i want to develop an application that is capable of using 2G 3G or 4G depending upon the availability of the network. Because this app will be used in different countries and there is a support of only 2G in some countries while some support 3G or 4G.. i am a little bit confused whether my app will automatically use the Fastest network available or i will have to explicitly code for each one.
According to Apple's documentation, WiFi is what is chosen first. If that fails, then it goes to the next available (and presumably fastest) cellular network data connection.
This is the kind of thing programmers do not have to worry about when designing apps for iOS.
iOS will take care of whether wifi or 3G is used. You don't need to worry about that.
If you have operations in your app that use a lot of data you may want to restrict them to when the user is on WiFi (or at least warn them). The reachability example shows how to do this, among other things. Worth looking into as apple have been known to reject apps that use excessive amounts of cellular data.
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I am new to iPhone/iPad development and I am close to finishing up my first app and I am looking for some general advice.
I know it is important to test on actual devices and not just the simulator. What are the types of things people generally encounter when testing on a deal device that they don't see in the simulator?
The app itself is mainly a way to track online deals and that type of thing. It doesn't need anything special in term of using things like the camera or GPS.
It's just general usage testing. The device performs in an entirely different environment than your computer, and it's the best way to make sure if you push your app out to devices, that nothing unexpected will happen. For example, the phone/pad may have limited data coverage, low memory situations, incoming calls etc.. These situations are a lot more common on devices, then when people emulate it though the simulator.
On a hardware point of view, the device uses a different processor architecture than your Mac, which also needs to be accounted for (not as much as other cases, but you need to cover your bases). The Mac also cannot reliably emulate RAM, Disc Space, Processor Speed etc...hence testing on the device is useful here also.
Obviously there are some features you can only test on devices, such as Camera, GPS (and not so obviously iPod library usage), and if your app uses them it'd be careless not to test on a device.
Overall if you're intending to release your application to the App Store, or to devices at least, it's worth testing on the device itself. Only then can you be sure that it will act and perform as expected on the platform you intend to target. The simulator is only a simulator after all, not the real thing!
First of all: the user experience is very different.
The mouse based interaction is very different from a touch interaction. focusing at a monitor feels very different then looking on a device on the palm of your hand.
Also the experience of animations running on the simulator and the real device can be very different.
And the usage in the simulator won't tell you anything about the battery consumptions to be witnessed on the real device.
My opinion: every app that will be shipped to the App Store or customer for testing should be tested several different real devices. No excuses.
Simulator runs a lot slower than the real device.
Real device could run out of memory when Simulator doesn't or vice versa.
In app purchases, if you have included them
Orientations (not that
they are unavailable on simulator, but it is easy to forget it
there!)
App life cycle testing - bringing your app to foreground and
background.
Network access - can matter when you access the network from device through wireless or cellular network vs LAN/wifi on your mac. There is a huge testing to be done under the umbrella called Reachability if your app uses any of the resources across the net. You are bound to provide an alert if network is unreachable before using any such resources, as per app store requirements.
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.
I'm in the process of planning out a personal project that will be a media player and one of the things I would like to do is be able to dock my iPod touch (or any iPod or iPhone) and control it and play music off it like the speaker docs do that you can buy.
I found some information while searching around online for this but my question is can I make up a cable and use the serial protocol from any device or does Apple have this locked down so only certified/approved devices can communicate this way?
If you are looking to do this for yourself, I would recommend jailbreaking and the following resources on the web. These describe some methods of the Apple Accessory Protocol, and include some parts (at sparkfun) to execute. To get approved for the Apple method you need a corporation (or similar structure) and even legal counsel before you can get approved to even see the agreement you have to agree to in order to join.
http://nuxx.net/wiki/Apple_Accessory_Protocol
http://www.sparkfun.com/categories/101
There are even some great articles out there such as:
http://courses.cit.cornell.edu/ee476/FinalProjects/s2007/awr8_asl45/awr8_asl45/index.html
Good luck!
EDIT:
Since this is a relatively popular post, keep in mind that you can now use Bluetooth 4.0 LE for serial communication without approval from Apple (other than AppStore approval).
https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/AboutCoreBluetooth/Introduction.html
Only devices in the Made for iPod program which use Apple's proprietary authentication chip can communicate with the External Accessory framework on the iPhone or iPod touch. Such devices must also expose a protocol that iPhone applications can use.
It is a reasonably involved process to be approved as a Made for iPod vendor of products (similar to the App Store approval process, but for hardware), but it has become a lot easier than it used to be. With iPhone OS 3.0, Apple has opened up the program to many more third parties than just the usual large accessory providers.
In your case, I'd actually wait and use another vendor's iPhone-controllable stereo. Manufacturers are just starting to come out with hardware controllable via iPhone applications, so it's only a matter of time before one of the larger accessory providers creates something like what you want. If they expose a protocol for controlling the device, all you'll have to do is write your application to control the device via that protocol.
I'm in the process of getting hardware for an iPhone prototype, and I'm wondering if it's possible to access bluetooth (ExternalAccessory, Bonjour or GameKit) exposed by development box (eg. a macbook) using the SDK's simulator as of the latest version (3.1.3 at the time of writing)
Before I get any answers on the subject, I accept that I will need an iPhone for the actual development - this is simply a prototype.
I'm not sure I understand your question entirely.
I can state that in iOS (as of May 2011) the only access you have to bonjour is through the Gamekit functionality. That functionality is fairly robust, but (for instance) you will not be able to create a BT based bonjour service that other non-iOS BT enabled devices can find.
On the simulator, even if the underlying device HAS bluetooth capabilities, you will NOT be able to perform "real" bluetooth operations. Instead the simulator will simulate some capabilities, and ignore others. You really do need multiple devices to load your code onto and run, in order to test out BT code.
Bluetooth connectivity is inaccessible using the Simulator. If WiFi is good enough for you, that works with Bonjour and GameKit on the Simulator as well. Otherwise, just like for the accelerometer and several other components of the device, you will need an actual device.
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.