I have a custom build of AOSP (based on kitkat 4.4). I am controlling an arduino board via Android's USB Host API. I also am running a kernel that supports the CDC-ACM module.
I want to be able to flash new hex files onto the board. I have seen ArduinoDroid do this in his app. I have been able to flash using avrdude and the /dev/ttyACM* file that is created using the CDC-ACM driver.
However, when I grant permission for my app to communicate with the arduino board, the /dev/ttyACM* file disappears. Which makes sense because I am now controlling it via Android's USB host api. I am looking for either a way to restore the /dev/ttyACM* file or allow avrdude to use the /dev/bus/usb/#/# file in order to flash a new hex file onto the board. It doesn't appear that there is a revokePermission method in the USBManager.
The /dev/ttyACM* device file does not appear even after closing the device. I am running the following code to close the device.
connection.releaseInterface(device.getInterface(1));
connection.close();
I guess my real question is that there a way to get the kernel driver back after releasing the USB connection.
Because I am using a custom build of AOSP, I do not have google play and I cannot install ArduinoDroid on the tablet. However, I can run my app as a system level app if needed.
Ultimately I solved this, but it does seem like a bit of a hack.
Before taking control of the device (on a reboot of the tablet), I checked to see if any /dev/ttyACM* files existed. If they did, I then checked the /sys/ file system to check to see they were the correct device. I essentially checked the vendor of the usb device and matched it against the known device. Once that was confirmed, I knew it was safe to try and upload a new hex file to the device.
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I am trying to develop a file communication system that interfaces between the respective file systems of a Windows PC and a connected Android device. I realize a better (or at least simpler) way to do this would probably involve using the adb push and pull commands, but I am gathering options/trying to avoid developing additional communications on the Windows side beyond its basic OS file access. I know it is possible to interact with the device's storage directly from Windows when the device is physically connected via USB - if I understand correctly, this is commonly done using MTP? However, I am also currently constrained to only being able to use an emulated Android device. The Android Emulator is a useful tool for a variety of development situations, but I am not sure it was ever intended to appear as an MTP device in Windows like its physical counterparts do.
So could anyone provide documentation or some other resource establishing either
an MTP, UMS, etc. Windows connection is indeed not possible with the default QEMU Android Emulator; or
it is, and how.
Judging by the answer provided here - https://stackoverflow.com/a/21633596/1399272 - it does not appear that accessing the Android file system using a mounted drive in the Windows file system is an option, regardless of whether it is emulated or physically connected. So my question becomes moot point.
I am looking for a solution which uses Android API to transfer a text file from an Android powered device to a computer through USB cable. I have found USB host but I cannot use this because the computer can not act as a device for the Android host.
Do you have any suggestions how I can achieve this?
I have solved this problem by using adb status-window to continuously check for device status, and when a new device is connected, the required files are transferred to the computer using adb pull command.
In order to achieve a portable solution (i.e. to run independently of Android platform), I just copied the files 'adb.exe' and 'AdbWinApi.dll' into my application and used the adb from there.
Had similar problem where a software installed in PC needed to be able to access file inside the android phone through USB. After long research here is what worked for me (not sure if this is the best solution but it worked). Windows has Windows Portable Device(WPD) API which can be used to enumerate contents of a device through USB (and copy files between client and device).
There are few implementations in java
http://code.google.com/p/jmtp/ (works well but doesnt support copy function from device to pc though there is some support available to do this with source code)
another one is jusbpmp (available in google repository)
(if somebody finds a well documented and maintained implementation do share)
but since jmtp didnt work for me (copy function source compilation(for 64bit OS) failed), wrote C# program from scratch to copy files from device to PC. here is a nice tutorial
https://github.com/geersch/WPD/blob/master/src/part-3/README.md
You can write an app which will use http to contact your pc and send (POST) data to a known endpoint.
Keep in mind that the app will only have access to the data belonging to the app. You will not be able to access an arbitrary file from the file system
I would like to turn my computer into an Android accessory using my application. So instead of a specialized hardware this will be just PC that will switch the phone into accessory mode, thus launching some Java app on the phone associated with the host hardware and create a communication channel.
I've found a sample code (plus some Java Android app) to do this on Linux using libusb. It works by "opening" the phone using the standard VID and PID. Then it sends a command to turn on the accessory mode, along with the metadata like model, version etc.
If the phone supports accessory mode it'll then disconnect and reenumerate with a different PID. The sample code then checks if it did and opens the new device.
However, I'm trying to get this running on Windows. I've found a few USB libraries, like LibUsbDotNet, but they all seem to require the device using a WinUSB/libusb driver. I've used a tool in LibUsbDotNet to generate a libusb driver for my phone, installing it over the old generic removable drive one. But this means I now can't access the phone as a removable drive when I want to, so this is not a solution.
Is there a way (preferably a library) that can open any connected USB device based on VID and PID, and then send a few raw commands to it?
After that the device will reenumerate with a different PID, which I can use to create my own WinUSB driver, so that is not an issue. I just need to inject some commands through/around the default driver to turn the accessory mode on.
(I would prefer .NET solution, but anything Windows is fine and I can write my own interop wrapper)
I am also searching for a similar solution. I tried the Linux version, with libusb, with little hickups, was able to communicate with the device.
While searching for the solutions on windows I tried many hacks.
If need to communicate with device in ADK mode, I need to send several Vendor Commands, now this I need to do while its connected in Mass Storage mode. This is impossible using Mass Storage driver. I tried to get the Node handle of connected USB device to see if could send vendor command, but there I could only file Get Descriptor requests. So I went ugly method, replaced mass storage driver with libusb-win32, to see it could do the same, YES, it worked, but not at all a good solution.
Still searching..
When an Android device is plugged in to a PC (through USB?), is the internal file system mapped to a drive letter on the PC? So that one can copy files to and from the Android under Windows?
And, can Emulator simulate the situation when it's plugged in? How?
Thank you in advance!
Yes, it CAN be mapped to a drive letter. It was much easier with something like a Droid X (Android 2.3), since it would show up as a mass storage device (disconnecting the card from your phone in the meantime), but it's also possible on newer phones such as the LG G3 if you're willing to install 2 free programs, which you probably would like to have anyway.
ES File Explorer - Remote Manager (FTP Server)
First, you need a file manager, not only because the built-in one is useless, but also because you need an FTP server. Install "ES File Explorer" on your Android Device. Then in the options, turn on the "Remote Manager" option, which will activate the FTP server and show you its local address like "192.168.1.3:3721. You can now access your phone as an FTP site from your computer when on your local WiFi network.
Net Drive - Remote Drive Mapping Utility
Next, all you have to do is install NetDrive: http://netdrive.net/ It's freeware and seems to be used by a lot of companies, because it lets you map cloud storage to local drives. That will allow you to map your FTP server on your phone as a local drive.
Don't bother trying to map an FTP site with explorer. First, you may run into a problem that's apparently caused by Chrome, where you can't even add an FTP network location. You'll get an unexpected error telling you the path format is invalid. Interestingly, that is solved by opening the registry editor, then under [HKEY_CLASSES_ROOT\ftp] add a key named "ShellFolder" with string value "{E436EBB6-524F-11CE-9F53-0020AF0BA770}". The error will immediately cease occurring, with no restart or any other action required. Just go back in and add the ftp network location. That, however, still does not allow you to map it to a drive letter, which is why you need NetDrive.
As of Android 4, the wise ones have removed USB Mass Storage support for accessing the internal phone memory. So you no-longer get direct block-access (or a driver letter in windows). You can usually choose on the phone between MTP, or PTP (Media / Photo Transfer protocols) for whichever your OS supports better.
If your device has removable storage it should still support USBMS (with a drive letter) for that partition. At least Android still supports that, but your Manufacturer or Carrier-ware may still fail you here.
However, when it comes to the phone memory, there was a trade-off made in Honeycomb. Unified storage prevents wasted space (no more separate storage for phone / data, and having one fill up first and having confused frustrated users trying to move apps to SD, etc). The trade-off requires that:
Android can no longer ever yield up the storage for the host PC to
molest directly over USB.
Initially for Mac and Linux where support for MTP/PTP has been slower, You can use an FTP app on your phone. But now there is an increasing number of Desktop (PC/Mac/Linux) apps that understand and support the MTP or PTP protocols. You just don't get block access and so you can't get a drive letter without some hackery / third party software.
There have been hacks over the years to make FTP or WebDav or some other protocol work behind a windows drive letter, and something like could still work work for these MTP/PTP protocols, but I have yet to see any such consumer usable software for windows.
If your Linux distro doesn't include MTP support, gMTP seems pretty popular.
You can mount the device via USB but (in Win7 at least) it doesn't appear to have its own drive letter; rather it's treated like a camera or another media device. It doesn't mount automatically; you generally need to "opt-in" in the notification area with something like "Turn on USB storage"
Don't know about emulators.
Using Eclipse you can push and pull files to the emulator using the DDMS perspective. Doing similar on a real device, iirc will require root access to the device, at least to get to the 'sensitive' areas.
The SDK tools will also provide a way of push and pull via the command line.
possible with https://github.com/billziss-gh/sshfs-win
difficult finding good sshservers for android, know that at least one works but doesn't autostart at wifi and have to manually restarted, which it was possible to "come home from work, drive is connected"
this server seams to work fine
https://play.google.com/store/apps/details?id=net.xnano.android.sshserver.tv&hl=en_US
Wanted to backup(incremental) android device using Areca backup utility which requires src and dest to have drive paths.
After trying various methods like adb-sync, Syncthing, webDAV, etc. Got it working with ftp sharing.
Download any ftp server app. I used "WiFi FTP Server" by Medha Apps on Playstore to create a ftp server something like this- ftp://username:*#xxx.xxx.xxx.xxx:yyyy where username can be set in app settings and xxx is i.p. with yyyy as port number.
Map ftp URL to drive path by using free app- "DirectNet Drive"
Use the drive as if it's in your own system, though it will be slow being wireless.
I would like to have an application sync itself with some files on a host computer.. Anyone know if this is possible? Eg: When you connect an Android phone to a computer i would like an application on the android system to read some allowed folders on the connected computer. Making it so the user doesn't have to sync files itself.
I ask possible, because i assume it isn't.. for security.
You won't be able to do it solely from the Android end, because Windows doesn't make the local drives available through the USB port like that (unless you have some custom driver on the Windows side).
Your Android device will probably show up to windows as a USB drive. If you have an SD card plugged in, you may see a second drive from the Windows side.
To do something like this, you'd probably need to have software running on the Windows side that did the syncing, and then copy the data from the /sdcard directory on the Android device to wherever you ultimately need it to be.