Using My Android as a USB Device - android

I've been able to find a few posts on StackOverflow about how to control USB devices using an Android phone -- which I understand is impossible (The Android being a USB device and all.)
However, I would be perfectly happy to set up my application to communicate with the other computer (a Linux host) as a USB device. (Like a really expensive mouse...)
Does anybody have information about how to set up an Android app/phone to use the USB connection and exchange data with a host computer. Obviously, it already works at some level -- it's how Eclipse and Android SDK/debugger do what they do, but I'm still looking for some way to do this in an application.
(My current phone, BTW, is a Droid Incredible.)
Thanks,
R.

Basically you'd need to install the USB device driver and the ADB toolsuite from the SDK, either that or reverse engineer their functionality and build it into something else.
Then you enable USB debugging on the phone.
And then you can do something like an adb port forward to allow an application on the pc to connect to a network socket listener on the phone. Note that connections cannot be made in the other direction, but once a connection is made it is bidirectional.
If your version of android supports tethering over USB, you could also leverage that to implicitly create a network between the PC and the phone, at which point you can make connections in either direction. Just make sure nothing starts accidentally pumping lots of data through the phone's mobile network!
(Many android phones actually can experimentally function as USB hosts, but you have to compile new drivers into the kernel, install the new version, and make up a cable to provide USB power to the device as the phone cannot. Also you lose the ADB over USB channel which makes debugging a pain)

Related

How to debug application on real device by using WIFI while not being able to use cable at all

My MacBook computer battery is broken and somehow it has not enough power to power device by usb-c adapter so I cannot connect anything and only have to use android emulator. But I need to debug on real device while testing some ocr sdk that obviously don't want to recognize anything in android emulator virtual scene. I asked other question about that but still I am puzzled by this inability to use WIFI for usb debugging because sdk runs fine on my phone but to debug using fabric and APK deployment is really horrible dev experience and productivity.
Is there some way I can setup WIFI debugging without cable at all... Maybe I need to root my device but again how to do it without cable, it seems impossible either way. I feel in like in dead and but still asking question here. I have computer and phone but cannot connect them for debugging by wifi.
Afraid I don't have an easy wireless solution. The closest thing I could find is that android wearables may have a debug over bluetooth feature, but it's built to route through another (wired) android device.
There is likely a feasible wired solution though- you can hook the device to a powered hub and the hub to the computer.
You could also use an adapter of sorts. They were built for printers and such before everything came with wifi and could get a proper wireless setup going without either side realizing they aren't directly connected over USB (OS still knows that some funky usb drivers are loaded and a separate application may need to run to connect), but again more hardware. A decent Wireless "USB Device Server" seems to run ~$100 while wired ones are cheaper, but not as cheap as a powered usb hub.
If you have another machine, you can use it to enable wireless debugging on your Android phone. See https://developer.android.com/studio/command-line/adb#wireless. Once wireless debugging is enabled, you can connect to it from your Mac without using USB. You still need USB for enabling wireless debugging though, but you can do it from a different machine. This should work on all Android phones, root is not required.
Update [2021]:
Things have developed since this question was asked. WiFi Debugging is a first class option now on newer devices. See https://developer.android.com/studio/run/device.html#wireless for details.

Broken Windows-Android USB-Connection between Device and PC

I've done a lot of research about rooting a device but I can not even come up to this point because my phone is not recognized by windows 8.1 at all.
My intention is to establish a usb-connection between an android-device(Samsung GT-I9506) and a pc in order to use it for phonegap. Some other devices properly work collaboratively with phonegap but this one seems to refuse all attempts.
Important points:
1. The device is charged up when connected to a pc.
2. Use-Debugging is enabled
3. All drivers are installed, furthermore it's a Samsung PC and Phone
A related topic is this one: USB connection issues
But unlike the problem in the topic above my phone does not appear in the adb-list when entering:
adb devices
I plugged my phone into another pc(Windows 8.1) as well where it was not recognized either.
Thanks in advance.
If your system installed Android ADB Interface Driver then only you can see your Device in IDE.
You can check that
Go to Control Panel
Go to Device Manager
And find Android Phone like
It turned out that the usb cable was the reason for broken communication between pc and phone.
Strange enough that this faulty cable was able to load the phone but unable to establish a communication channel to other devices.
And the moral of this story is a usb cable of a smarthphone might be faulty even if other electrial supplies are still intact.

Access Modem - Android Device (Nexus 5)

Device : Google Nexus 5 (Un-rooted)
Host Machine : Window 7
I want to Access Android Device as a Modem (using COM or Modem Port) and eventually pass AT Commands using HyperTerminal/Teraterm.
So after connecting the device to a Windows Box, The Device gets detected under Device Manager, but doesn't show any COM Port (other than the default COM0).
On right click and update driver, It shows it cannot find drivers.
I have tried the following options, but no luck with any.
Tried this on a rooted Nexus 5, but doesn't expose which /dev/smdX to use. Tried all combinations, didn't work.
Tried the Google USB Drivers from the Google Android's Website. No changes.
From here. I Installed drivers from LG Electronics, No changes in COM Port.
Universal Naked Driver helped me get to ADB Shell interface, but
thats not what I want.
In all of the Above procedure USB Debugging was enabled (Just saying).
I also heard the phone has to put into Modem mode to fire AT Commands.
If so, How do I do that ?
Or Is this a device driver Issue ?
Conclusion:
I want to access the Modem of the Android Device and fire AT Commands to it.
Could you please tell what am I missing ?
Any help on this would be really appreciated.
It's difficult to give an exact answer to this question, because it depends on how the manufacturer has implemented the device drivers. Unfortunately, there is a lot of information that isn't in the public domain.
It is possible, that the manufacturer has implemented some code to convert the device to a modem. Doing this yourself is device-specific, and proprietary. You might be able to get hold of a converter, for example bundled with the manufacturer's dashboard application for the PC, if such a thing exists.
Some devices don't expose the modem port at all. They may be visible as a network adapter, or as an always-connected LAN connection. If the device is visible as a network adapter, then you can access it via Windows Mobile Broadband API, or via MBIM for some newer devices.
To check if the device is visible as a network adapter, and get information about it, open a cmd box and type
netsh mbn show interfaces
Windows Mobile Broadband API doesn't give as many details as a good AT command set, but performs basically the same functions. MBIM is an industry standard interface with similar functionality, available on the Windows 8+ desktop via the Mobile Broadband DeviceServices API, for devices that support it.
If the device shows as an always-on LAN connection, there is probably a proprietary, high level interface for mobile functionality.
Driver behaviour can differ for different operating systems. If you have the chance to try the device on Windows Vista, 7 and 8, you may see different behaviour.

Programming Usb Connection with Android

I've started a project on Andorid, but I don't know NDK very much. I want to send custom data as per receiving message on usb port. I saw some applications that can send/recieve custom data on usb port if the phone is in recovery. I've programmed usb connection in windows before. But I haven't any clue where should I start in android. Is there any documentation for usb programming for android? If NDK isn't suitable to implement this, which options do I have? It is not important if the application is device specific.
The issues are more of system architecture and permission, an area where the NDK offers little in excess of the SDK.
Android does not really support (direct) custom use of the USB port, at least when the device is connected to a computer (there are some recent options when the device is hosting a USB peripheral). What is possible in recovery mode is essentially irrelevant, unless you want to make substantial modifications to the installation of Android running on your device.
Generally, the only practical way to do application-level communication between the device and a hosting PC is to use the IP networking paradigm over the USB cable. You do this either by enabling USB debugging on the device and installing much of the android SDK on the PC, or by enabling some forms of tethering which may create a general network as a side effect.
For the SDK method, read up on adb port forwards, including the limitation that the PC side must initiate the connection.
It may also be possible to create custom drivers which get a PC to pretend to be an android accessory kit (ADK) circuit and use the apis related to that.
Unfortunately, pretty much all of these ideas are more suitable for developers/power users, than for general consumer application. For consumer apps, most developers ignore the USB cable and do IP networking over WIFI, requiring the user to put the device and the PC on the same network, or proxy through an Internet server visible to both the PC and the device's mobile network.

USB Android I/O

Is it possible to access the USB port on Android phones? (Droid X for example)
Here is my usage case:
Have a USB device attached to the Android phone. The phone listens for data on this USB device. (The USB device is connected to a USB->RS-232 converter that has I/O attached to it)
This would be slick if possible. Does anyone know if this is possible?
Would be slick, yup. Not possible though. There's a feature request for it: http://code.google.com/p/android/issues/detail?id=738
Actually it is possible on a lot of the phones if you are able to install a new kernel with a USB host driver and rig up a custom cabling scheme to provide usb bus power to the device as the phone won't. A few phones even shipped with this capability already live.
I don't know if the Droid X specifically ships with this already, can have it added (if you are able to flash kernels), could have it added but no one has written the host driver yet, or is missing the hardware capability.
You also would need to enable the appropriate usb serial converter device driver (identified by experimenting with the device on a desktop linux box), but that's probably already in the kernel sources and just needs to be selected in the config. You may also need to create a device file for the /dev/ttyUSB0 or whatever and give it permissions appropriate to the application that wants to access it. (This requires root, but if you can reflash the kernel, you can get root)
If you want to pursue this, search the android kernel google group for posts about USB host mode.
One serious downside to putting the USB into host mode is that you loose the adb interface into the phone, which makes working on your projects hard. You'll probably need to either build an adapter for the low voltage debug serial port if there is one (as on G1, mytouch, etc) so you can get a console shell (or just use that instead of USB to talk to your peripheral) or at a minimum set up an ssh and sftp server on the wifi.
Since you want serial anyway, another option people have used is to get a bluetooth-to-serial module from an outfit such as sparkfun.
A bluetooth to serial adapter might solv your problems.
You can find one at https://www.sparkfun.com/products/582. Boards from other companies are also available for example on ebay.

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