Running Bluetooth (BLE) tasks in background, with React Native

The correct way to implement such a solution with a BLE accessory would be to use the Core Bluetooth Background Processing mechanism to wake up or launch your app when there is an activity. Depending on your use case and the delay you are able to accept, you would either keep a constant connection between the phone and the accessory, and the accessory would notify on a characteristic (fast but battery expensive), or the two would stay disconnected, and on a trigger condition, the accessory would start advertising, causing the app to connect and then they could do what needs to be done (will take longer but more power efficient)

How to implement this is explained here: https://developer.apple.com/library/archive/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html#//apple_ref/doc/uid/TP40013257-CH7-SW1

The document references native code. How to implement this in React Native will be left as an exercise.

Yep, useful docs for sure [@Gualtier Malde](https://developer.apple.com/forums/profile/Gualtier Malde) – I came across those already. It seems the RN implementation is the challenge I was particularly looking to solve, and seeing how I can call those methods from React Native, or design the native code correctly and then expose those methods to my React Native via RCT_EXPORT_METHOD (I'm not familiar with native iOS programming, so while I understand the docs in principle, I'm quite confused as to how to go about implementing that, and what methods I need to create & call from my React Native code base).

Any guidance on the specific implementation would be helpful. I know I have to use CBCentralManagerDelegate, and specific methods like peripheral:didDiscoverServices:, but I frankly have little idea on how to use those in context, so I'm trying to figure that out.