Can a BLE Central connect to BLE Peripheral on same iDevice? - ios

I've written an app that could (as a side effect) provide information to another app (not mine) running on the same iDevice. In order to do so, I'd need to make my app a BLE Peripheral providing the BLE service that the other app looks for. If I were to do this, would the other app be able to connect to my Peripheral app, even though it's running on the same iDevice?
I've only found one passing comment on the topic, in this Stack Overflow answer. It says: "Note that you cannot connect to your own device even if it acts as a peripheral" but I'm not ready to give up on the basis of one opinion. Is there any authoritative documentation that rules this out, or is this something people know from trial and error?

Related

ESP32 iPhone Bluetooth, just a general question

I'm writing some code (C++) for ESP32, to act as a BLE beacon. The problem is this: the iPhone doesn't send out its real MAC address, but does a random-generated MAC address, for security. The thing I'm confused about is how do you know if it's a device you've previously paired with?
So let's say I detect a new BLE MAC address, and looking at the manufacturer data I can determine it's an Apple device (first 2 bytes are "4C").
Now I need to know if I've previously paired with that device, so that I can allow the ESP32 to initiate an action (for simplicity let's just say turn on an LED). If that MAC address is in a list of known devices, then I can continue, and if not, I ignore it.
The problem is, if the iPhone is not giving up the real MAC address, the detected MAC address will never match anything. As this is a security situation I'm sure the algorithm for generating those MAC addresses is not known.
To be clear: this code is being written for the ESP32, not the iPhone.
It is in fact not possible to tell if a device has been previously seen, unless you pair and establish a bond with it. Once you pair with the device, long-term keys are exchanged and are used to quickly re-establish the connection.
This is by design. MAC addresses were originally unique, but this allowed tracking people and devices without their consent. You can read more about this in the following ESP-IDF guides:
GATT security server walkthrough
GATT security client walkthrough
So are you using esp32 as a beacon? This dose not involve any pairing or iOS MAC addresses. iOS will just be able to listen and the esp32 will not even know someone is "listening" to its broadcast.
Probably iOS application can store which services it is interested to hear to; may looks like pairing.. but it is a high level application managed technique and not any related to what BT standard calls pairing.

OBD2 BLE communication from iOS

I will be using OBD2 device to get data form a car. I don't have the dongle yet, but am reading into how things should be done. As far as I understand the device should be with BLE on and should scan for peripherals with some specific service.
For example I need to get the speed of the vehicle. How should I know what is the UUID of the service I am looking for and what are the UUIDs of its characteristics and possibly some details about the data that should be received. For devices using GATT profiles for example they could be found here: https://www.bluetooth.com/specifications/gatt/services . But I don't find any such documentation for OBD2. I found this answer: here and the first one here. As far as I understand they suggest I need to look through all peripherals and all services there and try all characteristics to find the needed ones and distinguish them by the response. Is this the only way to do this? I found also this project: here where some UUID is used but I cannot understand where it comes from. Any suggestions how to get the needed UUID-s?

Publish IOS App to Appstore with SSID ( wifi) discovery/connect through app

I was trying to get a specific info before a IOS App development task which I searched but couldn't find anything relevant.
Wanted to know whether this requirement restricts (non compliance issue as per publish guidelines) the app to be published in App Store with features as below
User scans and lists all available wifi connections in a tableview
Selects one of the Wifi connection and connects on button click
Stores the password and SSID for future connections.
Would there be any compliance issue related to the same functionalities when submitting to IOS app store. One of my colleague have advised me about the same but not able to explain why? Which I tried to find out searching the internet, but too specific to find anything relevant. Deeply appreciate an Expert advise on this.
Thanks in advance.
I can't find anything in the Review Guidelines that would object your app idea: https://developer.apple.com/app-store/review/guidelines
A couple of areas where you should have a more detailed look:
2.5.1 Apps may only use public APIs.
2.5.9 Apps that alter the functions of standard switches, such as the Volume Up/Down and Ring/Silent switches, or other native user
interface elements or behaviors will be rejected.
5.1 Privacy
Technically, I'm not sure if it's even possible to change the WIFI not via the settings app, so I'd have a look their first. (https://apple.stackexchange.com/questions/1592/is-there-an-ipod-app-to-easily-switch-wifi-on-and-off)
I don't believe I've ever seen an app or a way to change SSID outside the Settings app. I explored a way to detect network changes, connects, disconnects, which work fine while the app is running. I was never able to influence how the user connected, just that a change happened. It also falls apart pretty quickly when the user backgrounds the app. Trying to keep a background task open long enough to poll the current connection fails pretty fast.
I wish Apple would provide some system level notification of Wifi connect events. This could be very useful to developers that want a little more control than Background App Refresh events.

Custom BLE Advertisement on iOS

I'm hoping to create a BLE advertisement on iOS where I can control the advertisement on a byte level.
One use case would be to mimic an iBeacon advertisement. What is the iBeacon Bluetooth Profile (I want to advertise while my app is in the background which is why I'm not using CoreLocation)
I do not see a way to do this with the Core Bluetooth API. Is this correct? Are there alternatives using private API's or jailbreaking?
As the others already pointed out, there is no API on iOS that allows you to do this.
You can advertise as an iBeacon, but only when your app is in the foreground. When in background, the advertisement is removed and therefore cannot be discovered anymore (except for other iOS devices which explicitly scan for that service UUID). Also see the documentation here: Core Bluetooth Background Processing
If you would share your use case and what you want to achieve, maybe there are other ways to realise it.
My experience with iOS is that if it is something is not exposed in the API, there is no way around, except jailbreaking. For Bluetooth low energy the API is at GAP/GATT level, and very little at the lower levels (if anything) is exposed. Advertising is a LL (link layer) feature.
To illustrate how restricted the access is: When scanning for BLE devices you will not have access to the advertiser's MAC address iOS. In Android you have it.
I do not see a way to do this with the Core Bluetooth API. Is this
correct?
Since you have to set Manufacture Specific Data in order to achieve this, if nothing has changed you will experience exactly the same issue that I did. Explained here:
The advertisement key 'Manufacturer Data' is not allowed in CoreBluetooth
It is not possible.

Can an iPhone application running in the background transfer data via USB interface?

There are 2 iPhone applications. One application running in the foreground and the other running in the background. Is there any way to get the background application to send data over USB without coming into foreground? Ideally we want to keep the foreground app in the foreground, while the background app process some data. Once the data is processed it will inform the foreground app that the data has been processed.
No it cannot. It cannot even do this without the use of private frameworks, unless you're in the Made for iPhone program. If you are, then your organization will know, based on the documentation made available to you, what you can and cannot access, when and how.
Should you be in the Made for iPhone program, and are unclear as to what you have access to and when, contact the person in your organization who is the technical contact with Apple for this program, they will be able to give you the details.
If the task is started while the app is in the foreground and you call the appropriate beginBackgroundTask/endBackgroundTask methods, you should be able to have it continue running after the app is backgrounded.
Note that access to USB is restricted (see jer's answer) and that there's no officially sanctioned way to communicate between different apps on the same device. Also, you can only buy/download one app at a time in the App Store and I can't see Apple approving an app that required you to download a second app for it to work. So you may have bigger problems to solve first.
It would help significantly if you told us what you actually wanted to achieve. For example, "I want MyApp on the user's phone to communicate with MyApp on the user's computer".
The absolute easiest way is to send data between the phone and a computer is to require that they're both on the same Wi-Fi network. Several iPhone apps incorporate a web server (this was the easiest way of "file sharing" before OS 3.2), and many more iPhone apps connect to a computer running server software.
Your other options, more or less:
Reverse-engineer the Bluetooth side of GameKit and reimplement it on the computer-side. I'm not aware of anyone who's done this. Loosely, I think it's IP over Bluetooth PAN plus some sort of Bluetooth service discovery.
Audio input/output, e.g. the headphone jack or certain pins on the dock connector. I'm not entirely sure how the mic side works (the resistance was a bit high for a carbon mic when I checked), but you might get lucky and find a way to turn it into "line in" or find "line in" pins on the dock connector.
A webcam pointing at the iDevice screen (and the iDevice camera pointing at the computer screen). Ewwwww.
Join the MFi program.

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