How does clicking a button on a wearable or moving a phone (client) near the wearable (server) automatically pair the phone and the wearable together?
For example, simply bringing a phone near the Nike Adapt BB shoes connect the phone and shoes together, simply opening the Apple Airpods case triggers a connection notification on the iPhone, and simply scanning the Apple watch face connects the Apple Watch and an iPhone.
My theory around this is that clicking "Pair" on an App triggers the app to run a BT scanning code file. At the same time, clicking a button on the wearable initiates the advertising sequence. And the two devices pair due to some commonality between them. I'd like to know what this commonality is. And what happens in the case that there is no button on the wearable to click? And lastly, how can I start making this system? I'd like to make an app that says "pair" and connects to some BT device (headphones, speakers, wearables, etc).
To give you more clarity, I am trying to connect an ESP32 (server) to my phone through an app (client) I create. I'd like to achieve a process where simply bringing the phone running the app, near the ESP32 pairs the two devices together or clicking a button on an ESP32 pairs the ESP32 to an app running on my phone.
Please let me know if you have any questions. Thank you in advance for helping me understand this.
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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.
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
I need some help because I don´t know how to approach this challenge.
I want to build a device, that's receiving a Bluetooth audio signal and is forwarding it to a Bluetooth speaker. It´s also running some algorithms with the audio data and also simultaneously sending results via UDP to a different device.
I already thought about using two or three ESP32s, using one with an extra Bluetooth module, or searching for a whole different MCU with Bluetooth 5.0 or higher and Wifi 5GHz. But I don´t know approach the best is, or maybe a completely different one.
Some context, why we want to do it:
We want to create a real-time light show, based on the current playing song. It is already working for PC, but also want to make it accessible for phone users. Sadly there is no way to capture the internal audio on iPhone or Android phones. Our Idea to make the music sync with the phone possible is that you are connected with the phone via Bluetooth to our "sync box" which is then connected to the speaker via Bluetooth or AUX. The "sync box" is running our algorithms for creating the light shows and then sending the data to the microcontrollers from the light strips.
So maybe you have an idea how we can sync the lights to the music completely differently or how I can approach the challenge with Bluetooth.
Any help is highly appreciated.
Thanks a lot.
I'm currently doing a test UWP app, the goal would be to put this on a Raspberry PI with Win 10 IOT ont it.
I've not much content, the application just display all the zodiac signs, and when one signed is clicked, it displays the current sign information. This will be display on a monitor here. So I would like to be able to navigate between sign, with a remote by example(but I'm open to any other proposal).
What would be the more adequate to navigate on the application(knowing that I don't need to enter anything, that it's not a touch screen but a simple monitor).
Thank you
You could use the GPIO port on the Raspberry Pi to connect the device with any of external controllers of your choice. Wired buttons would be pretty simple, and for a remote your could use an infrared receiver. The GPIO allows you to interact with pretty much anything electronic so the possibilities are pretty much endless.
For interacting with the GPIO port you need to add a reference to the "Windows IoT Extension SDK" to your universal windows app project.
The samples repository has code examples on how to interact with the GPIO port, and many of them are explained with tutorials.
I want to be able to pair Microsoft PixelSense hardware with multiple mobile devices via bluetooth and I want PixelSense to know which device is which. So if I place two phones on a table, PixelSense should be able to label them by device name. My initial thought was to have the phone display an Identity Tag that has encoded its Bluetooth MAC address so that it could associate them but PixelSense sees in infrared and can't read the phone screen so that idea is out. Can anyone think of another way to do this?
Microsoft has demonstrated a way to do this in their Mobile Connect sample application. They've ingeniously used the fact that almost all phones have a camera that faces down when the phone is placed on a flat surface. So they created an app that will read incoming color data from Surface while the phone is sitting on it.
So it goes like this:
The Surface app starts and makes the Surface computer itself visible on bluetooth (although you may have to do this manually in admin mode, can't remember)
you run the mobile app on your phone, click connect, and place it on the Surface at a designated spot
the Surface flashes a serious of colors into the phone's camera
the phone decodes those colors into a pin and scans through all the open bluetooth devices it can see until it finds one that is a desktop running the appropriate service and accepts the decoded pin.
Now the two are connected with no need for manual input and the Surface knows which physical device it's talking to because it knows which pin it displayed to each device.
*Note - They don't actually allow multiple simultaneous connections in this sample app, but I see no reason why it wouldn't work.
One issue with this approach (other than being pretty complicated to code), is the need for the app on the phone. One way to make it easier for people to get the app is to display a Microsoft Tag or qrcode on the Surface for people to scan (they're much more likely to have a scanning app already). I don't think there's any getting around the need to have something installed on the phone if you're using bluetooth anyway.