In previous iOS versions you could detect if the user had bluetooth enabled or not without actually prompting the user's permission to access bluetooth. In iOS13, CBCentralManager now prompts bluetooth permission just to check if they have bluetooth turned on or not, regardless of if the app is actually going to use bluetooth directly.
Our app uses Apple's multipeer connectivity framework to communicate between devices (peer to peer) which uses a combination of wifi and bluetooth, or just wifi if bluetooth is disabled, but that is slower, so we like to remind our users to turn on bluetooth for a faster connection. Using this framework does not actually require a permission prompt for the app to use bluetooth because Apple manages all of that in a closed box so our app itself doesn't use bluetooth or require a permission prompt to work, but Apple's multipeer framework works better if the user has bluetooth enabled.
We want to simply remind the user to enable bluetooth for a faster connection, but only if they don't already have it on. However just checking if it is enabled the old way now requires a bluetooth permission prompt even though we won't be using bluetooth in the app.
In iOS13 is there a new method for just checking if bluetooth is enabled or not that doesn't require a bluetooth permission prompt.
Related
Since the latest update (I think some time in December 2022), the built-in camera app on my Samsung Galaxy S21 asks for "Nearby devices" permission, and refuses to run if I don't grant it. By "Nearby devices" it means "Bluetooth". I don't know why it calls the permission
"Nearby devices": all other references to Bluetooth call it "Bluetooth",
and you can also access a nearby device using Wi-Fi or even NFC if the device
is close enough.
It doesn't actually need Bluetooth to take photographs, or even to record movies,
but you might have a Bluetooth microphone (I don't) and you might want to use
it to get better sound quality when recording a movie.
Of course the Android best practice advice at
https://developer.android.com/guide/topics/permissions/overview
is not to ask for runtime permissions unless and until you need them,
but Samsung aren't doing that.
I don't want the camera app to announce my presence by probing the Bluetooth headset of
anyone who happens to be near me, and they might regard such an action as intrusive.
So I don't want to give the camera app its nearby devices permission, but it won't
run at all without it.
So how do I get the camera app to run without accessing Bluetooth?
I found some workarounds for this. If your device supports it, you can download Expert Raw from the Galaxy Store. This will take still photos without requiring "Nearby devices" permission. However it doesn't seem to be able to do selfies because there seems to be no way to switch cameras, and it can't do movies or many of the extra tricks that the full camera app can do.
Another option is to run the camera app with Bluetooth disabled. Then it can have its "Nearby devices" permission, but it can't use it. The problem with this is that if you use Bluetooth at other times you have to remember to disable it and enable it.
So I wrote a tiny app which disables Bluetooth, runs the camera app, and restores the previous enabled or disabled state of Bluetooth when the camera app exits. I put this on my home screen instead of the camera app: it has the same icon. You have to remember to exit properly from the camera app using the Back button: the Home or Recents buttons leave my app and the camera app sitting on the task's back stack, so my app doesn't get to run and restore the Bluetooth state.
The app is available on github here in case anyone else wants to use this solution.
Am developing a Galaxy Watch Active2 app. The app advertises a custom Bluetooth Low Energy service. This is in addition to the advertising profile the watch has out of the box for pairing with a phone. I would like to know if it is possible to disable the out-of-the-box advertiser? The reason is that the additional profile is making my remote device connection slower and less predictable. Anyone knows how to do that?
I'm trying to establish a connection between my PC running Ubuntu and my iPhone via Bluetooth automatically when it becomes available, after being manually paired beforehand. I've seen this to be possible with certain peripherals, mainly audio. For example, my phone will automatically connect to a Bluetooth speaker when it is turned on and Bluetooth is active on my phone; another example is my phone automatically connects to my car's radio system via Bluetooth when I turn the car on.
I'm not able to connect my phone to my PC without first initiating the connection from the smartphone's Bluetooth menu. I'm thinking that I could possibly write an application for the PC to attempt to connect to the device every few minutes or something, but it seems that the phone needs to be the device to initiate the connection.
The only information that I need for what I'm trying to do ultimately is that the devices can pair successfully. Essentially I'm trying to build a sort of proximity trigger between my phone and my PC without using Wi-Fi and GPS - I can't use these for some specific reasons.
Is there any way to make this happen?
Yes this should be doable as long as you use the Background Processing feature for iOS apps. In the example I'll give below, we'll have the PC be the peripheral and the phone be the central, but you can really have it working either way. You will need to do the following:-
First initial connection needs to be performed in the foreground (this is due to iOS's background limitations).
On the iOS side, you need an application that acts as a central that scans and connects to the remove device (check this example as a starting point).
Upon connection, you need to bond with the PC. Bonding is important as it will prevent you from having to do the pairing again in the future. However, pairing/bonding is managed by the iPhone's OS so you cannot write it in your application, so the workaround is to have an encrypted characteristic on the PC side that will force the iPhone to bond (this is covered later).
On the PC side, you need to have a BlueZ script that acts as a peripheral that is always advertising. You can do this using bluetoothctl (check the examples here and here).
Before you start advertising, you need to have a GATT server on the PC side (to do this, check this example).
When registering characteristics, ensure that one of them has the encrypt-read property (you can find a full list of the properties here).
Now when you attempt to read this characteristic from the iOS side, the two devices should bond (make sure that your PC is bondable which you can do this via these commands).
Once the devices are paired, your iOS app needs to be working in the background constantly scanning and attempting to connect to the same peripheral (have a look at this and this example).
You can find more useful information at the links below:-
Getting started with Bluetooth Low Energy
The Ultimate Guide to CoreBluetooth Development
How to manage Bluetooth devices on Linux using bluetoothctl
We've got a use case in which a BLE connection is used to do the basic configuration of an embedded device via an Android app (later also via an iPhone app). The embedded device runs Linux and thus uses BlueZ as Bluetooth stack.
Using the DBus-API of BlueZ, bonding is made possible by making the device pairable, discoverable, and activating advertising. After bonding the apps can access the GATT services and characteristics
(which require bonding to be read/written) on the embedded device.
After the setup is done the bonding of the device (running the app) that managed the setup process, is supposed to be removed. In order to do that we call RemoveDevice() of org.bluez.Adapter1.
The BlueZ documentation states the following
void RemoveDevice(object device)
This removes the remote device object at the given
path. It will remove also the pairing information.
Still the app is able to access the GATT characteristics afterwards.
If bluetoothctl is used to check the list of paired devices, the list is not containing that device anymore though. Before calling RemoveDevice() the bonded device was visible there.
If bluetootd is stopped and restarted the app is no longer able to read/write the GATT characteristics, but needs to re-bonded before doing so.
I can neither find any further information in the BlueZ documentation nor can I find anything about this topic searching anywhere else.
Is this intended behavior or is this a bug? Does "remove pairing information" also mean "remove bonding information"? If this is intended behavior, how do we properly terminate bonding with a device?
Should I use the BlueZ Management API instead of the BlueZ API? I'm not sure about this as multiple source state that the DBus-API is the way to go.
RemoveDevice() indeed removes the bonding information as well. So you have to disconnect first and then call RemoveDevice(). The next time you connect the bonding information will be gone.
However, note that if you only make use of encrypted characteristics, you can still connect and discover services. Only once you start reading/writing the encrypted characteristics will Bluez check if you are bonded.
I was wondering if there's any way that I can control BLE device pairing specific to my app running on mobile device?
I do not want to write my own bluetooth profile so that only my app can talk to the BLE device instead i want to standard profiles available in BLE device but when it's paired to my phone, only my app should be able to communicate to it and none of the other apps should be able to communicate.
No don't do that.
If you MUST then you should encrypt your data with a key only your app knows.
Bluetooth Low Energy is supposed to be open and free for all.
What is the purpose for you to block others? Preventing them to block your service?
Then use some pre-shared key to verify that it's your app in both sides and close the connection if it's not.