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.
Related
I am working on an Android application that uses Bluetooth to communicate with a nearby PC.
The app works greatly on my own device (Samsung Galaxy Note 3 - CM 12.1) but on of my beta-testers it does not.
Simply put the app allows people to write and receive SMS from their
PC (with my C# WPF app) via Bluetooth & their phone.
My beta-tester is using a Samsung Galaxy Note 4 stock ROM (Lollipop).
At first I thought when his screens turned off, Android would kill the MainActivity which holds on a few threads including the one maintaining the connection alive (with a inpustream.read() blocking method). Such behavior does not occur on my own device : I could keep the connection alive for a whole night without plugging my phone.
I was warned, though, that using services would avoid such problem because Android does not behave the same way from one device to another. So I updated my app and made my MainActivity use my MainService to spawn the relative threads. But it did not change a thing.
As my title suggests, the problem lies with his antivirus and more precisely : AVG.
I have no knowledge on how such antivirus work on Android and I don't even use one. By freezing AVG with Titanium Backup on his rooted Galaxy Note 4, my app stopepd crashing and is now working perfectly well as intended.
So I wonder, how come AVG deciced to kill my app when the device screen turned off?
How should my app behave so that this won't happen with any other users using AVG or any other antivirus ? What should I do so that my app does not look as a suspect ?
I don't know exactly what the AVG did to your app.But I think that AVG may don't let your app force to turn on the bluetooth or use the Bluetooth when Android device is sleep or send/receive SMS.The AVG is one kind of antivirus apps that most of them have lots of permission request limited or power saving strategy,especially on rooted Android devices or the first part app already in the Android ROMs.
Try to make clear that what's the real point AVG did to your app.And then try to solve your problems with gentle and smart.
For example：
1.If the AVG doesn't let you use BluetoothAdapter.enable() to force to turn on the Bluetooth, try to use Activity.startActivityForResult() to let users to choose whether turn on Bleutooth or not.
2.If the AVG doesn't let you use Bluetooth when the Android device is sleep.You can try to use WakeLock.acquire() to hold the Android device.
3.If the AVG doesn't let you use SMS sending or receiving.You can changed another communication protocol, SPP or BLE or something else.
Maybe you have heard Xiaomi.If you are an Android Developer in China,because Xiaomi is very popular in China,you must deal with the adaption with Xiaomi,and then you will find that Xiaomi is really fucking for Android Developers in China.
Xiaomi doesn't some really amazing things to the original Android.For example:
1.
AlertDialog..getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
you can't alert the TYPE_SYSTEM_ALERT dialog on some xiaomi ROMs that they tell you nothing.
2.Xiaomi has modified lots of original themes.
3.Xiaomi has changed the Android alarm timing mechanism while the device is sleep which is called Wake-Up-Alignment.This is really terrible for the apps that with the function of timing.
The above problems are that I met in Android development, some problems I can resolve it, some you don't have any chances to change it.
Remember that:The adaption with Android devices is that you must make your users know you app works on most of the popular Android Devices,the developers try to make the app run on most Android devices,but it maybe not work on some Android devivces with customized ROMs or with some special third part apps.That's it ,that's true, that's Android.
If the problem can't be solved,it's not a problem!
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.
I'm planning to deploy an app on my android smartphone which is supposed to be used by multiple other persons. Now of course I do not want them to do things with the device they are not supposed to do so I informed myself about several different ways to make it as safe as possible (Lock-down apps, Kiosk mode, Mobile-device-management, Code-tweaks and so on).
I found some solutions that look really promising but they all share the same problem that a user could just restart the device and boot it in safe-mode where those helpful apps won't be started. However, there is one exception: I've installed a MDM app called maas360 which somehow manages to apply the restrictions that I defined even in safe-mode, for example by blocking access to the menu settings. How is that even possible? The thing is just that this is not a free app and it offers a huge variety of functions - overall it seems to be a bit excessive for my goals.
So my general question would be: is it somehow possible to restrict access to the safe-mode somehow? Maybe like a password? From what I understand it is not even possible to set a system password for Android devices that you'd have to enter once it boots (except if you set up a password for unlocking the screen first which would then be the same one... very redundant).
Disabling physical switch of volume down (in case of samsung devices) will stop access to safe mode on device. I dont find any other way to do so.
I am currently working on a research project which involves people playing games on an Android device. I am hoping to be able to write an android app that records the accelerometer and touch events. I would like my users to be able to play games such as angry birds, whilst I record their touching data.
I understand that this type of data collection is possible from inside the app, but is it possible from outside the app? (perhaps via an app running in the background?)
If this is not possible, are there alternatives? (I believe I could theoretically go into the android OS source code and make this happen?)
I understand that this type of data collection is possible from inside the app, but is it possible from outside the app? (perhaps via an app running in the background?)
For touch events, no, for obvious privacy and security reasons. It used to be possible (research the term "tapjacking"), but current versions of Android finally blocked this behavior.
For accelerometer events, you can record those, because they are the same for all apps simultaneously. Bear in mind that your sampling rate may not exactly match that of the app being used.
I believe I could theoretically go into the android OS source code and make this happen?
Yes, though you would then need to turn that modified Android into a ROM mod and install it on devices.
Apps are not allowed to do this on a secured device (ie, consumer phone/tablet that has not been 'rooted').
However, depending on your needs it may be possible with the development tools connected to a computer. If you can do some moderately annoying setup before each controlled-circumstances trial, I believe you can do it on some stock devices by using the USB cable to switch ADB into wifi mode, then monitoring input events over a wireless ADB session. See
http://source.android.com/tech/input/getevent.html
That document seems to imply that 'su' is needed (which is odd as the official 'su' isn't usable by non-root users), however it works without on many stock devices.
You'd probably also want to be running logcat to figure out what application is in the foreground.
I haven't seen this capability with any android app, nor have I seen anyone ask it. Is there any way that the Bluetooth or something can be used within your app to see a list of all the other android devices around you? For example, if my friend is using my app and he is in the same room I can see his device on a list in my app, and he can see mine...
There would have to be something that ties to two devices together, for example being on the same Wifi. As it is there is nothing that broadcasts to other devices that you are there by default. Even Bluetooth requires you to turn on discovery mode, or discoverable mode, and even then it will only stay on for a few minutes. If you wish for two devices to tie together, I am almost sure you could use the Bluetooth, but you would have to go through the normal process of discovery, synchronization, and permissions.
I don't think you can use BT to see what OS any phones around you are using, and they would also have to be set to discoverable.
If you want to make an app, it's possible to construct one where people agree to be located, but that's a voluntary issue, and it would be based on GPS radios in the various phones. I'm working on an app right now that has this capability, but again, it's something people sign up for so they can be located specifically for this purpose.
I would explore using the Google Latitude API as a possible avenue of exploration, before you reinvent the wheel creating a similar service.