May 2014 - Bluetooth-dev - lists.apple.com

Unexplained loss of connectivity with Multipeer Connectivity
by Richard Lipes 16 May '14

16 May '14

Summary: I downloaded project from https://github.com/mxstrand/iOS_Bluetooth_App and have been running it with Bluetooth only (WIFI turned off) on two iPods. The project is described reasonably completely at http://strandcode.com/2013/09/29/breaking-down-bluetooth-in-objective-c-and…. When I run the apps on two iPods, I find (sometimes even before the alerts appear) that one of the iPods receives a call in session:peer:didChangeState: notifying it that connection has been lost to the other peer. After this event and after pressing OK on both alerts, the peer receiving the call cannot control the bubbles on the other peer; however, the peer NOT losing the connection can still control the bubbles on both iPods. In addition, the peer losing the connection seems to have an earlier timestamp about half the time (and correspondingly a later timestamp about half the time), so I assume the loss of connection is not correlated with the timestamp order. This loss of connectivity appears to be a bug, and no explanatory error message accompanies it. Steps to Reproduce: 1. Downloaded project from https://github.com/mxstrand/iOS_Bluetooth_App 2. Compile and load app onto two iPods with IOS 7.1 (latest iOS update) and separated by 1 foot. 3. Run app on two iPods which have Bluetooth ON and WIFI OFF. 4. Each of the apps connect to the other. 5. One of the apps will lose the connection to the other, which appears to me to be a bug. Expected Results: Until step 5. occurs, moving the bubbles on one peer will exactly control the movement of the bubbles on the other peer. Actual Results: When step 5. does occur, moving the bubbles on the peer that has not lost the connection will exactly control the movement of the bubbles on the other peer. However, moving the bubbles on the peer that has lost the connection has no effect on the movement of the bubbles on the other peer. Version: iOS 7 for iPods Notes: Description of the project is given at http://strandcode.com/2013/09/29/breaking-down-bluetooth-in-objective-c-and… _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: iOS 7.1.1 iBeacon Dropout Issue?
by Falko Richter 16 May '14

16 May '14

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Re: Is there a good overview of key exchange - with examples?
by Spero Koulouras 16 May '14

16 May '14

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RE: Is there a good overview of key exchange - with examples?
by Mozhaev Sergey-BDP687 16 May '14

16 May '14

Hi Roland, There are a number of "Message Sequence Charts" chapters in the Bluetooth spec: Volume 2, Part F Volume 3, Part H, 5 Appendices, 5.3 Volume 6, Part D I guess the 2nd one is what you need. Best Regards, Sergey -----Original Message----- From: bluetooth-dev-bounces+bdp687=motorolasolutions.com(a)lists.apple.com [mailto:bluetooth-dev-bounces+bdp687=motorolasolutions.com@lists.apple.com] On Behalf Of Roland King Sent: Friday, May 16, 2014 3:46 PM To: Bluetooth "<bluetooth-dev(a)lists.apple.com>"@il06exr01.mot.com Subject: Is there a good overview of key exchange - with examples? Is there somewhere a good, detailed, description of the entire process of key exchange all the way to devices having the AES keys they need, with examples of actual sequences? I've picked around the BT specs but I'm finding bits of information here, bits there and get the feeling there's an expectation the reader already knows what's going on. I'm particularly interested in how Just Works, Passkey and OOB start the process off. Google hasn't helped much here. _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/bdp687%40motorolasolu… _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Is there a good overview of key exchange - with examples?
by Roland King 16 May '14

16 May '14

Is there somewhere a good, detailed, description of the entire process of key exchange all the way to devices having the AES keys they need, with examples of actual sequences? I've picked around the BT specs but I'm finding bits of information here, bits there and get the feeling there's an expectation the reader already knows what's going on. I'm particularly interested in how Just Works, Passkey and OOB start the process off. Google hasn't helped much here. _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Replacement for deprecated registerIncomingDataListener:refCon:?
by Jeff Johnson 14 May '14

14 May '14

According to the documentation for -[IOBluetoothDevice openL2CAPChannelAsync:withPSM:delegate:], "The L2CAP channel open process will not complete until the client has registered an incoming data listener on the new channel. This prevents a situation where the channel succeeds in being configured and opened and receives data before the client is listening and is ready for it." However, I can see no way to register an incoming data listener, other than to use deprecated API. From IOBluetoothL2CAPChannel.h: /* Deprecated API */ @interface NSObject( IOBluetoothL2CAPChannelDeprecated ) - (IOReturn)registerIncomingDataListener:(IOBluetoothL2CAPChannelIncomingDataListener)listener refCon:(void *)refCon DEPRECATED_IN_MAC_OS_X_VERSION_10_5_AND_LATER; Is there a non-deprecated replacement for this method, or some other way to register an incoming data listener on a channel? -Jeff _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: CBPeripheral's discoverServices Fails After 3-6 Reconnections
by Caylan Larson 14 May '14

14 May '14

A few other notes. The CBCentralManager is running on another thread like so: dispatch_queue_t centralQueue = dispatch_queue_create(SemiCBConnectionManagerQueue, DISPATCH_QUEUE_SERIAL); _cbManager = [[CBCentralManager alloc] initWithDelegate:self queue:centralQueue options:nil ]; I profiled the app when it had reconnection issues. Even though the services are not found, the sensor can still respond with peripheralDidUpdateRSSI. Here's a sample of the profiling: Running Time Self Symbol Name 5.0ms 2.4% 0.0 _dispatch_mach_invoke 5.0ms 2.4% 0.0 _dispatch_queue_drain 5.0ms 2.4% 0.0 _dispatch_mach_msg_invoke 5.0ms 2.4% 0.0 _dispatch_client_callout4 5.0ms 2.4% 0.0 _xpc_connection_mach_event 4.0ms 1.9% 0.0 _xpc_connection_call_event_handler 3.0ms 1.4% 0.0 -[CBXpcConnection handleConnectionEvent:] 2.0ms 0.9% 0.0 _xpc_dictionary_look_up 1.0ms 0.4% 0.0 -[CBXpcConnection nsDictionaryFromXpcDictionary:] 1.0ms 0.4% 0.0 xpc_dictionary_apply 1.0ms 0.4% 0.0 _xpc_dictionary_apply_node_f 1.0ms 0.4% 0.0 _xpc_dictionary_apply_apply 1.0ms 0.4% 0.0 __49-[CBXpcConnection nsDictionaryFromXpcDictionary:]_block_invoke 1.0ms 0.4% 0.0 -[CBXpcConnection nsObjectWithXpcObject:] 1.0ms 0.4% 0.0 +[NSUUID allocWithZone:] 1.0ms 0.4% 1.0 DYLD-STUB$$__destroy_helper_block_183 1.0ms 0.4% 1.0 __62-[CBXpcConnection initWithDelegate:queue:options:sessionType:]_block_invoke 1.0ms 0.4% 0.0 -[OS_xpc_object _xref_dispose] I hope this can help someone isolate a problem... Caylan > I am developing an elaborate industrial automation app for a large company > that reads from four (4) independent Bluetooth 4.0 sensors that are custom > manufactured for this specific application. We are seeing reconnection > issues after reconnecting to the sensors 3-6 times. > > My tests result in the same issues whether on iPad Air, iPad Mini, iPod > Touch, iPhone 5. All devices are running 7.1.1. Note: The issue is not > "Bluetooth Error 1309" however, I have seen it once or twice in my > testing. The reconnection issue is easily resolved by swiping up from the > bottom and turning Bluetooth off and then on again. The app does not need > a restart to benefit from this BTLE power cycling. > > I have tried to mitigate the issue with zero luck: > > 1. Aggressive retries of discoverServices using various NSTimers > > 2. Delaying scanForPeripheralsWithServices by using > retrievePeripheralsWithIdentifiers on subsequent reconnections. This > solution works for the 2nd connection and maybe 3rd connection, but no > difference than if I used a pure scan. (Ugh, how I wish this was the > solution...) > > Any ideas on how to make reconnections reliable? > > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/bluetooth-dev/devlists%40semireg.com > > This email sent to devlists(a)semireg.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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CBPeripheral's discoverServices Fails After 3-6 Reconnections
by devlists＠semireg.com 14 May '14

14 May '14

I am developing an elaborate industrial automation app for a large company that reads from four (4) independent Bluetooth 4.0 sensors that are custom manufactured for this specific application. We are seeing reconnection issues after reconnecting to the sensors 3-6 times. My tests result in the same issues whether on iPad Air, iPad Mini, iPod Touch, iPhone 5. All devices are running 7.1.1. Note: The issue is not "Bluetooth Error 1309" however, I have seen it once or twice in my testing. The reconnection issue is easily resolved by swiping up from the bottom and turning Bluetooth off and then on again. The app does not need a restart to benefit from this BTLE power cycling. I have tried to mitigate the issue with zero luck: 1. Aggressive retries of discoverServices using various NSTimers 2. Delaying scanForPeripheralsWithServices by using retrievePeripheralsWithIdentifiers on subsequent reconnections. This solution works for the 2nd connection and maybe 3rd connection, but no difference than if I used a pure scan. (Ugh, how I wish this was the solution...) Any ideas on how to make reconnections reliable? _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re-connecting to a paired device
by Thomas Engelmeier 12 May '14

12 May '14

Hi, I have an application running on Mavericks that connects to TI SensorTags. I have problems to reconnect to an paired and connected periperial. The MBP I use has no BLE compatible BlueTooth interface, so I use an USB Broadcom interface. It works fine in the following setting: - When no tag is paired, the app is started, I start scanning when centralManagerDidUpdateState: gets called with CBCentralManagerStatePoweredOn and then I turn on the SensorTag, everything works fine. - in centralManager:didDiscoverPeripherial:, I try to connect to the periperial - In centralManager:didConnectPeriperial:, I retrieve and save the device UUID for reconnecting Now when the app crashes / exits / gets killed by Xcode, the sensor tag keeps connected (visible in the Bluetooth status bar item). The SensorTag remains also visible in the Bluetooth explorer „Bluetooth status“ window as „active“. When I relaunch, I call [centralManger retrieveConnectedPeripherials] and [centralManager retrievePeriperialsWithIdentifier:] and get an a.) centralManager:didRetrievePeripherial: gets invoked with all UUIDs I feed in, none of them have a name set, and all are disconnected (INCLUDING the one I paid just before) b.) centralManager:didRetrieveConnectedPeripherial: gets invoked with an empty array I’d expect b.) to return the (visible in the menu bar) connected, paired peripheral. When I turn the Bluetooth interface off and on again, the app starts scanning on the „power on“ transition, discovers the SensorTag and everything works fine.. What’s going wrong??? TIA, Thomas _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Re: Bluetooth iAP file transfer and HFP simultaneously?
by Matthias Ringwald 08 May '14

08 May '14

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