I am new to ANdroid development (but have worked on linux)..We can tune TCP parameters(window size..etc) to get better performance on desktop's either windows or linux.
Was wondering can we do the same on andriod based smart phones? ...i was informed that only on root access devices we can do it...how about non-root access devices?
This for all TCP based connections initiated from android device and not specific to a socket.
I was solution something similar to what we do desktop/laptop's ....i.e configure the TCP parameters in the OS example increasing windo size. so that any further connections started/initiated from the box would use that as the default value...
Thx in advance
This sounds like you aren't working with an app, you want the whole system(2g/3g/4g/wifi etc.) to move faster, correct?
In that case you must be rooted and the solution to your question is to flash a custom kernel that supports those options in its network stack.
With a custom kernel you can easily set the TCP congestion algorithm to your preference.
There are Socket.setSendBufferSize() and Socket.setReceiveBufferSize(). I don't see any reason why root privileges should be required.
Related
I want to send and recevice data between .NET application and Android Device by using USB. However, due to the security concerns, I do not desire to use Android Debug Bridge (USB debugging).
Is there any possible way to send and receive data from Android Device to my .NET application on computer by using USB ?
Thanks in advance.
There are many ways to skin this particular cat, let me name two:
Simple message files via MTP. Pro: Easiest to implement and widest possible client support. Con: High latency. Good, if you have few requests with a bigish payload each.
USB networking via CDC-ECM. Pro: Allows easy extension to full networking. Con: Not so broad client suppoort. Good, if you have full control over the hardware.
The prevalent problem is, that the fragmentation of Android allows you to assume only a very low baseline.
I do recommend, that you revisit the encrypted network connection option: It should be quite trivial to create a minimal network consisting only of the Android device and a single partner - e.g. by pluging a WLAN access point directly into a secondary network interface of the workstation - and by being associated to a special WLAN you make sure, that the device at this point is not connected to a different WLAN or mobile network.
This will not only be easiest, but also give you the best starting point if you want to upgrade to a broader network later on.
I need to stream a set of numbers, 6 floats, from an android device to a PC, to which it is connected by a USB cable. All the solutions I have found proposes using a WiFi connection. However, I have found that the latency caused by this is not acceptable. As such I have decided that I am going to hire someone to integrate the components, thus enabling direct communication. Until then, however, I want to try a variety of devices to see what works and the quickest way to "Integrate" two devices is by allowing them to share a (US)Buss. However, this is the one field I have zero experience with.
Do you make a socket and treat the connection as a network connection or is there another fancier way to achieve what I want? I have seen some talk about making a device driver for this purpose and I do not feel like crashing my OS 500 times again. I find it hard to believe that the android devices do not have some kind of driver already made that I can exploit.
The android code is written in Java, but it could be changed depending on what people suggest. The main chunk of mys system lies on the PC and is written in C++.
I need the latency of the stream to be as low as possible since the entire system needs to be as real time as possible. The limit is 15 ms between data acquisition on the device and the rendering of the simulation on the PC.
TL/DR: I need to stream data from a program on an android device to a PC with as little latency as possible; i.e. one way communication. As long as I can stream bytes I can design protocols and translate the bytes on the receiving end. My global cap is 15 ms and I need to stream continually updated 6 floats. What is the best way to achieve this?
Thank you in advance for your help.
Raw USB is probably not the way to go. USB is a device-oriented specification and cannot be used in a general send-arbitrary-bytes-across-a-wire way.
If Wi-Fi really is too slow, you could try purchasing an Android-compatible USB-Ethernet adaptor and connecting the device to the computer via a wired network connection, which might reduce the latency. Android recognises many types of these adaptors and you communicate over the network connection in the same way as other networks.
We ended up using the ADB brigde and it seems to be stable and fast enough for our purposes. All we had to do was to open a socket and connect with TCP. For some reason it fails when we try to connect with UDP, but I assume this might be due to ignorence on our part.
Is it possible to simulate a USB or Bluetooth device connected to Android?
I would like to make an app which is able to simulate an HID device locally. What I mean by this is: the app should make Android believe that an USB/Bluetooth HID device is connected. This would allow my app to inject touch events globally, I hope. Is there anyway to simulate a (virtual) device? Note that I don't really care about the device, I just want to use the built-in support for HID input.
I know a lot of people already asked about touch event injections but this approach seems to be a little bit different. I do not want to use this for testing purpose, so InstrumentationTestCase and the like won't help.
Rooting the device might be an option, although I can also imagine to ask my endusers to install a specifically signed app manually (according to https://stackoverflow.com/a/16737083/2923406 and https://stackoverflow.com/a/22902808/2923406 this works, but it would be device specific).
I am aware of:
Simulate a mouse input on android - This guy seems to do it in his own app, although his questions wasn't answered ;)
http://www.pocketmagic.net/2013/01/programmatically-injecting-events-on-android-part-2/#.U58SqfldVHV - Needs Root. Did anyone succeeded in using this? Also, the solution seems very device-specific again.
Bluetooth + simulating mouse - That's not what I want. The phone itself should not be an HID device, but use the (virtually created) one itself. Same for this:
https://stackoverflow.com/a/8174973/2923406
Note that I do not want to turn my phone into an HID device of any kind.
Simulating is a broad term. When I created my Bluetooth app I "simulated" a Bluetooth connection in two ways.
Way 1: Use a serial port UART converter and hook it up to a Bluetooth module transmitter.
Then you can use a terminal program like CoolTerm, to send your data.
Like so. In this case I coded in a string to send on successful connection with the device however you can make a infinite loop for testing purposes effectively not requiring your phone to be turned into a HID device.
Way 2 (not easy): Use your computers bluetooth in a server/client relashionship model.
This is harder to do. What you can do is convert your pc/mac into a server and the Android phone into a client or vice-versa. For this you will need to write external code which will need to be compiled separately on a jvm(java virtual machine). The procedure to do this can be found here. If you are using a Linux machine you have to separately download the Bluez module. I have not tried this on any other operating sytem other than Ubuntu, and it was a pain to get functional.
Hopefully that helped.
Yes, it's quite easy using the AOA2 protocol check this & this links for details ( you'll need to switch your device to the Accessory mode )
This may be possible (or at least be easier) using the Robolectric library, which simulates a full Android device locally. Although it is intended primarily for testing, the fact that it simulates a whole device locally - including Bluetooth and USB - means adding to it may be an easier approach.
In other words, you may be able to modify the classes it uses to simulate these abilities locally (i.e. in the IDE itself without an emulator or device) in order to simulate them on the device itself. After all, it does provide full simulations of these functions. You could simply change these Bluetooth and USB simulating classes to load onto the device itself rather than onto the local Robolectric test "device."
This is just an idea though - I can't confirm this will work - it just might be a good place for you to start.
I am thinking to try writing an app that can use android phone to remote control the desktop.
Just want to make sure my concept is correct.
So for the android able to
communicate with the desktop, I will
need some kind of protocol like...
maybe Bluetooth? In my desktop, I
should have a service app that open
Bluetooth connection for my Android.
Is Bluetooth is a good connection
for writing remote control?
Is it possible to use the Bluetooth
receiver from mouse to do the same
thing?
If you want to start with remote desktop I really recommend to you to first do a Desktop pc version before starting with the Android version.
Like Teamviewer. I recommend to do it with WiFi (WLAN) internet. Bluetooth needs a distance of maximum 20 metres. But if you want to do it fast, Bluetooth (instead of WLAN) could be better to do a presentation in the same room.
If you want to access the screen by using your phone, you need to access the mouse on desktop pc (Using of Mouse's bluetooth is not really possible). I think that is very simple. You also need to drive the keyboard. The difficult thing here is to do it with correct keyboard settings and character transmission.
Keyboard Hook
Also one of the most important things is to get it quick: Use Port forwarding on your router and on client side. That is a very tricky thing, Teamviewer is one of the best applications I've seen. They do not need it but still are working quick and direct.
Also take a look to your streamed images. Best way is to use MPEG4. But could be very tricky.
I would do it in the future with my WP7 and a DotNet app. Perhaps we can work together.
Yes, it can be done using Bluetooth, but a better option would be to use WiFi because it has more range and higher bandwidth. You can use sockets to communicate between mobile and desktop. Java provides a class java.awt.Robot which you can use to simulate mouse and keyboard events.
robot.keyPress(KeyEvent.VK_N);
robot.mouseMove(x,y)
Robot class also let's you capture screen, so it is possible for you to replicate desktop screen on mobile just like teamviewer. The complete process of creating an android based remote control is detailed here
I'm trying to figure out how to transfer frames rendered on a computer to an android phone. Wifi and Bluetooth aren't fast enough for a smooth framerate, but the data transfer speed across the USB connector is more than enough (up to 480 megabytes/ second). Thing is, I can't figure out how to do it- there's nothing in the Android docs and I haven't found anything online. How can I access the USB connection?
You can't access the USB connection in any documented and supported fashion.
It's not possible at all? Are there any hacks that allow it?
It's not an app for publication, and I don't mind messing with my own phone.
Try turning debug mode on and using adb to connect to the device. You can manually push files to the phone (e.g. to the sdcard) which you can in turn periodically check in your app. You can also write files the other way around (from your app) and have your PC app check that file, again over ADB. That way you can establish simple protocols for communication.
I also need this right now, but a bit more difficult since I try to access the phone from an programmable integrated device with USB host chip inside. Which probably means reverse engineering ADB...
Either way, it's a pretty hacky solution but it should work over all phones as long as debug mode is turned on, which makes it feasible.