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.
Related
I want to transmit data from Arduino microcontroller to an Android device, over USB port.
I dont have an Arduino ADK board, cant communication take place without this board and just the microcontroller?? How should I go about with this communication?
Also, Android 3.1 and further devices have the host mode, how can I use an Android 2.3.4 accesory mode for communication??
Have you checked out the IOIO? It doesn't use your computer's USB port...but I still think it could be helpful: https://www.sparkfun.com/products/10748
I have a general and quick question and since you can never get a hold of a developer at Google, I thought I would post the question here...
Can anyone tell me, if we want to use our phones to connect via USB to a missile launcher made by dream cheeky As suggested on the USB or ADK section of the developer's website, would we still need and Arduino board or a board that Google presented at Google I/O 2011?
I guess I am asking, in short, can we directly hook our phones to another device via USB, and compile a program via eclipse or with the ADK to have it run? or will we still need a board in between the phone and the device we want to connect USB...
Thanks in advance,
Richard
In ADK, the Android device acts as a USB Device and the Android accessory acts as a USB Host. When an Android accessory is attached to the Android device, the Android devices switches to "accessory mode (as described in ADK)". If your Android device has USB host already, still it will switch to accessory mode and acts as USB Device instead of USB Host. Actually, the motivation behind ADK is to make each Android device to work with any Android accessory. Accessory mode eliminates the need for USB host, since only few devices has USB host feature (It is costly).
So, if you want to work with ADK, you need an development card with USB host.
you do not need an ADK board if the device that you are connecting to your Android device is acting as the USB Device and your Android device is acting as the USB Host. This is the case with the Dream Cheeky USB missile launcher. You can connect a missile launcher directly to the device and control it. USB Host is only supported on Android 3.1 devices and later.
I am looking for a way to communicate with a control-board (u can consider it a sensor device) using USB cable. My sensor device supports usb but I think android does not have a way for that.
Can that be possible through Bluetooth dongle?
Is there any Android device available which supports USB host.
USB host has been "hacked" into a lot of android phones, but it's not very user friendly and weird cabling is needed along with a power supply as the phone won't power a usb device.
Some of the "first generation" android tables apparently had USB host on some models.
I've seen pictures of a Xoom connected directly (via a short OTG cable) to a thumb drive that it appears to be powering and reading from, apparently it was unofficial software.
As for your other questions, yes, you can use bluetooth if you get a bluetooth modem for your embedded device. Or you can use wifi. Some of the phones have low voltage debug serial ports. Or you can build a modem / DTMF control interface to connect to the headphone jack...
I am working on this Android application that needs to communicate over USB. I have an Archos 101 Tablet (specifications here: http://www.archos.com/products/ta/archos_101it/specs.html?country=us&lang=en). It has a full USB host port. I can put a flash USB drive in the USB port and copy files to and from the flash drive onto internal storage.
I have this Arduino Fio board, with an XBee attached to it. I have an XBee Explorer Dongle with another XBee that I plan to hook into the Archos 101 tablet into the USB port.
As of right now, I can put the XBee Explorer Dongle into my computer and send/receive data to and from the Arduino Fio, no problems.
Is there a way for Android to talk over USB? I know there has to be drivers somewhere in the tablet allowing USB communication, but I cannot find a way to access them or use them.
I can see Android recognizing the XBee Explorer Dongle. I downloaded a terminal emulator, and I can type "dmesg" and see that it sees the dongle hooked up. But I cannot do anything with it.
I seem to need a FTDI driver for Android.
I would greatly appreciate any help in getting my tablet to communicate with the XBee Explorer Dongle.
If you have root and can hack your kernel, FTDI offers its D2XX driver for Android OS. Check its website, please.
If your Android device is 3.1+, you should be able to use Android USB host to talk with Arduino. However, I met some issues on this.
If you have ADK/UHS at hand, your Arduino can act as USB host and talk to Android USB device. Even in same hardware, if your Android OS is quite old like 1.5/1.6, you have to use ADB interface rather than ADK (Accessory Developer Kit) protocol.
If you have Bluetooth, you can write your own Bluetooth SPP in your app.
If you can handle WiFi, you can write app to communication with socket, or via latest WiFi direct mode in Android.
Communication is various. However, it depends your hardware.
There is a solution by Inopiaaardbei using Arduino and a USB host shield with an Android Debug Bridge running on Arduino.
Using this solution you can use serial communication between the Android phone and the Arduino board.
See my post and the link inside for more info.
You can use an android adk or the android ioio connected to an xbee module as I did in this article. I have published the code on my github and another guy is going to implement the gui currently.
USB is not easy to programm, and it would be much easier with ethernet or rs232. However, if you insist, then take a look at V-USB (SW USB), LUFA (HW USB) and Lufaduino (HW USB). If Android has USB CDC drivers already embedded then it could be the easiest path for you if you implement it in AVR too. Slow, cheap and software only AVR USB CDC implementation is here.
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.