TN 3115 states that apps that do not use AccessorySetupKit will loose the ability to launch into the background to service bluetooth in iOS26. Starting in iOS 26 and iPadOS 26, only apps that use AccessorySetupKit to setup Bluetooth accessories will be relaunched. Is there any more information regarding this? Will it affect any app under iOS26 or only those build against the iOS26 SDK? My app (dev build) is still relaunched, even though I'm running iOS26, so I wonder if there are any more conditions checked.

My team has an app that uses BTLE heavily, and has been doing so successfully, including no issues continuing to receive data in the background and updating things in the app (for recording workouts). We have a BTLE write queue that only tries to write when the CBPeripheral.canSendWriteWithoutResponse property is true, or when we get the notification from the system in peripheralIsReady(toSendWriteWithoutResponse:). This is used as a means to rate limit data transfer, as we transfer files, as well as require that packets always arrive in the correct order due to blob encoding. However, we had a new requirement come in to periodically write data out to a connected peripheral. I noticed that as soon as the app was in the background, despite other delegate callbacks coming in, like didRecieveUpdatedValue:, neither the property canSendWriteWithoutResponse nor the delegate callback were called any longer. This meant our write queue didn't think it had permission to write, and packets would just stack up. The failure to deliver these updates didn't occur immediately after backgrounding, but did within 2-5s of backgrounding. If, when in the background, I ignore the changing of that property, and instead just write the data to the peripheral, it works! Can anyone explain why, despite other CBPeripheral callbacks happening when in the background, this one does not?

When our Bluetooth device is scanned and a connection is initiated through the app on the iPhone 17, the air log shows that the iPhone sends an LL_LENGTH_REQ to execute the Data Length Update Procedure. However, our peripheral does not support the Bluetooth LE Data Length Extension, so it responds with an LL_UNKNOWN_RSP PDU with the UnknownType field set to LL_LENGTH_REQ. After receiving the LL_UNKNOWN_RSP, the iPhone 17 does not proceed with the subsequent Bluetooth LE service discovery process. The connection is maintained until the peripheral actively disconnects. Once the peripheral disconnects and continues broadcasting Bluetooth signals, the iPhone 17 repeatedly tries to connect to the peripheral and executes the aforementioned process, even if the app has been terminated. According to the Bluetooth 4.2 core specification ([Vol. 6] Part B, Section 5.1.9), which can be found here: https://www.bluetooth.com/specifications/specs/core-specification-amended-4-2/, the iPhone should accept the LL_UNKNOWN_RSP and terminate the Data Length Update Procedure after receiving it, proceeding with the subsequent operations using the default minimum parameters. Phenomenon: When the app calls the - (void)connectPeripheral:(CBPeripheral *)peripheral options:(nullable NSDictionary<NSString *, id> *)options method, the connection result callback is never received. After a period of approximately 10 seconds, it fails with a callback, displaying the message: central did fail to connect to peripheral: <TY : 45E4A697-31AE-9B5A-1C38-53D7CA624D8C, Error Domain=CoreBLEErrorDomain Code=400 "(null)">.

Hello, I am working on iOS app acting as a central that connects to a peripheral which triggers bonding on connection. The pairing is successful on the first connection and after resetting the peripheral (and forgetting the device in Bluetooth Settings). It fails, however, after this devices is forgotten in the Bluetooth Settings at DHKey check, but the peripheral remains turned on. The peripheral is a linux device using BlueZ. This issue does not happen with Android device. Steps: Connect with the peripheral in the app using Core Bluetooth for the first time. Accept the pairing prompt. Bonding is successful and the peripheral is under MY DEVICES in Bluetooth Settings. Forget the device in Bluetooth Settings. Connect with the peripheral in the app using Core Bluetooth. Pairing prompt pops up repeatedly. Sometimes it pops up once, but the pairing is not successful as the device is not present under MY DEVICES. Connect with the peripheral in the app using Core Bluetooth another time. Pairing prompt still shows app. Restarting the peripheral fixes it and central iOS device is able to pair again. Sharing a screen shot from nRF Sniffer for SMP packets which indicate DHKey check failing. I was not able to attach whole log files because of size, let me know if needed I can share them in a different way somehow. Is there anything different in the flow between pairing for the first time and after forgetting the device?

FB18383742 Setup 🛠️ Xcode 16.4 (16F6) 📱 iPhone 13 mini (iOS 18.0.1) ⌚️ Apple Watch Series 10 (watchOS 11.3.1) Observations As AccessorySetupKit does not request "Core Bluetooth permissions", when a watchOS companion app is installed after having installed the iOS app, the toggle in the watch settings for Privacy & Security > Bluetooth is turned off and disabled After removing the iPhone associated with the Apple Watch, Bluetooth works as expected in the watchOS app Upon reinstalling the iOS app, there's a toggle for Bluetooth in the iOS ASK app's settings and the ASK picker cannot be presented 🤨 From ASK Documentation: AccessorySetupKit is available for iOS and iPadOS. The accessory’s Bluetooth permission doesn’t sync to a companion watchOS app. But this doesn't address not being able to use Core Bluetooth in a watch companion app at all 🥲 Reproducing the bug Install the iOS + watchOS apps Launch iOS app, tap "start scan", observe devices can be discovered (project is set up to find heart rate monitors) Launch watchOS, tap allow on Bluetooth permission pop-up watchOS app crashes 💥 Meanwhile, in the iOS app, there should be a log entry for 💗 CBCentralManager state: poweredOff and the ASK picker is no longer able to discover any devices The state of the device permissions: iOS app has no paired accessories or Bluetooth permission watchOS app's Bluetooth permission shown as turned off & disabled Remove the iOS app Relaunch the watchOS app Notice the CBCentralManager state is unauthorized Remove and reinstall the watchOS app Tap allow on Bluetooth permission pop-up watchOS app does not crash and CBCentralManager state is poweredOn The state of the watch permissions: Bluetooth is turned on & the toggle is not disabled Note that at this time the iOS app is not installed, there is no way to remove Bluetooth permission for the watch app. Reinstall + launch the iOS app Notice a warning in the log: [##### WARNING #####] App has companion watch app that maybe affected if using CoreBluetooth framework. Please read developer documentation for AccessorySetupKit. Notice a log entry for 💗 CBCentralManager state: poweredOn before tapping start scan Tap start scan and observe another log entry: Failed to show picker due to: The operation couldn’t be completed. (ASErrorDomain error 550.) ASErrorDomain 550: The picker can't be used because the app is in the background. Is this the expected error? 🤔 The state of the iOS permissions: The app's settings show a Bluetooth toggle normally associated with Core Bluetooth, but the app never showed a Core Bluetooth pop-up The iOS ASK app now has Core Bluetooth permission 😵‍💫 Following up with Apple This is a known bug that should be fixed in watchOS 26 when Bluetooth permissions for watch apps can be set independently of the iOS app. I've yet to test it with watchOS 26. See repo for the same post with screenshots of the settings and demo code reproducing the bug: https://github.com/superturboryan/AccessorySetupKit-CoreBluetooth-watchOS-Demo

mac/ios acts as a BLE client. After successfully establishing a BLE connection, it sends large amounts of data to the peer device. After sending data for a period of time, the system does not return peripheralIsReadyToSendWriteWithoutResponse for a long time, causing the data transmission to stall.

I'm experiencing intermittent failures when executing APDU (Application Protocol Data Unit) commands through Core Bluetooth to communicate with external secure elements. The communication flow involves establishing a BLE connection, discovering services and characteristics, and then sending structured APDU commands for card management operations. While the initial connection and characteristic discovery work reliably, I'm encountering inconsistent behavior during APDU command execution where commands either timeout, return unexpected response codes, or fail to complete the expected transaction sequences. The issue appears to be more prevalent when sending multiple APDU commands in rapid succession or when the commands involve cryptographic operations. I've implemented proper error handling and retry mechanisms, but the failures seem to occur at the Core Bluetooth level rather than in my application logic. The peripheral device responds correctly to the same commands when tested with other platforms, suggesting the issue might be related to iOS-specific BLE behavior or timing constraints. I'm using standard Core Bluetooth APIs (CBPeripheral, CBCharacteristic) with proper delegate implementations and have verified that the peripheral remains connected throughout the operation. Has anyone encountered similar issues with APDU command execution over BLE on iOS, and are there any known workarounds or best practices for ensuring reliable command delivery and response handling?

After the macOS Sequoia update, my app seems to have an issue with Bluetooth communication between macOS and iOS that uses CoreBluetooth for Central-Peripheral communication. Setup: The iPhone (in my case: iPhone 14 Pro with iOS 18.0 (22A3354)) acts as the Central, and the Mac (in my case: 14" MacBook Pro 2023 with macOS 15.0 (24A335)) as the Peripheral. I’ve implemented a mechanism where the Central (iPhone) sends a message to the Peripheral (Mac) every 15 seconds to keep the connection alive (Because it needs to wait for notify characteristic updates). I never noticed this kind of issue before, but with macOS Sequoia I get it permanently. Issue: The connection drops unexpectedly after a period of time (sometimes 20 seconds, sometimes a few minutes) with CBErrorDomain - code 6: The connection has timed out unexpectedly. Sample Code: Peripheral (Mac): ContentView (Peripheral).txt ContentViewModel (Peripheral).txt Central (iPhone): ContentView (Central).txt ContentViewModel (Central).txt Reproduce: I attached sample code including the Central-Sample (for iPhone) and Peripheral-Sample (for Mac). Just run the Peripheral-Sample (after granting Bluetooth permissions). Then run the Central-Sample and select the Mac device in the list After selecting it should connect, discover the service & characteristic and should start writing messages to it. After some time the func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: (any Error)?) {should get called with timed out unexpectedly error. Could anyone please look into this issue and advise on whether there’s a known bug or any workaround? Any guidance would be greatly appreciated, as this impacts the stability of Bluetooth communication between the devices. Thanks in advance. Logs: I also ran the console.app during this issue which got these errors (if this is helpful): console_logs.txt

I'm developing an application using the accessory setup kit (BLE) on iOS 18+. An important aspect of the connection process is being able to find and choose the correct device. I noticed on iOS 18.2 that I was able to both scroll through the discovered accessories as well as view the advertised name. However, after upgrading to 18.7.2, only a single device is viewable and the advertised name is no longer available. Is there a trigger for this feature that I need to enable or was this "multiple discovery" feature removed? If so, why?

Hi All, I'm working on an app that needs to connect to BLE device and on defined schedules download data from the device. the amount of data is segnificant and might take around a minute to download. we tought about utilizing both state restoration and preservation for app waking and scheduling (triggered by the ble peripheral) and BGTaskScheduler to schedule a task that will handle a long running task to manage the full data download. now, will this solution in general valid? isnt it a "hack" that goes around the 10s limit that state restoration enforces? i know there are limitations for BGTask (like when it runs, it might be terminated by the system etc) but considering that, can we proceed with this approach without breaching apple guidelines? thank you in advance!

I am pretty sure iOS 13.4 (beta and later) did support Coded PHY (Long Range). Tested devices are iPhone SE2 and iPhone 11 Pro. However, it seems iOS 14 removed the support of Coded PHY, accidentally or on purpose, I don't know? The same PHY update request returns "1M PHY" in iOS 14, but "Coded PHY" in iOS 13 (13.4 beta and later). Anyone knows why? Samson

My phone turns or gets connected to Beats, Aipods max 2, and sometimes the Marshall Bluetooth device but it keeps triggering the automation for “When Connected To Bluetooth” - My Car tried deleting and recreating the automation and it’s still buggy.

First, our app communicates with our blood glucose monitor (CGM) using Bluetooth Low Energy (BLE). On an iPhone 14 Pro with iOS 26.0.1, Bluetooth communication works properly even when the app is in the background and locked. Even if the phone and CGM are disconnected, the app continues to scan in the background and reconnects when the phone and CGM are back in close proximity. It won't be dormant in the background or when the screen is locked. This effectively ensures that diabetic users can monitor their blood glucose levels in real time. However, after using iOS 26.0.1 on the iPhone 17, we've received user feedback about frequent disconnections in the background. Our logs indicate that Bluetooth communication is easily disconnected when switching to the background, and then easily dormant by the system, especially when the user's screen is locked. This situation significantly impacts users' blood glucose monitoring, and users are unacceptable. What can be done?

Application has specified the bluetooth-central background mode. Peripheral Device(BLE) is connected to the iPhone. Application will initiate a request 'retrieveConnectedPeripheralsWithServices' along with list of services to scan for. Application will receive a list of peripherals connected to the system whose service UUID's match. From the list of peripherals, application will initiate a request 'connectPeripheral' with the interested peripheral along with the option set to 'CBConnectPeripheralOptionEnableAutoReconnect'. This option is available from iOS 17+. CBConnectPeripheralOptionEnableAutoReconnect - This option will help in reconnect back to peripheral when peripheral becomes available. (Turn OFF and Turn ON) How do we achieve the same thing in earlier IOS version

We are working with Bluetooth peripherals using CoreBluetooth, and I've noticed that the CBPeripheral.name property seems to be cached. Has anyone else encountered this behavior? Is this caching expected behavior in CoreBluetooth? Is there a recommended way to force refresh or invalidate the cached name? Most importantly: Is there a reliable method to get the most accurate and up-to-date name of a peripheral?

[sysdiagnose_2025.10.01_18-29-27+0800_iPhone-OS_iPhone_23A341] I got sysdiagnose from my app user.He can't pair his bluetooth peripheral. in the sysdiagnose,I found this: device AC:7A:94:85:47:F4 is already paired, with a different irk (old:F5 C9 4F 5A 4E BE D0 20 0A 1F F7 DC 3A 89 E0 3A new 4A 8A 00 4C FF D0 CE 7B 61 13 FA B3 84 F4 65 29 ). Unpair first and then restart pairing. (status=65535) but there is no device in his iphone's SYSTEM BLUETOOTH PREPHERAL LIST. I don't know how to delete the irk info when you can't find it in SYSTEM BLUETOOTH PREPHERAL LIST. PLEASE answer me. THANKS.

Using an iPhone Pro 12 running iOS 26.0.1, with AirPods Pro 3. Camera app does capture video with what seems to be "Studio Quality Recording". Am trying to replicate that SQR with my own Camera like app, and while I can pull audio in from the APP3 mic, and my video capture app is recording a 48,000Hz high-bitrate video, the audio still sounds non-SQR. I'm seeing bluetoothA2DP , bluetoothLE , bluetoothHFP as portType, and not sure if SQR depends on one of those? Is there sample code demonstrating a SQR capture? Nevermind video and camera, just audio even? Also, I don't understand what SQR is doing between the APP3 and the iPhone. What codec is that? What bitrate is that? If I capture video using Capture and inspect the audio stream I see mono 74.14 kbit/s MPEG-4 AAC, 48000 Hz. But I assume that's been recompressed and not really giving me any insight into the APP3 H2 transmission?

PLATFORM AND VERSION Model - iPhone 13 Pro Max (Potentially for other models also) OS - iOS 26 DESCRIPTION OF PROBLEM : BLE discoverability (advertising) is not working on iOS 26 but works reliably on older iOS versions. Details: Our app acts as a Bluetooth peripheral. When advertising, the app only adds CBAdvertisementDataLocalNameKey in advertisement data. Format of local name - "NTDI:103202400001" We have observed that in iOS 26, the local name is getting truncated. This breaks the parsing logic in our IOT device central code, which expects the full local name to be present. We have also observed that some extra data is getting added to the advertisement data by the OS. As of now, updating the IOT device logic for parsing is not possible. STEPS TO REPRODUCE Create an instance of CBPeripheralManager. Start advertising with a local name with the format "NTDI:103202400001" Capture the advertisement data using a Bluetooth sniffer tool. Observe that the local name is getting truncated Legacy ADV_IND as received by IoT device (truncated name): HCI Event: LE Meta Event (0x3e) plen 27 LE Advertising Report (0x02) Event type: ADV_IND (0x00) Data length: 15 Flags: 0x1a TX power: 12 dBm 12 09 4e 54 44 49 3a 31 30 ..NTDI:10 RSSI: -47 dBm Only partial Local Name (“NTDI:10…”) is present in this primary PDU. Is it possible to avoid the extra data introduced by iOS or avoid local name truncation?

Our app scans Bluetooth in the background. However, the iPhone 17 device does not scan in the background. ios 26 Is there anything I need to do?

Hello. Is there a solution to the issue where Core Bluetooth does not run in the background on the iPhone17? https://developer.apple.com/library/archive/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html The bluetooth-central Background Execution Mode When an app that implements the central role includes the UIBackgroundModes key with the bluetooth-central value in its Info.plist file, the Core Bluetooth framework allows your app to run in the background to perform certain Bluetooth-related tasks. While your app is in the background you can still discover and connect to peripherals, and explore and interact with peripheral data. In addition, the system wakes up your app when any of the CBCentralManagerDelegate or CBPeripheralDelegate delegate methods are invoked, allowing your app to handle important central role events, such as when a connection is established or torn down, when a peripheral sends updated characteristic values, and when a central manager’s state changes. Although you can perform many Bluetooth-related tasks while your app is in the background, keep in mind that scanning for peripherals while your app is in the background operates differently than when your app is in the foreground. In particular, when your app is scanning for device while in the background: The CBCentralManagerScanOptionAllowDuplicatesKey scan option key is ignored, and multiple discoveries of an advertising peripheral are coalesced into a single discovery event. If all apps that are scanning for peripherals are in the background, the interval at which your central device scans for advertising packets increases. As a result, it may take longer to discover an advertising peripheral. These changes help minimize radio usage and improve the battery life on your iOS device.