I would like to beable to automatically turn on discoverability on an android device without the user being prompted with a security dialog.
I'm developing two applications, one for an Android TV box, one for my smartphone. I want to be able to control the android TV box using my smartphone, however I want to do this without needing to turn on discoverability manually on the TV box as that would require a remote of some kind completely defeating the point of the application.
Is there another way to enable discoverability through API which I could use - preferably via a service.
thanks,
Nathan.
Wow, 4 years go.
As an answer to my younger self I would think that what you were trying to do is not possible as you said so yourself, it's a matter of security (You yourself reference a "sercuity dialog").
If an app could turn on Bluetooth whenever it wished and had full covert access to the entire Bluetooth hardware, then the app could potentially with malicious intent damage parts of the Android OS and delete or worse; distribute the User's personal information.
What you would be looking at instead is implementing the system that computer peripheral manufactures implement with wireless keyboard and mice, that is to extract the Bluetooth connectivity to a separate hardware layer (A usb dongle) and via USB implement a human interface device, thus in turn filtering the Bluetooth connection to allow only the sending of HID input information to the device.
To myself 4 years ago,
Nathan.
A bit late, but you need to do this with an intent, from the documentation on Android Bluetooth:
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
http://developer.android.com/guide/topics/connectivity/bluetooth.html#EnablingDiscoverability
Related
I have a Bluetooth LE Joystick with a couple of buttons. I want to connect it directly to the app without using the Bluetooth Settings, but by connecting to it via BluetoothLeScanner.
I already can connect to a Heart Rate Monitor and get periodic notifications of the HR-values.
I also have created a little temperature/light/humidity sensor with an ESP32 to which I can also connnect and display the sensor values in the app.
My understanding of this HID device may be erroneous. With the help of the App BLE Scanner I can connect to this gadget via BLE and see the offered services.
One of them is 0x1812 HUMAN INTERFACE DEVICE, which contains a couple of characteristics of type REPORT, among others which are described HID OVER GATT PROFILE SPECIFICATION (HOGP_SPEC)
How can I find out which button got pressed, what position the joystick has been moved to? I guess that this has to occur via notifications to which I have to subscribe to.
Is there any Android library avaliable to handle HID input devices? What I do NOT want to do is to use the Bluetooth settings and connect to the device and have it become detected as a HID device and replace the keyboard with some odd mapping. I don't want the OS to get involved at all, just like when I connect and use the HRM and the ESP32.
I couldn't find any information on this.
I can connect to the device with my app, enumerate the services and characteristics. But from there on, I have no clue how to work with HID. Ideally I'd get notifications like "Button A has been pressed" "Joystick got moved to x=32" where x would range from -127 to 127, for example.
Accessing the HID characteristics requires the BLUETOOTH_PRIVILEGED permission since Android 5.0. The only way for an app to obtain that permission is to be signed with the same certificates as system apps.
This is a security feature, to prevent an app from receiving HID events from your keyboard and stealing your passwords.
Quoting from https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/BLE_5F00_on_5F00_Android_5F00_v1.0.1.pdf
4.6 Protected services
Android does not allow to read or write data to the following characteristics (and their descriptors):
HID Service (since Android 5):
a. HID Information
b. Report Map
c. HID Control Point
d. Report
FIDO (https://fidoalliance.org/) (since Android 6)
a. U2F (0000FFFD-0000-1000-8000-00805F9B34FB)
Only applications with BLUETOOTH_PRIVILEGED, that is, applications signed
with the same certificate as the system, are able to read and write
data to those characteristics.
While working with the Blutooth low energy I need to mantain the Bluetooth adapter on.
Recently I've realized that it can be turned on in two different ways.
First way:
BluetoothAdapter.getDefaultAdapter().enable();
First time I tryed this function I thought this required root or some kind of privileges to work.
Actually I find out none of them is necessary and this function works fine on different devices.
(Samsung S4 Lollipop, Asus Zenpad 8" Marshmellow, Meizu M2 Note Lollipop)
Second way:
enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, ENABLE_BLUETOOTH_INTENT);
By using the intent you can ask the user to turn on the Bluetooth. This one works fine too but you have to listen for intent result. So this require more code and the user can decide to not turn on the bluetooth.
Do they works fine in every situation? Is there a "better" one? What is the real difference between them?
As per documentation:
Bluetooth should never be enabled without direct user consent. If you want to turn on Bluetooth in order to create a wireless connection, you should use the ACTION_REQUEST_ENABLE Intent, which will raise a dialog that requests user permission to turn on Bluetooth. The enable() method is provided only for applications that include a user interface for changing system settings, such as a "power manager" app.
So basically the reason to use Intent is just a good UX. I advise to use Intent because of that reason.
In order to use BLE in your Application for receiving and transmitting data among device we must require blutooth enabled.
Another point is that device suport BLE or not.
Bluetooth adapter required for doing bluetooth related stuff.
If blutooth is not enabled on device , then ask for user to enable it by using intent and listen for intent. So this more code required.
If user do not turn on bluetooth we can't do BLE related things.
So, require bluetooth adapter and bluetooth on device and enable method provides user interface for changing system settings.
I can set a variavle when the app initialises to thell me if the Device Bluetooth is enabled.
There doesn't seem to be a method to enable Bluetooth from within the app, so I'm showing a notifier "Enable Bluetooth in Device Settings", but I'd really like to be able to disable Bluetooth when the app closes (if it was originally disabled - hence the variable) to conserve battery life.
Can this be done?
Thanks
This does not appear possible using AppInventor at this time.
It does appear that you have the ability to directly turn on Bluetooth, however, using the Android Bluetooth intent and the AI2 Activity Starter component. See (http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html) for reference and (http://www.whatakuai.com/bluetooth-and-app-inventor/) for implementation.
Sadly there does not appear to be a public Intent you can use to disable the bluetooth radio using the ActivityStarter component.
use the application Bluetooth Auto Off
it dissable the bluetooth after there is no comunication for selected time
https://play.google.com/store/apps/details?id=com.mst.btautodisable
I was reading this
http://developer.android.com/guide/topics/wireless/bluetooth.html#QueryingPairedDevices
which is allot of help on how to pair,connect to a bluetooth device.
I have a situation where I have several BT devices that are in Non-Discover mode always. I know the MAC and the PIN of these devices. IS there a way in Android Dev to manually add devices to the PAIRED list so i can just use the connect as a client.
I understand this maual is written allot for V3. i think i will need to do this on 2.0 ; 2.1- has anybody done this before?
Basically these devices I want to connect to are power saving modules I used pre built BT modules to monitor daylight, another one humidity, etc.. every 3hrs or when interrupted and runs of a single battery for months. So turning off divcory on server saves immense power and prevents other people trying to connect and waste battery.
Not sure what you mean by "manually": Do you mean "manually" as in GUI/user interaction, or "manually" as "I do it in my own application code"?
Some suggestions though:
If you can make your BT devices discoverable at all, you could do it this way:
Make your BT device discoverable
Let Android search for and find the device and then initiate a connection
Android will ask for the PIN for pairing with the device; enter the PIN.
Once pairing was successful, Android stores the pairing information for future use, so that you can
Make your BT device invisible again.
From then on your app should be able to connect to the BT device at any time without further pairing operations.
If the said is not an option for you, maybe you want to go another way:
In current Android versions there are different API routines implemented which are neither documented nor exposed in the normal SDK. A hack kind of solution may be to use some of these "hidden" ("#hide"...) APIs, either via reflection or via modification of your SDK installation.
But be aware that this is always a hack and it may work on a specific device with a specific version of Android and is likely to break your app on another device and/or any other Android version.
Having said that, here comes some reference:
Example of how to access "hidden" bluetooth API.
Then, have a look at the source code for android.bluetooth.BluetoothDevice, e.g. here.
In there, public boolean createBond(){...} may do what you want.
Is it possible in the Android API to communicate directly to another android phone within close proximity? If so, which version of the API is it in? For example, if both phones had the same app, can they exchange messages in the background within close proximity?
The short answer is yes. Some apps, i.e. Bump, already do that. Usually android phones have both WiFi and Bluetooth capabilities. Given that you are talking about close proximity Bluetooth should be enough for you. Alternatively once one of them is configured as a WiFi hotspot, you can connect them via WiFi.