Showing posts with label samsung. Show all posts
Showing posts with label samsung. Show all posts


Three Android smartphone reviews

The three phones in this article:

  1. XCover (GT-S5690). Smallest but thickest. Can be used under water, even. Gingerbread 2.3.3, upgradable to 2.3.6.
  2. S II (GT-I9100) A tiny bit bigger but half the depth. Gingerbread, upgradeable to Ice Cream Sandwich 4.0.2.
  3. Note II (GT-N7105 aka t0lte/t0ltexx). Massive. Jelly Bean 4.1.2, upgradeable to 4.3 at some time in the future. Perhaps even Android 5, they say.

GT-S5690 XCover

This is the XCover 1 and not 2. I have used this phone for 2 years or so, and yes, this phone is solid as a rock. I haven't been able to even scratch it, and it's still good as new.

The XCover is a so called 'rough', or 'active' phone, seriously modified but crippled to work in most environments. Mine has updated from 2.3.3 to 2.3.6 and has a total of 316MB RAM available, but the system takes some of that. A single-core 1.2 Ghz undeclocked to 800 MHz processor and a low density screen. It  has a system storage area of 165 MB, which is what you get to play with.

It's not a bad phone, but the slowness and memory shortage becomes obvious after a few months use. Well, actually it *is* a bad phone, because sometimes it can take 5-30 seconds for it to actually pull up the dialler and make the actual call. Someone needs to make the dialler a prioritized app in case of emergency. Seriously, on a bad day I can spend 30 seconds getting an outgoing call. It's a good entry level phone, and was my first Android.

The 'rough' aspect was what sold me, as I was initially opposed to miniature-sized and crippled computers that broke their screens if you lost them, and also caused you acute permanent squinting eyes-syndrome after staring at those small displays that the first smoarthphones came with.

Coming from a Samsung Solid Extreme B2100 (an ancient feature-phone), this was what I would start with.
Much has changed. Samsung has, at the time of writing, just been ranked the most profitable business in the world, completely obliterating Microsoft and Apple projects. And their phones are solid, Gorilla-Glassed multi-core SoCs that just reeks of high-tech. And most importantly, Samsung devices are open in nature and as such, has the hearts and minds of the geek hordes out there, inevitably making Android rise faster than you can throw a chair out the window.

This phone is easily rooted but has no active development on any custom ROM's. Someone did actually make a custom kernel to unlock 1.2 GHz on the GT-S5690M variant. This phone is obsolete now and replaced with the XCover 2, which will not sell more than the XCover 1, because they improved nothing, except adding a second core. The problem with this phone is the _memory_, Samsung! I have read that when you root it, you can set up a symlink so you can move apps off the main memory to the SD card as well. (In addition to the already moveable apps).

After I got the 7105, I wiped & factory restored it, rooted it and now it\s a backup phone in my always-on backpack. This phone will perhaps be used for a wifi security cam, or integrated with my Arduino boards in some way. It does contain 3G networking and an AM/FM radio, something that 4G devices don't.

Facts: (more over at gsmarena)
  • Gingerbread 2.3.3, TouchWiz UI
  • Dimensions: 4.80 x 2.60 x 0.47 inches (122 x 66 x 12 mm), 136 grams. Corning Gorilla Glass.
  • 3.65 inch TN LCD, 320x480, 160dpi display. VGA video recording.
  • 3.5 mm stereo jack, USB 2.0 micro-USB connector, both covered up.
  • GPS, Flashlight, loudspeaker, FM radio (RDS), with headset as antenna
  • 316 MB RAM, 158 MB usable. Supports microSD, microSDHC up to 32 GB. Uses mini-SIM.
  • Marvell MG2 CPU @ 800Mhz, GC800 GPU,, PXA968 chipset.
  • 3.15 MP single camera. 2048×1536 pixels. Video: 640x480 (VGA) (30 fps)
  • Bluetooth, A2DP, EDR, WiFi (802.11 b/g/n), Wi-Fi hotspot
  • Networks: 2G + 3G: GSM 850 / 900 / 1800 / 1900 and HSDPA 900 / 2100
  • GPRS, Class 12 (4+1/3+2/2+3/1+4 slots), 32 - 48 kbps, EDGE
  • Accelerometer, proximity, compass, magnetic sensor
  • IP67 rated, Water (Water), Dust, Shock proof
  • Battery: 500 mAh Li-ion
  • Wall charger. (Not USB-adapter)
  • microUSB cable
  • 2 GB microSD card with SD adapter
  • I have used this phone in -35 C winter, +45 C summer, in rain and wind.
  • I have dropped this phone, thrown it in the wall and there's hardly a scratch in the paint.
  • Decent sounding speakers. (Doesn't crackle)
  • Way too little memory
  • Small screen

 GT-I9100 S II

Everybody knows the S2, a lethally good phone that are only taken off the market because it's been replaced by S3 and now S4. (which are both ridiculously overpowered and  completely overkill for a phone!). This is a lighter phone and is more rectangular then the S3. I have installed CyanogenMod 9 on this one, and it's just fucking awesome. As the S indicates , it's a flagship model and it's essentially Samsung's Destroyer Of iPhones and need no further introduction, but I just have to mention this phone because after I installed CM9, the battery life on this is just ridiculous. Given, I have actually manually disabled the GSM module, this is just insane. Actually, I think S II with CM9 becomes a free energy unit. It's doubleplus good! It has a dual core ARMv7 and 1GB app mem as well as  8 GB internal memory. Of all my phones, this is the one that brings up the camera the fastest.

Fun Surveillance Fact: When it comes to wether the GSM module is active when the phone is off or not, this is extremely obvious to me now: The 5690 died after a few days, and the S II was still on 97% power after it was in it's 2nd week. The proof is indeed in the pudding and so is the NSA. Myth confirmed. As you all know; when you are on your 3rd straight night and your Google Fu is strong; it is not easy to do dig those links up later, but somewhere on the web is the dialler code for disabling the GSM module. In some tyrant countries, both in the east and the west, this might be a crime, just so you might know. But then againt, there was a time after and before Snowden, Manning & Assange.

  • Gingerbread 2.3.4, TouchWiz UI, Upgradable to 4.0.4 and then 4.1
  • Dimensions: 66.1x8.5,116
  • Screen: 4.3 inches, 480 x 800
  • 3.5 mm stereo jack, USB 2.0 micro-USB connector
  • 1024 MB RAM, 8 GB internal storage. Up to 32GB SDHC card.
  • CPU: Exynos, dual-core 1.2 GHz Cortex-A9 (Orion), Mali-400MP GPU.
  • Camera: 8MP (3264x2448) and full 1080p video recording. Secondary camera @ 1.2MP.
  • Wi-Fi 802.11 a/b/g/n, dual-band, DLNA, Wi-Fi Direct, Wi-Fi hotspot, BT v3.0+HS, A-GPS support
  • GPRS: Class 12 (4+1/3+2/2+3/1+4 slots), 32 - 48 kbps, EDGE 2.0. HSDPA, 21 Mbps; HSUPA, 5.76 Mbps
  • No FM radio
  • Battery: 1650 mAh Li-ion

GT-N7105 Note II

This is essentially an S III blown up to half tablet size. This is a so-called 'phablet'. And it's also the first smartphone I've had that I can type on without going insane from hitting 2-4 buttons at the same time. The screen is a fabulous 5.5 inches and it's heavy! Think of this rather as a PDA that can make phone calls, rather than a smartphone. At 1280x720 (and full 1080p over USB) this actually usable as an emergency computer when travelling or just on the toilet. From this I can pretty comfortably use a Terminal Emulator or SSH into my shells or scribble down some ideas. I've installed some compilers, but I haven't gotten to actually develop _on_ the phone yet. The 7105 plugged right into the Eclipse IDE as the 5690 and the 9100 did. I have started development on some (yet not existing!) apps and the 7105 is excellent to develop on, because it has both multi- and single window display mode!

The memory arrangement is a bit different than usual; both the internal memory and application memory are merged. And then it has only 'device storage'. This means that you cannot move apps to SD card as usual. Such it has a comfortable 8 GB app memory in addition to the 8 GB microSD card. However, I suspect this can be fixed if you root it and set up a symlink, like has been done for the S5690.

It comes with stock 4.1.2, and has some nice Note-specific apps. It does of course come with a stylus pen. This will enable extra UI features, as you can use the phone from an inch's distance. The stylus has a (non-obvious) button that acts as if you actually pressed against the screen. It has a nice AMOLED display and works reasonably well outside in the sun. It has an 8 MP main camera and a 1.3 MP front side camera. Be aware that it needs a mirco-SIM card. You 'regular' SIM card will not fit.

Yeah, about the front side camera. It sees you. It stalks you. It knows. It will rotate the screen to match your face. It will adjust the intensity level of the screen depending on ambient light, if you wish.  It will tell you the time if you try to reach for it. I shit you not. You can also talk to this phone, it will even start beeping if you walk away from the stylus pen. Creepy stuff. But at least I have it enclosed in a book-cover. This is the precursor to the Trapperkeeper 9000!

The 7105 has a CM for it, but it's not stable, and only provides experimental and nightly builds. At this moment, several of the last 14 builds would not boot.

Specs: (more info here)
  • JellyBean 4.1.2. Will be upgradable to 4.3.
  • Dimensions: 151.1 x 80.5 x 9.4 mm
  • 720 x 1280 pixels, 5.5 inches
  • 3.5 mm stereo jack, USB 2.0 micro-USB connector
  • 2048 MB RAM, 8 GB internal storage. Up to 32 GB SDHC card.
  • CPU: Exynos, quad-core 1.6 GHz Cortex-A9 (Orion), Mali-400MP GPU.
  • Camera: 8MP (3264x2448) and full 1080p video recording. Secondary camera @ 2.0MP.
  • Wi-Fi 802.11 a/b/g/n, dual-band, DLNA, Wi-Fi Direct, Wi-Fi hotspot,  A-GPS support and GLONASS
  • BT v4.0 with A2DP, LE, EDR
  • GPRS: , EDGE 2.0. HSDPA, 21 Mbps; HSUPA, 5.76 Mbps; LTE, Cat3, 50 Mbps UL, 100 Mbps DL
  • No FM radio. Accelerometer, gyro, proximity, compass, barometer
  • Battery: 1650 mAh Li-ion


Rumors has it that the S3 and the Note 2 will skip 4.2.2 and jump straight to 4.3. That is a shame, because there are several bugs in the 4.1.2 interface, most annoying is the fact that apps deleted from folders on the home screens won't always clean up the slot it had in the folder and the space remains empty and no amount of tinkering will make it right again. There are some others I've noticed too, like the background picture mysteriously disappears sometimes, only to come back after going in to the app list and back. The good news is that our devices has been chosen as the only two to actually receive 4.3. Some say even 5.0. For all your questions about rooting, and modding and the tools of the trade, refer to f.

A friendly warning: Do not use so-called M2 memory with Samsung phones. It's for Ericsson phones. They will die after a certain time. My wife and I got our 8 GB cards on the same day and they stopped working on the same day after a year or so! They were not rescuable. So, if you card has the letters M2 anywhere on the card itself, it is an M2 card!


Update, July 25th 18:52

Here's some more useful links that you might want to visit after reading this.

GT-S5690 files:

GT-I9100 files for changing kernel, checking FLASH, rooting and installing CM9:

GT-N7105 threads:

Generally, our friendly superhero chainfire has developed root techniques for several Android models. Check this site out.


Android Mega ADK test and design work concept

Here's some stills from booting up the CM9 modded S2 with an DFrobot Android Mega ADK (2560)

Haven't tested it yet, just installed the driver so far.
It appears to work and blinks green on boot and reset.

Rooted Galaxy S2

DFrobot 2A dual motor controller

Cyanogen 9/4.0.4 S2 with a 2GB SDcard

Robot top plate mounted on Rover 5 on some stand+offs

The shape of things to come....


Setting up an Android development environment

Books to read

Apress, Beginning Android 4 (2012) - Comes with source code available here
Although it says it's for Android 4.0, the book uses 2.2 but also tells the reader how to adapt to frameworks you don't actually develop for. Very clear and informational, and had me writing code in just a few minutes.

Addison-Wesley, The Android Developers Cookbook (2011)
Has the same clear style as the above one, with simple XML snippets and the code to support just that. I don't like tech books that wants you to build a huge application, when all you needed was an explanation for how to use a certain GUI element on page 76.

Software to get

Decide if you want Eclipse SDK 3.8 or 4.2. The 4.x series will eventually be better, but 4.3 won't be out until June 2013. 4.2 has a new internal UI engine. Meanwhile, the 3.x series is more than sufficient and also very fast. I also  keep my OS on an SSD drive, and my development stuff on a RAID0 disk. That does help when you are dealing with large Java environments. 

Setting up the environment

Download Android SDK here. This is the toolkit needed to link Eclipse to you Android phone, or to start up an emulator. You can set most Androids up to push debug messages trough the USB. These messages will appear in the debug console in Eclipse. This is generally not needed during normal app development. If you look trough the log you will see hundreds of notices about battery state, memory and the likes.

From the SDK Manger, you can download the API's and tools you want to target for. Some of the API's for the more esoteric phones require that you have a login at their respective manufacturers development network. You can safely cancel the ones you cannot download.

In the AVD (Android Virtual Device) Manager, you set up virtual machines that emulate the platform you want to develop for.

You create the project in File->New->Other->Android Application Project.

Now, all you have to do is to make a Run-configuration for your Android project. 

If you got this far, you should pretty much be able to run a skeleton application on your own USB connected phone 

Hardware and specs

I use a Samsung Galaxy Xcover GTS5690 for development. That is pretty much an S2 stripped of a CPU core and has less memory and smaller screen (a 'medium' class screen in phone terms, 320x480 or 480x320 rotated). Some programs even identify it as an S2. This phone has 512MB RAM, single core Marvell ARMv7 @ 800Mhz and a Marvell GLES2.0 chip as well as some yet unknown hardware for video playback of some formats. I have a 8GB SDcard stuck in it as well. 

While not high end, a quick survey among friends suggest the 2.x series Androids will be around for a long time. Samsung is even still making BIOS updates to this phone as this were written, and a mid-end dev system could be a good exercise in resourse management. Many people out there has low-end older phones as well as mid-end ones.

Flexibility across devices

Android was written with the fact in mind that devices will be different, so it has built in flexibility to handle this. Some things can be done even better with minor effort from the developer, such as simply targeting for a higher level API will enable functionality for adapting to 4.x enhances features.

Targeting a 2.2 device would cover 93% of the market. It seems the 1.x series is pretty much obsolete. Also, the changes from the 2.x to the 3.x and 4.x series seems to be smaller compared to the leap that was from 1.x to 2.x. Not having developed on 1.x, I cannot say for sure, but telling from the literature, most of the features people were missing in 1.x got generously implemented in 2.x. 

Messing up is easy

It's really easy to mess up an Android project, so keep your CVS up and running.


Rooting and modding Samsung Galaxy S2

If you just have to mess with your phone all the time and try out every option and setting, you'll probably have heard about replacing stock software with custom kernels and flashing in mods. This could expand battery life, give you new features and make your phone faster.

It can also render your latest phone investment as useful as a brick. Yeah, brick. That's what they call it when either you or some software you tried to run makes your phone shut down for good and it will never boot up again. So be warned, even though I am about to tell you how to possibly avoid it.


And don't try to be clever, the phone will tell your technician that you installed a custom binary. This feature is called the 'ROM counter'.

  • First of all, some phones are known to have a bad FLASH chip, and this includes most versions of the Samsung Galaxy S2, from what I can read. 
  • Personally I have the GT-I9100 which came with GingerBread 2.3.5. 
  • If you, like me, have Samsung Kies installed (if not, do that NOW) and updated the firmware, you will discover that GingerBread 2.3.5 will be updated to Ice Cream Sandwich 4.0.4.

At this point, download the following:

  • Siyah kernel - Will give you a temporary rooted phone. Get the correct version, and put it on your SD card.  (you do need an SD card)
  • ClockWorkRecoveryMod (aka CWM)

There is a particular problem that seems to come with the stock ICS 4.0.4 when you install the 'clockworkrecovery' mod. Therefore, first of all you need to root your phone to be able to actually check your phone. (with Siyah)

You also want the Google Apps extras

  1. At this point, you have to boot up into recovery mode, and wipe the phone and the cache. 
  2. Then, load this binary into the phone. 
  3. When it reboots, it will show you a yellow triangle below the Galaxy logo at bootup, and if you go to Settings->About Phone you will see that the kernel has been replaced. 
  4. If you forget to wipe the cache as well, the phone will not boot. (It is not bricked, just repeat the process.)

Then download an app called eMMC checker from the Play Store. Move CM and Google Apps over to the SDcard.

  1. Download eMMC Brickbug Check from Play Store
  2. Run check. It will probably say 'Insane chip: Yes' and then you must check the memory, for which you need to have the phone already rooted.
  3. If the memory check passes, your phone's flash chip is functioning well enough to flash the ROM, but it will still kill it of you skip to the CWM step now!

Note: Just to be clear, both the memory needs to be OK and the Siyah kernel must be installed or else you will have a dead phone before this tutorial is over.

  1. Boot phone into Recovery Mode. (Home + Vol Up + Power.
  2. Hold until logo appears, release keys.
  3. You will be presented with the recovery menu. Some phones has alternate combinations.


  1. Wipe and factory reset
  2. Wipe cache
  3. Install CM from SDcard
  4. Install Apps from SDcard
  5. Reboot phone

Now, when you reboot, the phone will be a completely different beast. Modded or not, the S2 and S3 are  formidable devices, featuring multi-core CPU and GPU processing, as well as standardized USB connectors, an array of special-purpose sensor chips and last, but not least, a Linux-based operating system to glue it all together. With the right add-ons installed, your phone is essentially a powerful hand-held computer that can be used for a multitude of uses. While the comparison  is not fair, I would guess an S2 outperforms 5 year old laptops.

I think this was everything. Please comment if I missed something.

Anyway, here's the result: