usb-otg

问题 I'd like to know in which mode a USB-OTG-supporting Android device is by default, - in the USB host mode or USB slave mode ? I guess, if the device is in slave mode, then there's no point of using API described on link below ? https://developer.android.com/guide/topics/connectivity/usb/host.html Is there a way to programmatically switch from host to slave mode and vice versa ? As you know, a USB OTG (On the go) device automatically switches to host or slave mode, depending on which end of an

问题 I want to ask that there are application available in which user can connect USB to Android via OTG cable device and play the media (specially videos) contained by it. i have made a Broadcast Receiver to detect the attached USB, i want to read the content also. I am using this code snippet. private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (UsbManager.ACTION_USB_DEVICE

问题 Android 6.0 Developer Preview (API level 23) can natively mounts external removable USB OTG storages out-of-the-box without any additional apps (for more info please see: https://www.androidpolice.com/2015/05/28/android-m-feature-spotlight-external-storage-can-be-adopted-as-true-internal-storage-or-accessed-normally-with-no-additional-apps/). When user connects USB OTG storage, it shows up in the system storage menu and it is accessible with the built-in file manager. User can access all

问题 I am using StorageVolume API to retrieve URI for both SDCard and USBStorage by following StorageManager storageManager = (StorageManager) getSystemService(STORAGE_SERVICE); for (StorageVolume storageVolume : storageManager.getStorageVolumes()) { if (!storageVolume.isPrimary()) { Intent accessIntent = storageVolume.createAccessIntent(null); startActivityForResult(accessIntent, 11); } } In onActivityResult I am able to retrieve the URI, saving it to the SharedPreferences and taking Persisting

问题 My application uses UsbManager to communicate with USB cameras. Some devices don't have USB support. These will return null for (UsbManager)context.getSystemService( Context.USB_SERVICE ) , or they will throw a NoSuchMethodError exception when enumerating devices. I can detect both and display a message properly. Unfortunately, some Androids that don't detect USB devices cause neither of these problems. They just return an empty list of USB devices. How can I properly detect that this system

问题 I wrote a simple firmware for arduino to replicate whatever incoming data it recieves on serial to the serial output. Something like this: int serialData = 0; void setup() { Serial.begin(9600); } void loop() { if (Serial.available() > 0) { serialData = Serial.read(); Serial.println(serialData); } } Now I wanted it connect to my Nexus 7 running on Android 4.3 using a microUSB->OTG cable + USB->microUSB cable. I installed a serial monitor app (https://play.google.com/store/apps/details?id=jp

问题 I have a device (an mp3 player) connected to the smartphone through the USB OTG cable. I am trying to find an SDK of some kind which provides some API for file deletion. Right now the only software that was able to work properly is OTG Disk Explorer Pro 3.02. I managed to redirect its debug messages into a file to be able to actually read it. Here is a log: 2019-02-01 11:43:14 :: ODE :: >==< Found device: 0781:74E8 Class 00:00 >==< 2019-02-01 11:43:14 :: ODE :: >==< Device under: /dev/bus/usb

问题 I am trying to get filenames(and also the filepath), from a Garmin device which acts as a usb mass storage. Connecting the device to the computer, the filepath is G:\Garmin. Connecting that to the android tablet using OTG and Explorer(i have check the app setting - the package name is : com.android.rk), the filepath is USB/Garmin. Using ES File Explorer, I have seen that the file path is mnt/usb_storage/Garmin. So in the code, as I am trying to parse the system.xml from the file path usb

问题 in my application I want to read a file from usb removable storage I have a.txt and i want to read it void read() { UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE); HashMap<String, UsbDevice> deviceList = manager.getDeviceList(); Iterator<UsbDevice> deviceIterator = deviceList.values().iterator(); StringBuffer sb = new StringBuffer(); while (deviceIterator.hasNext()) { UsbDevice device = deviceIterator.next(); String Model = device.getDeviceName(); try { File file =

问题 I've got a Variscite VAR-SOM-MX6 running a Linux 3.0.35 kernel, with two USB ports. The first port is an OTG port connected to an external mini-OTG jack. The second is an internal host port going to a hub chip, and then to some other devices. If I've got an OTG cable plugged into the first port, telling it to be a host, then everything works fine. If I have a regular cable, or no cable at all, plugged in, then the second host port doesn't enumerate properly. There doesn't have to be anything