Is Entropy Slowing Down Your Android Device?

January 4, 2013 by Mike Szczys 50 Comments

[Lambgx02] got tired of his Android device getting bogged down and decided to dig down to the cause of the issue. His investigation led him to believe that entropy is causing the slowdown. He believes that his workaround reduces 90% of the lag on the average Android device.

So how is it possible that entropy is causing the problem? It seems there is a bottleneck when an app requests a random number from the Linux kernel running at the lowest level of the device. Android is set up to use /dev/random for all random number requests, but [Lambgx02] says that location has a very shallow pool of numbers available. When they run out the kernel has to reload with a new seed and this is blocking the app that requested the data from continuing.

His solution was to write his own app that seeds /dev/random once every second using a number from /dev/urandom. He mentions that this might cause a security vulnerability as seeding the random data in this way is not quite as random. There may also be issues with battery life, so make sure to monitor performance if you give it a try.

[via Reddit]

How To Used An Android Device With A Shattered Screen

December 13, 2012 by Mike Szczys 31 Comments

This screen is not just cracked, it’s devastated. We can all agree that you’re not going to be carrying this around with you anymore, but it might still be useful in other endeavors. [Mr Westie] wanted to use it for the camera which is undamaged. The issue is how do you control an Android device with a broken screen?

He knew there are apps out there that let you control your device remotely. But these still depend on you being able to install and launch the program. He found he could get the image from the screen on his computer using a package called Screencast. It runs on your computer and doesn’t need to be installed on the phone, but it will require a rooted phone and the user must click to authorize root access. He got around that hangup by pushing keypress commands to the phone via ADB. The only problem left is if debugging mode is not enable.

Unlocking Verizon Galaxy Note II And Galaxy S3

December 12, 2012 by Mike Szczys 13 Comments

galaxy-note-II-verizon-unlock

[Adam Outler] and friends have been hard at work unlocking the bootloader of some Verizon Android devices. His most recent adventure involves unlocking the Verizon branded Samsung Galaxy Note II.

You can’t run Cyanogenmod on a device that has a locked bootloader. This is presumably why it took no time at all for the XDA forum users with Verizon phones to raise enough money to put one of these puppies in [Adam’s] hands. He walks through the process he used to find the exploit in the video after the break. We’re not experts on the process, but apparently the .pit file used when flashing Odin is the entry point for the exploit. A bit of code has been injected into it which provides an opening to flash a replacement bootloader.

We mentioned the Galaxy S3 in the title. Apparently that has been unlocked as well but with one big hang-up. An over-the-air update could possibly brick the S3. To avoid this issue with the Galaxy Note II the original bootloader is patched and reflashed as part of the exploit.

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Common Linux Tools On Android Without Root By Installing BusyBox

December 5, 2012 by Mike Szczys 26 Comments

[Adam Outler] shows us how to expand the Linux tools available on Android without rooting the device. He does this by installing BusyBox. The binary is copied to the device using the Android Developer Bridge. He then opens an ADB shell, adds execution permissions to the binary, and runs it. BusyBox calls itself the Swiss Army Knife of Embedded Linux. It provides a set of very common tools which you’ll find useful in your tinkering. The one that [Adam] shows off in his video is the vi editor, but the basics that make a shell work are all there like: ls, mkdir, grep, dmesg, mount… you get the point.

So what are you going to do with your unrooted device now that you have these commands at your disposal? That’s really for you to figure out. [Adam] continues his demonstration by installing a package that does require root access. It’s BotBrew Basil, which adds apt-get and a few more complex packages. He then uses vi to write a C++ Hello World program, then compiles it and runs it. So if you’re looking to do some development on your phone this is one way.

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ODROID-U2 Is Latest Barebones Board Begging To Be Used

December 3, 2012 by Mike Szczys 49 Comments

odroid-u2

Oh hey, another barebones dev board. Well, that’s what we said to ourselves when we first saw this picture, but the way this is presented is like crack for geeks. It starts with this tiny board, which has a footprint smaller than a credit card. But once you start looking at the add-ons you’ll want to watch out or you’ll cover yourself in drool.

The name of the game here is speed. It’s running a quad-core Cortex-A9 chip with a Mali-400 graphics accelerator. There is no on-board storage, but the microSD slot is meant to be used for OS and storage. A faster option is to use a NAND add-on board offered in 8, 16, and 64 gig capacities ($25-$79). There is a micro type-D HDMI connector and the device is powered by a cellphone charger. It ships with a big heat sink that acts as a case for the board.

After the break you can see it booting Android and immediately loading into XBMC. The menu looks mighty snappy, making us think this is a great alternative to using Raspberry Pi as a media center. But you’ll pay for the faster speed and ability to run Android. The rig they’re showing off, plus the add-ons, comes out to about $132. There are also questions to be answered as to which video formats are supported through hardware decoding.

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Android VOIP Phone And Raspberry Pi Mate For An Intriguing PBX Setup

November 26, 2012 by Mike Szczys 5 Comments

[Ward Mundy] has found something great by combining a GXP-2200 phone with Raspberry Pi to create a private branch exchange. So the idea behind a PBX setup is kind of like a company intranet. All of the phones in the system are assigned an extension number and have access to the internal system functions like voice mail, and sharing phone lines to the outside world. We’ve talked about using an RPi as a PBX before, but the high-tech phone he’s using this time around pulls everything together remarkably well.

The GXP-2200 is available for under $200. It runs Android and has a full color touch screen pictured above. It is marketed as a multimedia phone and indeed it brings Skype and Google Voice to the party. But it also offers six SIP lines. The hardware even seems to be planned for this type of use as the phone offers a second Ethernet port to which the RPi board can be connected. In this example [Ward] simply screws the RPi to the phone’s plastic stand and connects the two using a six-inch cable. From there the PBX can be configured with the phone’s browser. How’s that for slick?

Scripting To Automate Your Mindless Android Games

November 9, 2012 by Mike Szczys 28 Comments

There’s a silly little Android game making some noise on the Interwebs. It’s called Curiosity which is a 3D cube with something inside. The thing is, every single pixel on the cube must be clicked in order to get through a layer. There are of course multiple layers, and… well, you get the point. [Stephen] figures this is a perfect thing for a bit of scripting and set out to find a way to automatically play the Android game.

As you can see above he’s got a pretty good start. To use the script in its current form he finds a part of the cube that is mostly solid green. The Android device is plugged into a computer using the USB cable, and the Android Debug Bridge runs the script. It’s amazingly simple, as it uses the monkeyrunner package which comes with the SDK. The proof is there, and it’s just a matter of whether or not he wants to spend his time to fully automate the playing of the game. You can see a demo of the script embedded after the break.

[Stephen’s] not new to automating things that he doesn’t want to do himself. Here’s an example of his code beating the PlayThru CAPTCHA.

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