paper: https://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf I didn't find answer to my second question:
2) Can iPhone act as a controller and issue all available commands stated in AVRCP 1.3 to target device (radio and CD player)?
I would also like to know about available frameworks for this particular problem. I know there are several of them, but if anyone recognizes the right one for my problem, I'd like to know:
3) Which framework for interacting with target device should I use?
From developer point of view, I am also interested in available APIs for interacting with connected Bluetooth device. Since I am making my own application and assigning actions to buttons, inside of methods assigned to buttons I need to perform message sending to target device. So my next question is:
4) Does anyone know how if there's a way to send commands to target device (start/stop/pause/forward/backward, etc) as part of some API provided in XCode, or each message which I attend to send via Bluetooth to target device I need to make according to protocol documentation (make entire message (header, body, command part, etc) by myself)?
AVRCP was my thought for accomplishing this application. If I am wrong, please let me know.
Bluetooth has different profiles and when message is sent from one device, as far as I understand, profile itself handles message and interprets it and delivers to target device so target device can understand it. I do not understand how a message sent from iPhone to target Bluetooth device is handled from the moment I send it from my Objective-C (or C) code. That's the main doubt I have and it is related with question 4 - do I need to make raw messages in correct format in order to send AVRCP commands to device or I can use some API which will recognize those messages as AVRCP (or any other kind) and deliver it to target device?
This last question (if I suppose there is any kind of positive answer to all previous) concerns me the most from developer point of view. So, if anyone had maybe experience with this specific problem, I would appreciate any kind of answer or advice.
I am really looking forward to your answers. I hope that constructive and useful discussion will start on this topic and that lots of useful informations will be written.
Best regards.
You can do it using CoreBluetooth if your device (CD Player) is Bluetooth 4.0 LE compliant
Most likely you shall not be able to do it even if your car CD player has BLE 4.0.
With Core Bluetooth devices act as "Central" (client) or "Peripheral" (server), the peripheral "has data" and expose services with characteristics (variables). The central (client) reads data from the peripheral or subscribe for notifications.
Your only chance is to connect to the CD player as peripheral (server) and your iPhone being the central (client). In this case the CD player must expose services that allow you to control it. To be honest I do not know how this can be done, since the central (the iPhone) will read data and receive notifications from the peripheral, not vice versa.
Reversing roles, implementing iPhone as peripheral makes sense, but there is no predefined Bluetooth LE service for remote control, so your car CD player does not know what service to expect from you. It might work using HID service (Human Interface Device), used in general for keyboards and mouse, but according to this post the HID is forbidden by Apple on iOS.
I'm trying to determine what functionality I can add to a BT accessory by paying for the MFI authentication coprocessor. For example, could I...
A. Pass location data to the accessory?
B. Push incoming SMS messages to the accessory?
C. Launch my app on the phone from the accessory?
As Dennis mentioned, all information regarding the MFi program is covered under a VERY water tight NDA. However, what can be said is that all devices that connect to the iPad through Bluetooth or the docking connector port are accessed through the External Accessory framework. Documentation on the External Accessory framework is easily accessibly from Apple's documentation pages and can also be easily googled.
Communication with devices through the External Accessory framework is fairly simple once you've established a connection with a device. In short, the process is to find the desired connected accessory from an array of devices, establish a connection session and the session object contains a input and output stream. Data by creating a delegate that with the device and finally, monitor the associated input and output streams which you use to communicate with the device.
Again, the majority of the information associated with MFi is tightly sealed. However, as far as connecting to devices (that you have the right to connect to) is simple, well documented and is easily searchable since the framework is part of the standard, iOS library.
One other note on Bluetooth. There is also a Core Bluetooth framework that is available with iOS 5.0 and up. This is a much simpler framework that you can use to discover and auto pair with Bluetooth Low-Energy devices (which are part of the new Bluetooth 4.0 spec.)
If you are planning on making an iPad application or desire to have a fairly high level of backwards compatibility with earlier iOS devices, I wouldn't recommend using the new CoreBluetooth framework. The reason is because only the iPhone 4S and the soon to be released "New iPad" have the necessary Bluetooth chipset to connect with Bluetooth LE devices.
All Mfi information is under NDA.
It dosent cost anything to sign up and get access to the information , you can do it here.
https://developer.apple.com/programs/mfi/
Is it possible to identify devices around me that have their bluetouth enabled?
I don't need to communicate with them, just know they are there.
I am looking for something similar to android's BluetouthDevice.startDiscovery()
Is something like this possible?
Apple turns out to be very restrictive about Bluetooth communications for iOS platform.
Focusing about a native application with Xcode (but not PhoneGap based - PhoneGap is a Xcode plugin that allows web apps to be converted into native ones; btw it gives a quite nice but limited access to underlying hardware resources) for a iOS device to communicate with bluetooth devices (even with discovery actions) the following conditions have to be met:
-) The device you're trying to discover must be equipped with Apple Bluetooth authentication chip (you can ask to Apple directly for the MFi program);
-) Internally your app must declare a protocol name (e.g.: net.yourcompany.proto0) which the devices you connect with must conform to;
-) You must use Apple's External Accessory Framework to establish communication with such devices.
In short, by this procedure Apple guarantees that the only Bluetooth communications an iOS device can establish are just with authorized and certified Bluetooth devices.
I've gone 400 Mph about this thing but I hope it can give you some pointer to start your search.
The topic is too wide to be treated here in its full length.
One thing you might want to look into is Bonjour and NSNetServiceBrowser.
You can publish a service and also search for other services around you. There are ways to run Bonjour in the background (http://stackoverflow.com/questions/6345554/bonjour-in-the-background).
The only limitation with this approach is that everyone else would also need to be running the app as well. Also, by default Bonjour discovers over both WiFi and Bluetooth, something else you would probably need to look into.
Does anyone know what kind of range can you get from the iPhone
bluetooth? Also, would the connection be strictly one to one? I know you
can choose from a number of peers to connect to but once the connection
is established, it seems you can only transfer data between one peer? So
basically, is it possible to create some kind of "multiplayer" experience?
Just answering the range part of your question...
The 10 meter figure for class 2 devices (of which the iPhone is an example) is very much a guideline.
The range of a Bluetooth device is limited by many real world factors. The 2.4 GHz radio frequency used by Bluetooth is strongly absorbed by water. For example, consider an iPhone connected to a Bluetooth mono headset. If the headset is in one ear and the iPhone is in your trouser pocket on the opposite side of your body, then there's a lot of water between the two devices. This will often cause a significant amount of packet loss in practice (you can hear this in the audio being carried). So, in this case, the range is about one meter.
At the opposite extreme, two class 2 devices separated by nothing more than clear air can get ranges of hundreds of meters.
Other factors that influence things are:
Interference - Lots of things use 2.4 GHz. WiFi, for example can cause problems.
Antenna design - Space and cost constraints often mean that the antenna design is sub-optimal. I don't know how good the iPhone is in this respect.
Walls - Generally walls attenuate Bluetooth signals. However, sometimes they are useful reflectors.
Quality of hardware - Some chips work better than others. Even different firmware revisions of the same chip may perform differently. Different versions of the iPhone probably have (or will have) different chips in them.
Protocol - It is possible to work around poor signal quality with error correction and retransmission. Even if the iPhone SDK forces you to use a particular protocol, careful design of your application can make a difference.
So, in summary, you should probably do some real world tests.
The connection is one-to-one, but you can create an adhoc network with one of the phones acting as the master/coordinator. The other phones would route all their communication through the master/coordinator.
One device can theoretically connect to 7 devices. according to the master-slave role, the device can multiplex between each of them giving the user an impression that you are connected to all of them simultaneously. Bluetooth specification does not stop you from doing that.This is theory.
Now for the iphone, whether it can connect to to more than one device can only be answered by apple or someone who knows the iphone bluetooth API. But I am pretty sure the bluetooth chip inside iphone should be able to connect to more than one device.
Range is essentially going to be good enough for a normal sized room to be covered. It can be longer or shorter depending on environmental circumstances, but remember that bluetooth was created to implement short range connections.
A bluetooth device can be part of a piconet of eight devices, one master and up to seven slaves. The slaves cannot communicate with each other, they must talk through the master, think of a star topology with the master in the center. The iPhone SDK has a GameKit framework that can be used to create the network for multiplayer games. Go to developer.apple.com at look at the GKTank and GKRocket sample code to see how it's used. These games only support two players, but the GameKit framework supports more. Look at the app store and you will see games that have four or more players.
Hope this helps to get started.
Apple iPhone 3G has a Class 2 bluetooth module. Class 2 Bluetooth devices have a communication range of 10 meters.
At a given instance a device can connect to just one device because it follows a master/slave communication model. But still we can perform a multiplexing. So we can virtually connect to more than 1 device and by rapidly changing the connected device.
I found a good article here. It explains bluetooth very well.
According to the my knowledge, multicasting is not impossible with bluetooth. So gaining a multiplayer experience is NOT impossible.
The bluetooth in the iPhone is Class-2, with a 10-meter range, approximately.
Unfortunately I can't answer the other parts of your question.
One device can be connected up to 8 others. It all depends on the iPhone bluetooth API (which I don't know anything about), but with Bluetooth itself you could then send data to multiple devices.
I tether my iPhone to my laptop over bluetooth every day, and I seem to remember having done that at the same time as using a bluetooth headset. YMMV.
It’s the latest incarnation of Bluetooth, the wireless device-to-device technology that allows your phone to talk to headsets, car stereos, keyboards and other devices directly, without the need for a router or shared wireless network.