Is it possible to simulate a USB or Bluetooth device connected to Android?
I would like to make an app which is able to simulate an HID device locally. What I mean by this is: the app should make Android believe that an USB/Bluetooth HID device is connected. This would allow my app to inject touch events globally, I hope. Is there anyway to simulate a (virtual) device? Note that I don't really care about the device, I just want to use the built-in support for HID input.
I know a lot of people already asked about touch event injections but this approach seems to be a little bit different. I do not want to use this for testing purpose, so InstrumentationTestCase and the like won't help.
Rooting the device might be an option, although I can also imagine to ask my endusers to install a specifically signed app manually (according to https://stackoverflow.com/a/16737083/2923406 and https://stackoverflow.com/a/22902808/2923406 this works, but it would be device specific).
I am aware of:
Simulate a mouse input on android - This guy seems to do it in his own app, although his questions wasn't answered ;)
http://www.pocketmagic.net/2013/01/programmatically-injecting-events-on-android-part-2/#.U58SqfldVHV - Needs Root. Did anyone succeeded in using this? Also, the solution seems very device-specific again.
Bluetooth + simulating mouse - That's not what I want. The phone itself should not be an HID device, but use the (virtually created) one itself. Same for this:
https://stackoverflow.com/a/8174973/2923406
Note that I do not want to turn my phone into an HID device of any kind.
Simulating is a broad term. When I created my Bluetooth app I "simulated" a Bluetooth connection in two ways.
Way 1: Use a serial port UART converter and hook it up to a Bluetooth module transmitter.
Then you can use a terminal program like CoolTerm, to send your data.
Like so. In this case I coded in a string to send on successful connection with the device however you can make a infinite loop for testing purposes effectively not requiring your phone to be turned into a HID device.
Way 2 (not easy): Use your computers bluetooth in a server/client relashionship model.
This is harder to do. What you can do is convert your pc/mac into a server and the Android phone into a client or vice-versa. For this you will need to write external code which will need to be compiled separately on a jvm(java virtual machine). The procedure to do this can be found here. If you are using a Linux machine you have to separately download the Bluez module. I have not tried this on any other operating sytem other than Ubuntu, and it was a pain to get functional.
Hopefully that helped.
Yes, it's quite easy using the AOA2 protocol check this & this links for details ( you'll need to switch your device to the Accessory mode )
This may be possible (or at least be easier) using the Robolectric library, which simulates a full Android device locally. Although it is intended primarily for testing, the fact that it simulates a whole device locally - including Bluetooth and USB - means adding to it may be an easier approach.
In other words, you may be able to modify the classes it uses to simulate these abilities locally (i.e. in the IDE itself without an emulator or device) in order to simulate them on the device itself. After all, it does provide full simulations of these functions. You could simply change these Bluetooth and USB simulating classes to load onto the device itself rather than onto the local Robolectric test "device."
This is just an idea though - I can't confirm this will work - it just might be a good place for you to start.
Related
In what way could I control an android app from another app that could be on iOS or android?
My use case is I want to be able to control an android tablet that's part of a smart-home product. In this case I don't have direct access to the tablet's screen as it's encased inside the product. So I'd like to control the tablet via another android/ios app.
Specifically:
be able to connect the android tablet to wifi
could I host a server on the android tablet to be able to communicate with it once connected to the wifi?
For part 1 I was thinking I could do something along the lines of have the tablet be in AP mode and use the client app to connect to it, is it possible to update the tablet's wifi once that is done?
If you were writing both pieces of software you could, although I wouldn't recommend it- Android is not meant to be a server OS, the battery optimizations and unreliability of Services make it a poor choice. Plain old Linux would be better. But controlling a 3rd party app remotely? You may be able to make something work, kind of. Something like connecting via wifi debugging, rooting the device, and sending raw touch events via the /dev/ filesystem. But it will be fragile, prone to breaking, and really hard to do. You're better off looking into open source solutions, like OpenHab.
Every now and then, the radio of my android phone silently dies because of some network related issues.
On the Nexus 4, it shows the empty triangle as if there where no service available in this area. On other phones it does not even do that. It looks like signal is fine.
Anyway, after the radio died silently no phone call / text message / data is going through in any direction.
The only hint I get from the System is the android.net.conn.CONNECTIVITY_CHANGE broadcast fired when the signal dies and wifi is not connected.
The only thing, that fixes the problem is restarting the phone.
Finally my question:
Does anybody know how to restart the radio completely by code?
I mean, it is a separate image running on a separate CPU. There must be a way to reboot it without rebooting the phone.
Maybe there is something, I can path into the Android ROM. I'm running CM here and be happy to patch it (again).
I tried fixing it by launching a system app by pressing *#*#4636#*#* on the dailer and stopping the radio and starting it again. But it did not help at all.
I recently made an app that checks the radio every time the connection changes. It shows a simple notification that tells me, I should reboot my phone. [1]
Issues reproduced on:
LG Nexus 4
Samsung ACE 2
multiple Apple iPhone 4*
Issues not reproduced on:
Apple iPhone 5
All phones running in the Dialog.lk network.
[1] https://github.com/felixb/network-checker
On a rooted device, one can issue the pkill command for all processes running as the user radio. I tested this on a Oneplus 3. The system seems to immediately restart the service:
pkill -u radio
Yes it is possible, but it will be difficult to perform on device without a deep understanding of the modem communications code of which multiple versions exist and even that will be dependent on if the system will permit you to even perform the communications on device.
The only one I am aware of that you can fully manipulate on device at this time is Qualcomm's (Qualcomm is standard in the majority of devices, but Samsung has used VIA in some cases which is a whole different monster, and even still another chipset or two exist), but to even be able to perform what your asking with Qualcomm's chipset, the following must be true:
The device must be rooted.
The application must have root access.
The system ROM must have the ability to place the cellular radio into modem diagnostics mode.
The device must have the appropriate permissions to permit the access.
At this point most people would connect their computer to their device and manipulate the cellular radio using QPST, CDMAWare, or QXDM. Options available to those users include everything from manipulating cellular subscriber data to restarting the cellular modem.
But, this is where things get tricky, you need to be be able to access this from the device side, which depending on the device, the operating system, and the configuration of it...may very well not be possible.
Also your application must be able to communicate with the cellular radio using the special protocol that the applications above use to do their communications which will require you becoming intimately familiar with that specification. The whitepaper for the Qualcomm diagnostics protocol is floating around on the web if you look hard enough for it.
Also on the not so cool side, if your application has access to the radio...so does any other rooted application (or even non-rooted, if you don't set the device permissions correctly) thus enabling rouge applications the ability to change your radio's configuration data potentially even bricking your device (which I have seen people do using the applications named above).
So my answer is Yes, you can do it, although:
Depending on your device you may not be able to, you should be well prepared to study and develop the needed tools to perform what you are wanting to do
No quick-start guide exist to be followed
Remember that you do so in the knowledge that your device could potentially be bricked either by a mistake in your coding or by a rouge application.
Rebooting the radio, as you have done in the device menus, may not help your problem, you may still require a device reboot
My advice is to use a much easier method and include a timer with automatic reboot in your current application, it is much safer, won't brick your device, and you won't have to become a cellular engineer to figure out how to accomplish it.
Your timer could begin counting down when the radio dies, and provide you an option to stop the reboot if your doing something important, otherwise it would restart your device and all would be ready when you reached for it to make a call or check your email.
Hopefully I was able to help, even though I know this is not the answer that you wanted.
Side note, if you could hijack Android's system configuration menus from an outside application you could potentially manipulate the radio state using the same methods used in Android...but you already discovered that restarting the radio in this method does not help your situation. Plus Android is designed to prevent such manipulation to prevent malicious applications from overtaking the UI of other apps and the system.
I'm trying to make an app on an Android device that will control an application on an iPad or Android tablet. (I'm testing with an Samsung Galaxy S2 and an iPad 2).
The application is pretty simple for now. When one selects a colour on the Android mobile, that colour displays on the tablet device.
The question is, how to connect the two devices. Just now I've verified that I can pair the two devices using Bluetooth. Also, the Samsung has a "Kies" Wifi Direct feature (which I don't understand fully), that allows the iPad to connect to the Galaxy as a wifi hotspot.
The connections are there, but I don't know if either protocol can be used to actually get the apps to talk to each other to get the control I'm looking for.
Should I be using Bluetooth, Wifi, or something else?
And in whichever case, how?
My opinion is that you should not stick so much around the physical medium used for connectivity either is WiFi or Bluetooth. You should abstract this aspect, in both cases you will be using sockets (I'm speaking about Android), if it's Bluetooth you will be using Bluetooth Sockets, if it's WiFi: TCP sockets. You could have a intermediate layer that abstracts the type of connection and through a factory to use either Bluetooth or TCP.
Bluetooth - http://developer.android.com/guide/topics/wireless/bluetooth.html
For WiFi you should study if P2P would help.
You will need two applications:
- one on the tablet - the server which listens for commands from the client (change color, do this or this)
- second on the smartphone - the client which sends commands.
I've built a few apps that do exactly that between iPhone and iPad. But the principle is the same. I used Bonjour networking. It's just a fancy name for ZeroConfig networking between devices. It's written originally by Apple but it's open source so there should be Android support out there for it too. Really simple and easy to work with.
If you already have a working connection then you already have the first half of your answer, that said you should really consider implementing a solution that uses a variety of connection types, WIFI, Bluetooth, etc.. The question I think you are really asking is how to pass data and messages between the apps once you have the connection.
There are a lot of ways to accomplish this. You could implement your own lightweight message passing system. If you haven't done this before it is more complicated than it originally seems, especially as you would be required to implement the system for each OS you end up using.
Should I be using Bluetooth, Wifi, or something else?
It depends on what situations you want your program to work in.
Bluetooth can provide a direct connection between your devices. A potential issue with bluetooth is that it has a limited range. If you're devices need to be far away from each other, you may want to go with wifi. Otherwise, bluetooth could work great.
If both devices are connected to the internet, you can make them talk to each other through there. The advantage of this approach is that it doesn't matter how far apart your devices are as long as they're both online. A disadvantage is that you'll have to figure out how to find the tablet's ip address before you can talk to it. This is actually a HUGE disadvantage because it can be quite problematic if both of your devices are not on the same wifi. You could have the user type in the destination ip address, but you'll have problems getting it to work if the user is behind a router (which will almost always be the case). The point is, it gets hairy.
If both of your devices are on the same wifi, you can use ZeroConf AKA bonjour (like Dancreek said) to figure out what ip address you need to send info to. I've previously used a library called jmdns (easy to find with google) to implement zero configuration networking. It's good because the user doesn't have to worry about ip addresses... it's intuitive for the user.
And in whichever case, how?
Networking is a pretty big topic, so I can't expand on this question to much. Short answer is, it depends on what method you choose. Search for some tutorials and start by getting one of your devices to send something as simple as an int to the other.
I've very interested in a new project, but it requires the user be able to access the phone's display via a wireless trackpad and screen. I'm thinking bluetooth is the best way to go. I can find a few resources regarding the bluetooth classes, but I can't find any resources for mirroring the phone's display or manipulating the ui with a trackball using blue tooth.
Are these two things possible? Could someone give me some information or point me towards some resources?
So you want to remotely control your Android Device with a Trackpad using Bluetooth for the connection? Do you need this for the whole Android System or just for your App?
If just for your App, their should be a way of doing this since communication between two Bluetooth-Devices runs over Sockets (like Client-Server communication). See the Androids Bluetooth API. But I'm also not sure how you plan to make the Android Device understand the Bluetooth-Commands which the Trackpad is sending to it (if you can even get both of them to connect to each other).
If you need it for the whole System, I'm not sure if this is possible (without rooting the phone and maybe writing some drivers for it), as I don't know any way of emulating a touch/click on the screen (which is basically what you want).
Although I know that there are some experiments running to connect a Bluetooth-Keyboard with an Android Device. But their is nothing official yet and nothing to look into (like SourceCode) as far as I can tell.
But maybe I'm looking at this a lot too complicated...
I am thinking to try writing an app that can use android phone to remote control the desktop.
Just want to make sure my concept is correct.
So for the android able to
communicate with the desktop, I will
need some kind of protocol like...
maybe Bluetooth? In my desktop, I
should have a service app that open
Bluetooth connection for my Android.
Is Bluetooth is a good connection
for writing remote control?
Is it possible to use the Bluetooth
receiver from mouse to do the same
thing?
If you want to start with remote desktop I really recommend to you to first do a Desktop pc version before starting with the Android version.
Like Teamviewer. I recommend to do it with WiFi (WLAN) internet. Bluetooth needs a distance of maximum 20 metres. But if you want to do it fast, Bluetooth (instead of WLAN) could be better to do a presentation in the same room.
If you want to access the screen by using your phone, you need to access the mouse on desktop pc (Using of Mouse's bluetooth is not really possible). I think that is very simple. You also need to drive the keyboard. The difficult thing here is to do it with correct keyboard settings and character transmission.
Keyboard Hook
Also one of the most important things is to get it quick: Use Port forwarding on your router and on client side. That is a very tricky thing, Teamviewer is one of the best applications I've seen. They do not need it but still are working quick and direct.
Also take a look to your streamed images. Best way is to use MPEG4. But could be very tricky.
I would do it in the future with my WP7 and a DotNet app. Perhaps we can work together.
Yes, it can be done using Bluetooth, but a better option would be to use WiFi because it has more range and higher bandwidth. You can use sockets to communicate between mobile and desktop. Java provides a class java.awt.Robot which you can use to simulate mouse and keyboard events.
robot.keyPress(KeyEvent.VK_N);
robot.mouseMove(x,y)
Robot class also let's you capture screen, so it is possible for you to replicate desktop screen on mobile just like teamviewer. The complete process of creating an android based remote control is detailed here