I am writing an app for iOS that needs to receive data from a Bluetooth device (classic Bluetooth, not BLE). I need a pretty fast data transfer, 1Mbit/s or faster if possible. This already works using SPP in Android.
Apple only supports some Bluetooth profiles as listed here: https://support.apple.com/en-us/HT204387 I think these profiles are the only ones supported without being in the MFi program. MFi is too difficult to deal with so I would really like to avoid it. SPP is of course not available.
Of these profiles, PAN and maybe A2DP and HFP seem likely to be usable for bulk data transfer. A2DP or HFP would be a hack as they are really not designed for non-audio data. This seems to leave PAN.
How can an iOS app transfer data from a classic Bluetooth device using PAN? I would like the app to connect and somehow establish a data connection. This may be over IP (like tethering or reverse tethering using PAN) or non-IP. I want something which behaves a lot like the SPP profile, in other words a bidirectional serial link between the two sides.
Note: The Bluetooth device on the other side of this can do anything that is needed (I am writing the device firmware at the same time using a bluetooth stack, probably the TI dual-mode stack). Extra bounty if you can give me example of PAN tethering using any Bluetooth stack (TI, Synergy, dotstack etc).
See also: Is possible to communicate via Bluetooth PAN in iOS with tethered devices
Related
how to make iOS app with bluetooth?
I need an app which connects and exchange data via bluetooth with other devices, laptop for example.
Many packages for BLE and cant find for classic bluetooth
If you want to use the classic Bluetooth interface of an Apple iOS device, you have to comply with/accept Apple's MFi licensing programme (Made for iPhone/iPod/iPad), which is a major hurdle and the reason for the lack of corresponding libraries.
Short answer: you don't want classic Bluetooth for this. You want BLE. It supports everything you want for this kind of use case. See Core Bluetooth.
Much too long answer about classic Bluetooth and iPhones from my years building earbuds:
Continuing from Risto's answer, even with MFi certification (which requires adding an extra chip to your device, not just licensing), you still don't get general access to the BR/EDR ("classic") interface. You only get access to iAP2, which is an SPP-like serial protocol, but is not SPP. If you're porting from Android, you probably are using SPP, and sorry, that's just not available. You're going to need to switch to BLE.
MFi certification is a useful if you build an audio device that also needs a non-audio control channel. It makes it easy to ensure that both the audio connection and control connection are connected to the same device. This is extremely difficult to do with BLE. But iAP2 isn't a particularly nice protocol, and has weird corner cases. You should not go through the cost and trouble of MFi just to get a SPP-like serial protocol.
On iPhones, access to BR/EDR non-audio profiles is limited to the proprietary iAP2 and GATT over BR/EDR (which is less useful than it sounds since most chips don't support it). Classic audio profiles are limited to what Apple's audio frameworks support, which is not very flexible.
If you make a Bluetooth audio device, have a little extra room on your board, enough margin to add a chip to your BOM, and your SoC supports it, MFi is definitely worth exploring. You can improve the pairing experience marginally and it makes it a bit easier to manage an extra control channel. Plus, you get to add that "Made for iPhone" logo to your packaging. For hearing aids (which I have less experience with), I expect that MFi is a must-have today. From my casual investigation, it looks like it adds some really nice capabilities.
For everyone else, you want BLE.
I have a specific requirement to communicate an iOS device with a wifi/bluetooth enabled device. At this moment, I'm confused with some points and requires an expert advice.
Can I use adhoc wifi method for communicating? but in this case, can I connect to another network? On my research, I found no so I'm opting for Bluetooth.
If I go in bluetooth communication,
Do the device need MFI licensing or can we use classic bluetooth?
From few blogs I found out that Bluetooth low enrgy devices with 4.0 can be used to communicate with ios without licensing. Will this work?
PS: My requirement is to send strings of data to and fro from the ios and other wifi/bluettoth enabled devices.
An iOS device can only be connected to a single Wi Fi network at a time, so an Ad-hoc network connection probably won't work for you.
If you join the MFi program you can use the Wireless Accessory Configuration (WAC) feature to simply the process of connecting your device to the user's existing network.
If you use Bluetooth Low Energy/Bluetooth Smart/Bluetooth 4.0 then you don't need to go through the MFi program, but you are limited to iPhone 4S and later and iPad 3 and later. If you use "classic Bluetooth" (Say Bluetooth 2.1 Serial Port Protocol) then it will work with all devices but you need to go through MFi.
Bluetooth Low Energy isn't great for high data volumes (say video streaming) but is fine for smaller amounts of data (you talk about "strings" so it will probably be suitable for you).
The other advantage of BLE is that it is independent of the iOS device's Internet connection so the user can cary the BLE device around and maintain communication regardless of their WiFi connection.
I'm developing a stereo headset with Bluetooth using the classic profiles (HFP, A2DP, AVRCP) as one would expect Ina stereo headset. However, I want to deploy a remote control app for iOS, and use it simultaneously to the other classic links, but the dual-mode chipset I'm working with in my design does not behave as I'd expect;
The headset is setup as a peripheral, letting the iOS device act as central. As such, the peripheral advertise its BLE services (with my specific 128-bit UUIDs) and all is good. I can browse the peripheral from any central, but only when I'm not connected with classic profiles (e.g., while not streaming audio).
My device does not seem to be able to advertise BLE, while connected with HFP and/or A2DP! However, I have seen demos of the same chipset acting as BLE central, scanning and connecting to other BLE peripherals, while simultaneously streaming audio via A2DP. However, in that setup the device was acting as A2DP sink connected to an iPhone, while scanning/connecting via BLE to a third unit acting as BLE peripheral. Hence, not point-to-point with both Classic and Smart Bluetooth to the same device.
Is there a dual-mode constraint that one cannot act as peripheral while supporting/connecting to Bluetooth Classic profiles? And that only Central-mode is supported in that case?
FYI, I'm using CSR's 8670 chipset.
UPDATE
New answer added. My apologies for not clarifying/cleaning-up my previous answer until now -- time flies!
Well, after digging down into specs and trying to understand things more clearly, I've found the answers I was looking for, even though I would have preferred to more optimistic answers... ;(
Nevertheless, let's get to it; the Bluetooth spec for 4.0 (BLE) says that;
Dual-mode gadgets cannot act as BLE peripheral and advertise its
presence while still being connectable in "Classic" Bluetooth using
BR/EDR.
Furthermore, CSR source-code examples for the CSR8670 dual-mode chipset I'm using all behave in the same say; BLE advertisements as peripheral are disabled when any classic BT-link is connected. Instead, the CSR source code promote that the device should act as the BLE central instead, allowing other BLE peripheral units to advertise and connect to it, all fully doable while streaming audio (acting as A2DP sink).
This does not suite my setup at all since;
BLE centrals consume more power than BLE peripherals, and my device needs to conserve energy
The dual-mode "combo"-problem of combining a BR/EDR-device with BLE peripheral functionality just moved to the phone instead, which will not work any better since we cannot expect Apple (or anyone else) to violate the BLE spec.
Instead, the recommended approach is let my stereo headset skip BLE entirely and use GATT over BR/EDR instead, also known as advertising via "vanilla", which makes sense really; I mean, I already have an ACL-link setup between two devices, why should I need to kick any sort of discovery mechanism?
Again, the Bluetooth SIG comes in handy;
https://developer.bluetooth.org/TechnologyOverview/Pages/GATT.aspx
GATT and ATT are not transport specific and can be used in both BR/EDR
and LE. However, GATT and ATT are mandatory to implement in LE since
it is used for discovering services
So, the SIG says "yes" to using BR/EDR as transport for GATT, but the question then instead becomes; how can I then get access to that connected BR/EDR device from within my iOS-app, where the typical scenario is to use CBCentral to scan, discover and connect to a CBPeripheral? The answer is simple; you cannot, since iOS 7.0 does not (yet?) support GATT for BR/EDR;
https://www.bluetooth.org/tpg/showDeclaration.cfm?3A000A5A005C5344535D5414403B0C0D0E2405022413010E57503F202A5A72
So, to sum things up; if you want to have a peer-to-peer setup between two dual-mode Bluetooth devices, using BOTH Bluetooth Classic profiles AND Bluetooth Smart services/characteristics, you should use GATT over BR/EDR, which is no-go for Apple-devices, but might be supported by Android (don't know, will port app to Android eventually though, but regardless it's not a big deal for Android since worst-case will imply a fallback to SPP and a simple byte-protocol to do the work that I need to get done).
That's that. Hope that I've helped someone ;)
/Markus
You learn as long as you live, I suppose, and this question's answer is NOT that it's not supported which I claimed earlier (based on what I thought I knew).
The short and clean answer to dual-mode and headset development on CSR-chipsets is simply that it was a constraint in the CSR bluetooth stack on earlier SDKs.
The Bluetooth SIG has never not supported dual-mode acting as Peripheral while being connected via classic links to the same device. On the contrary, it clearly spec. how such interoperability should be carried out -- but that doesn't always mean that all BT-stack implementations out there are capable of such functionality.
Hence; Using the latest devtools and the latest Bluetooth firmwares/stacks from CSR has resolved all issues and dual-mode is now fully, and actually quite nicely I might add, supported on the CSR8670/75 chipsets.
I am also using the CSR8670 device.
It have it working. Both a BLE peripheral and audio.
You need to be using ADK 4.0.0 by CSR.
Bluetooth 4.1 and Bluetooth 4.0 are different. For what you said about Bluetooth 4.0 is correct, but your chip can do Bluetooth 4.1.
4.1 allows such connections.
I also added "Dual mode" flags to the advertising packet.
There are a few conditions, such as a connection Interval of at least 90 miliseconds highly recommended so you dont mess with the audio.
Good luck!
In reference to Dennis Mathews answer how do you specify Bluetooth Classic instead of LE on iOS? Is there a different api from Core Bluetooth Framework?
Joels there is a very clear way to use Bluetooth classic on iOS. It is with the External Accessory framework (it also includes direct hardware connections in addition to Bluetooth classic however).
You need to add the ExternalAccessory.framework and specify "App communicates with an accessory" in the required background modes inside your plist to get started. It should be noted however that with Bluetooth classic, the user must add your Bluetooth device from the System Bluetooth settings. It is only with Bluetooth LE that we are able to add devices from the app side.
Check out the docs on the External Accessory Framework
In response to your question regarding the MFi program, this should clarify:
I want to develop an iOS app that communicates with an MFi accessory. Do I need to join the MFi Program?
No. iOS app developers do not need to join the MFi Program. Everything app developers need is in the External Accessory Framework,
which is provided in the iOS SDK. To access the iOS SDK, please join
the iOS Developer Program: https://developer.apple.com/programs/ios/.
If you'd like to learn more, consult the MFi FAQ
If your external accessory doesn't need high bandwidth in the connection to iOS, and you wish to use (or must use) 2.x/classic BT, (instead of 4.x/LE/Smart, which is very low bandwidth but requires no MFi dancing) you may be able to communicate by emulating a BT HID keyboard in your accessory.
It's hardly optimal, especially since the HID reverse channel is pretty limited (I think to things like lighting the caps lock key in the basic keyboard configuration (HID page 7 mapping, if I recall correctly.) OTOH, if your primary task is to push data to the iOS device, sending the data as keystrokes would not be too awful. (and might even be seen as virtue during testing :)
HID devices can declare additional capabilities in table defined keymaps, but I'm not sure if an iOS app can get at those alternate mappings with sanctioned APIs.
Is it possible to pair an iDevice to an rs232-bluetooth adapter for the purpose of sending serial commands like it would through an iDevice dock connector to rs232 (just like the Redpark Serial Cable does)? I ask because the company I work for is thinking of having an iDevice control one of our systems for demo. I know it doesn't relate to anything specific but any information would be greatly appreciated.
(See also iPhone to RS-232 via Bluetooth)
Bluetooth modules exists that support MFi (Made For iPhone) such as this one from connectBlue http://www.connectblue.com/products/bluetooth-products/bluetooth-modules/bluetooth-iphone-ios-accessory-module-obs414/ So the standard iPhone Bluetooth stack can make a SPP/RFCOMM connection to that device. That device could be added to a board along with RS232 level-conversion etc... And thus success.
I don't know whether someone sells such a device. The RS232 device that connectBlue sells seems not to support MFi, http://www.connectblue.com/products/bluetooth-products/bluetooth-devices/bluetooth-rugged-serial-port-adapter-rbs433/
Not really. The GameKit is one way to access bluetooth in iOS, but it is very limited in what that API allows you to do.
Depending on what you are building, you might be able to use the Apple Made for iPod program, but it's probably a long shot.
http://developer.apple.com/programs/mfi/
The best way to go is probably to design a device that connects via WiFi. I've gone this route, and it worked out well. If you must interface with something with an RS-232 interface, you might design an intermediary "adapter" that connects via WiFi to the iOS device, and via RS-232 to the other device.
If you don't have a need to distribute your app via the App Store, you can use Redpark's iOS serial cable: http://redpark.com/c2db9.html. (Disclaimer, I've never tried one, but according to someone at Redpark, jailbreaking is not required, you just can't distribute your app on the app store.)
You could design a small dongle that attaches via the dock connector, and broadcasts over bluetooth to your other device.
Or you could use WiFi instead of bluetooth... perhaps communicating over WiFi to something that's physically plugged into whatever you want to control.
I worked on a jailbroken app which used BTStack to communicate with a serial device. You might be able to use this for your demo.
If you're still looking to use bluetooth, this helped me out alot to facilitate the standard serial connection for prototyping without jailbreaking:
http://www.seeedstudio.com/depot/bleshield-based-on-bluegigas-ble112-module-p-1367.html
It works on the Bluetooth 4.0 enabled iOS devices and all of the schematic, boardfiles, firmware sources and the iOS App sources are available here:
https://github.com/michaelkroll/BLE-Shield