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.
Related
I know some basic about iOS programming, now i want to connect my app to another non iphone device e.g. connecting to a bluetooth device that can control a light bulb on and off, or control any furnitures.
My question is, besides iOS xcode, what kind of program i need to learn in order to achieve my goal?
Is there any sources that i can learn from it?
For Bluetooth Low Energy devices, you can use the CoreBluetooth framework to access them.
For Classic Bluetooth devices or accessories that make use of the Dock connector, the protocols are not open, and joining the Made for iPhone (MFi) program is required. I do not suggest this for beginning.
My suggestion is to buy for example a Polar Heart Rate Belt that supports Bluetooth Low Energy. These use standard protocols. Sample code is available from Apple that shows how to read out the heart rate from such a device.
As soon as you have mastered the heart rate monitor example, a next step would be to acquire a programmable Bluetooth Low Energy chip (however, often, the development tools for those are rather expensive!). Those chips can be programmed with custom profiles to listen for Bluetooth Low Energy connections and then performing defined operations (lighting a LED) when writes to characteristics occur. So, you are not limited to heart rate monitors and similar devices.
Keywords that you can search for: GATT protocol, Bluetooth Low Energy, CoreBluetooth.
I know that it's a steep learning curve for beginners, but the area is pretty new. However, I can assure you that it's a fun area.
I also think that you should look in to embedded C programming for the slave device (Heart Rate Monitor)
You could get a tod Smart Beacon Development kit for ~$150 and then use BGScript to code the firmware to control the BLE device from your phone or pc. todhq.com for more info.
I would like to develop an app using iOS gamekit library and I am curious to know what the maximum range is between the two devices. How far can they stay connected and communicating?
Thanks!
I think you should go check the bluetooth and wi-fi specs, rather than thinking that the GK decides how far you can play:)
I'm looking to connect my iPhone to an RS-232 serial device via Bluetooth. Has anyone implemented this successfully and can offer advice on hardware to use? It's kind of tricky because of the need for the Apple Authentication Processor with the device. The best potential device I've found is this guy but it only comes in an embedded package, its serial port interface is just logic-level UART rather than line-level RS-232, and I can't find a supplier with it in stock.
Any thoughts would be appreciated.
I'm considering just using WiFi to serial instead, but please ignore that possibility for the purposes of this question.
most of the question was answered by yourself already.
Basically you have 5 (+2) choices.
Join the MFi program. This might be hard to impossible if you are not part of a at least mid-size company.
Buy the OEM Bluetooth Module. I'm not sure if this is even allowed by the apple policies.
Use WiFi. Keep in mind that you want to use a wifi chipset that can act as at least ad-hoc access point. Those chipsets are quite expensive, and you have to think of a way to join existing networks (customers don't want to leave their home network to use your product). This will add a lot of cost to the BOM of your device.
Jailbreak might be an option. I never tried to use accessories with a jailbreak, so I don't know if it's possible to use bluetooth without authentication.
Work with a company that is member of the MFi program.
(Maybe an option, and depending of the speed you want to have via RS232: Eventually you can convert the audio output of the head-phone jack to RS232 levels and vice versa)
(Not really an option: develop for Android and do whatever you want)
If you jailbreak your device, you can use BTstack.org (disclaimer: I'm the author of BTstack) to connect to a Bluetooth device that supports the Serial Port Profile. You can get Bluetooth Modules that implement SPP and provide UART level output. As David R. above points out, you then need a UART to RS232 converter, e.g. the MAX232.
Ok. Another option. There are one or two companies that sell RS232 cables for iOS, eg. Skywire here: http://www.southernstars.com/products/skywire/index.html
Then, you could uses a Bluetooth RS232 extender, which consists of a RS232-to-SPP and a SPP-to-RS232 pair. Ugly, but within Apple's rules.
Well. It seems like my answer could be something you didnt ask for.
But the guy you referred to is the answer. Buy his product and you are good to go, all you need is a MAX232 chip. Converts logic level UART to RS232.
the diffrence high + voltage low zero voltage is converted to high +~10volts low -~10volts.
I use the MAX232 chip with my microprocessor, that uses logic level USART to communicate over RS232.
There is a lot of tutorials out there explaining how to hook things up.
This product works: https://serialio.com/product/bluetooth-serial-adapter/bluesnap-smart-bluetooth-40-ble-rs232-adapter
The only downside is that the adapter requires power.
It should be possibly I would think to create something in the middle that accept the bluetooth commands and convert them to serial, similar to what this does with TCP connections: https://www.npmjs.com/package/stellar-socks
(I am not interested in pure theory, but as a practical near or mid-term possibility, say within 12-24 months.)
As a developer familiar with (but not specializing in) two major smartphone platforms, should I expect an Android library to come out which can spoof itself onto an iPhone app's GameKit-based network. It seems reasonable that a Bluetooth interface between platforms might square the opportunity to make useful applications, in the same way that modems benefited PC/Mac platforms via Metcalfe's Law.
I am looking for one of two answers:
Is this obviously not likely (e.g. because of encryption)? If so, what is the reason? Is it possible in principle, but requiring years of reverse-engineering (like SMB/CIFS/Samba)? Or is it a no-brainer and just a matter of time? Please give evidence supporting your reason.
Is there an alternative way to have direct peer-to-peer networking besides GameKit? For example, a hand-rolled network using Bluetooth or ad-hoc WiFi? It would be nice to spoof an Android device into an existing iPhone app but my main question is, can the devices speak with each other at all!
Yes, it is possible. GameKit is a protocol using TCP and/or UDP over a BNEP Bluetooth connection. It also uses a trick to identify other iOS devices using the Extended Inquiry mechanism in Bluetooth 2.1+.
I was able to simulate the EIR responses, now, someone needs to reverse engineer the GameKit protocol. This doesn't need Bluetooth, as it is also used for GameKit connections over WLAN.
If anybody can re-implment GameKit for WLAN connections, I can finish the Bluetooth version.
No, and it wont come soon or even at all... Apple pride themselves with their security features, and bluetooth connections can access private data. There will probably not be any cross platform bluetooth framework until something is agreed upon by both companies.
Bump as said by a previous answerer uses a remote server, and the data transferred is not via BT.
GameKit is Bonjour so a Bonjour (which is on IP) over Bluetooth on Android should work.
That should be possible as Bluetooth is capable of setting up tcp/ip networks. Though I have no knowledge of the IPhone SDK whatsoever, but Android does have a BluetoothSocket and BluetoothServerSocket for TCP connections.
This article, http://blog.moritzhaarmann.de/blog/2014/04/27/sorry-state-of-p2p/ written in 2014, suggest it is possible via Bluetooth LE. Available in Android 4.3+ and iOS6+
Two issues:
According to the Android Dashboard only around 30 percent of Android devices support Bluetooth LE https://developer.android.com/about/dashboards/index.html?utm_source=ausdroid.net
Communication between Android-to-Android must be done using some other method (which is not a big problem) because Android devices cannot act as server for B LE connections.
Bounjour on the iPhone gives you full access to all of the Bluetooth protocols, so you don't have to use GameKit. As for when someone will provide an easy to use iPhone to Android GameKit like framework - hard to tell.
An iPhone can already talk to any other Bluetooth device using Bonjour today.
-t
It is absolutely possible! In fact I am amazed that more people haven't done it!
Theory:
Bluetooth is just a wireless socket that you push data across and it comes across the other side, just like tcp/ip.
Practice:
http://www.techcrunch.com/2009/11/11/bump-goes-cross-platform-with-new-android-app-upgrades-iphone-version-too/
Better yet, Bump is cross-platform, which means that you can bump an Android phone with an iPhone and it should work seamlessly.
I was wondering what amount of time is required to convey information regarding the tilt and position (not gps) of one particular iphone to another. Could 2 iphones send and receive this information simultaneously? What about 3 iphones? I'm interested in an application that is able to simultaneously send and receive and make conditional decisions based on this information received all within a half a second-ish.
Any shot this is possible? If so, is bluetooth or wifi better?
Thanks a ton,
Jake
This is currently not possible without an intermediate server. (Without a jailbreak, which would make it possible, but extremely difficult)
I'm assuming your purpose is gaming, in which case, the latency associated with a trip to a server and back over a cellular data network, is likely to take too long for any satisfactory gaming experience. I don't believe it would be within half a second.
This will be possible via Bluetooth in the upcoming 3.0 iPhone software, but that is still under NDA, so you are not likely to be able to get any reliable performance numbers until it is released. If I were guessing, I would certainly guess that the latency associated with a direct Bluetooth connection would be FAR under half a second.
All you've got as an option right now is Wi-Fi or the Cell Network. If you use Bonjour over Wi-Fi, you'd have latencies in the milliseconds, but all the phones would have to be connected to the same access point. Take a look at the WiTap example.
It is definitely possible, you'd want to connect your peers over WiFi for best performance and reliability, but Bluetooth would be ok as long as your data packets were constrained to small sizes (< 1k). Check out this documentation and sample code to see how to access UIAccelerometer:
http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UIAccelerometer_Class/Reference/UIAccelerometer.html
http://developer.apple.com/iphone/library/samplecode/AccelerometerGraph/index.html#//apple_ref/doc/uid/DTS40007410
The trick is that the update frequency is controlled in part by the systems needs, so there may be a window (while the system is attempting to update device orientation) wherein your application receives no updates.