I need to write a program that will alow an Android device (running version 2.2) to send data (a simple String) to another device (also running version 2.2) via a USB connection. Are there any libraries to do that?
I believe those devices would have to support USB host mode in hardware. And then one of them would need to be out in storage media mode, then you'd use standard filesystem access functions. But the hardware side needs to be dealt with first. I would check out special USB host cables to see what can be done. Not all Android devices can be put into USB host mode.
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I am about to write an Android application that will communicate with a device through USB. The device has implemented WinUSB.sys.
Is there any ready made USB lib that I can use in order to avoid writing my own USB driver for Android?
I haven't got a hold of the actual device yet, so it might be that I will be able to communicate via the built in Android USB lib. If that is the case, I will let you know.
Can Android phone's USB host support the TM4C123G as a device ,TM4C123G has been loaded the program which is a example named as usb_dev_bulk provided by tiva.
Who can help me? and give me some ways to achive this.
Your Android device needs to support USB OTG (On The Go), you need an OTG host cable and then you need to write an app that conforms to the Android USB Host APIs at http://developer.android.com/guide/topics/connectivity/usb/host.html
I would suggest trying out the excellent example app by #devunwired at https://github.com/devunwired/accessory-samples Specifically, try out the UsbMonitor app which shows if a USB device is detected, along with its interfaces and endpoints.
I want to build a device with sensors (either with an Arduino or a homemade circuit with a microcontroller) and I want to send data from it to an Android device via an USB cable. What is the library required to connect devices via USB? Is there any documentation I could read for it? The problem is that whenever I search for this I only get results about the ADK and their board, not for other devices.
Are there things I should know beforehand? I'm not new to either field, but it's my first project with the two connected.
Thank you.
The first thing to check is if your Android device is equipped with USB host interface. In such case you can connect a regular USB device to your Android and use this API to communicate with the device.
However, typical Android device (virtually every mobile phone) is only equipped with USB device interface, for connecting to PC or another USB host. In such case you have to use the Android's USB Accessory support. The most important idea behind Android Open Accessory protocol is that it swaps (logically) USB device and USB host roles. It's the USB host that looks for the device with particular vendor/product ID, selects particular USB protocol interface, and then simply uses the in/out bulk endpoints found to communicate - pretty smart, isn't it?
To build Android Open Accessory compatible device you then need a CPU with USB host interface. If you want to use Arduino, this shield is probably a good starting point, given its firmware implements Android Open Accessory Protocol already. There are some example applications as well.
This works great on my Nexus7 which is connected over the OTG to Arduino Mega.
Android USB host serial driver library for CDC, FTDI, Arduino and other devices.
Hope it helps!
You have two solution
1: Your Arduino board act as a USB host and power the Android device.
With this solution you have to implement and USB Host stack on your Arduino board and must implement Android Open Accessory Protocol. Your Arduino board must power the Android device. Then you app must use the USB Accessory API to communicate with your board.
Avantage:
work with almost all Android Devices (no need for an USB Host port on Android device)
Disavantage:
The device board is more complicated (must provide power for both devices)
Firmware is more complicated (must implement USB Accessory mode)
2. your Arduino board act as a USB device and the Android device powers
you board.
With this solution your do not have to implement a specific USB protocol. Your board will act as a standard USB device. Since you act as a device you can power your board directly from the USB cable (the Android device will power itself and your baord). To communicate with your board you will use the USB host API of Android.
Avantage:
the device board is very simple
the firmware is simple and easier to debug (you can even test it with you PC)
Disavantage:
Works only with Android devices that have an USB Host port
On most device you will need a specific cable or adapter (ex :otg usb host cable)
I have experience with solution 2, and it works pretty well. All source code for the Android source is available from the link below. I have verified that it works with sensor devices from the company where I work on the following Android devices:
Samsung Galaxy S3
Acer Iconia tab a200
Asus Tranformer Pad TF300T
But it should work on most tablets and recent phones you can see this post if you want look at our experience.
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..
What would be the best way to access the USB as a serial port on an Android device (HTC Magic)?
I am thinking about an OBD-II interface. Can I do this on a standard phone or more likely will I need a modified firmware?
According to this post, Matt Porter presented a review of Android at the Embedded Linux Conference Europe. I mention this mostly because of the example used to describe the current state of Android.
"Just one more practical example: You cannot even plug a USB drive to an android system, since /dev/sd* is not an expected device name in their hardcoded hotplug management.
Executive summary: Android is a screwed, hard-coded, non-portable abomination."
I'm sure someone's working on it, but I'm afraid for now you're out of luck unless you're willing to go low-level and edit the OS.
PSFreedom (project to jailbrack Playstation 3) has list of controllers which support usb host mode which then translate to supported Android devices.
My own expirience is that usb host works on HTC Dream/G1 without problems.
For OBD-II I would suggest bluetooth ODB-II dongle which side-stepps problem with usb host adapter.
Depending on the USB chip in your particular phone, it may be possible to rebuild the kernel to support USB Host mode or USB On-The-Go (Host + Gadget modes) instead of the normal USB Gadget mode. I've found some people speculating that it could be possible on the HTC Dream. Assuming you could reconfigure the USB port in Host mode a USB to serial, ODB-II, or CAN should be doable.
From what I can tell Android is Linux of some sort, to have USB device which would apear as serial port, you should write a driver for that device. I don't know much about OBD-II interface but i am guesing they use some sort of USB driver for windows, same is for android, not mentioning the application to handle the driver.
I don't think the current Android devices can act as a USB host only as a USB device when attached to a host. So using the USB port as a serial port is not likely.
Get a hostmode kernel for your device and you can use python for android and the pyserial library to talk to the serial over USB. I did this with Huawei Ideos U8150 (here is the post) for a loopback test.