App for multiple platforms ? - General Questions and Answers

Morning,
firstly what programming language are the following platforms using:
Iphone, windows phone and android?
if i was to design and program an app in one of these platforms, is it easy to convert my code so that it can run on all of the above platforms?

Hi,
Android uses a form of Java (so if you know some Java that makes it easier to pick up - which i've done myself). I believe iPhone uses objective C, which I know nothing about! And Windows Phone 7 uses C# (shame they don't all use the same hey?).
If you're looking to write for multiple languages though, it might be worth using a site like: http://phonegap.com/about/ (again, I know nothing about it, but have heard of it and like the concept!).

Related

Creating a WM Application - Where to start ?

I hope this is the right place to put this, if not, mods, feel free to remove and/or delete it. I've dabbled a bit with C before, but that's about the extent of my programming experience. I'd like to create a program that will parse the information from a website and display it... I don't imagine something like that would be hard to do, but I have no idea what tools I would even need to start writing a PPC application.
Kitco (a website that gives live quotes of precious metals) recently came out with an application for the iphone that neatly formats all this information:
http://www.kitco.com/images/banners/KitcoiPhone/iphone.html
I'd like to basically create a PPC version of this application.
Is this something that an individual with next to no experience could hope to achieve ? I'd have to create a GUI, initialize the internet, connect and retrieve a webpage and remove the relevent information before displaying it.
Any help would be greatly appreciated. I've always wanted to become more familiar with these sorts of things and figured this project would be a great way of learning it.
Thanks!
ThreadMoved
Next to no experience? I dont think so. You have to have a little under your belt first and the only way to achieve that is to start readin right here!
I'm also interested in the expert answers to this question.
My very non-expert understanding is as follows:
VS 2005 (microsoft visual studio) can create executables for WM devices using a SDK (low level) or .Net CF (medium level) interface. You want to use .Net CF (compact framework) because it is supposed to make things easier. I think you have to use C++ to use the SDK but you can use C++, C#, or Visual Basic and write to .NET CF.
VS 2005 is an IDE (integrated development environment). It contains features to edit, compile, and even test your program using simulator/debugger. I think there are some non-microsoft IDE's that can also generate Windows Mobile code -- there is a market for cross-platform environments (e.g. programmers write code using a special library instead of the windows SDK or .NET function and the same source code can be compiled to run on Blackberry, iPhone, S60, Windows Mobile, etc...)
Instead of writing to the phone hardware (or .NET abstraction) directly, you can write your application using Java. You would use some Java compatible IDE (like Eclipse, Jbuilder, or NetBeans) to create Java applets that you download to your phone. You'd have to install a Java VM (virtual machine) on your phone to run these applets. I think the downloadable games for phones are Java applets.
Disclaimer: I haven't worn my "programming cap" since 2001 and hopefully things have gotten simpler. In my previous life I designed operating systems for mainframe computers.

Advice on a new hobbyist phone?

Hello XDA-dev community
For the past couple of months i've been thinking about getting a Pocket PC for a new phone instead of a Symbian Nokia [ah my old 6630, may she rest in pieces...]. Anywho, I think i've decided on the HTC Touch Pro / Raphael. At ~AU$600 it's the highest I was trying not to pay (i'm not rich), however it seems to be a pretty powerful and full featured device.
I do have a few questions I hope some of the kind experts/veterans here might be able to answer for me though
1) I written a few things in Java and PHP and other even-more-basic languages, but am interested in learning a new language with hopes to create software for both Windows PC and Windows Mobile. What choices do we as end-users have here? .NET is an obvious one [I own a copy of Visual Studio 2008 Pro], but are there any other languages of note?
2) From the Raphael specs on the Wiki here, it lists it as an ARMv6 architecture-based processor. This comes from the ARM11 family, which is the successor (I think) to the XScale family (ARMv5TE). Are these ARMv6 processors backwards compatible with 'XScale accelerated' binary builds of software? I.E., a PPC application has two versions for download/purchase - a 'Generic ARM Release' and an 'XScale optimized release' - would the Raphael ARMv6-based device be compatible with these XScale-optimized binaries? Or do ARM do things differently and ARMv6 is not backwards compatible?
3) Has anybody ever heard any rumors or made any talks about porting Android to the Raphael? Just curious. I'd prefer a Windows Mobile device (not a Linux user) but I can see all this OpenSource stuff does have a future... EDIT: Nevermind, I found the page at http://wiki.xda-developers.com/index.php?pagename=RaphaelLinux
4) How does the device perform with 3D-heavy applications? Does it make use of any sort of acceleration (I assume no, not like the iPhone for example).
OK thats all... thanks a lot for your replies, if there's anything else you think is worth mentioning to a soon-to-be-first-time owner of a Windows Mobile device, please do say so Cheers.
In reply to 2) VS 2005 Pro onwards targets code at ARMv4I, basically generic ARM processors also capable of running the Thumb (16 bit) instruction set. Thumb represents a limited set of ARM 32 bit instructions coded as 16 bit instructions. It allows much smaller code sections, but with megabytes of memory available these days who cares? If you code in .NET none of this matters anyway, as the code is created as IL byte code, the .NET runtime sorts it out.
If you code in Embedded Visual C++ 3 or 4 the target chipset is ARMv4. When you use the IDE to create the code on a WinMo 5/6 machine it complains that the target machine cannot run the code. It's lying, what it really means is it does not recognize the processor class. As it is ARM 32bit code only it will work.
It is not worth targetting the code for a specific, (read non generic), ARM chipset. You are just making a rod for your own back when it won't work on something else.
Thanks for the reply stephj. There will indeed be a bit of research for me to do as to which language and/or IDE I decide to choose to train myself in then it seems. Specifically though...
stephj said:
It is not worth targetting the code for a specific, (read non generic), ARM chipset. You are just making a rod for your own back when it won't work on something else.
Click to expand...
Click to collapse
...what I was referring to is - I've seen some freeware PPC software, mainly emulators, that have two versions - a 'generic ARM' one and an 'XScale Compatible' alternative version. On the ARMv6 based phones, assuming the software was released back when XScale was the newest ARM family, would both work on the Raphael? If so, which would be faster?
Obviously though, for a developer, creating the most compatible/generic code to work on the widest range of devices is the main focus - later possibly implementing optimiziations or hacks that are specific to a certain platform - but I'm just wondering if these already built, older 'specifically optimized' builds are compatible with the succeeded chipsets.
P.S. Do you know where I could find some resources on choosing between Visual C++ or .NET? I.e. pros and cons of each?
Thanks a lot!
jonusc said:
Hello XDA-dev community
...
1) I written a few things in Java and PHP and other even-more-basic languages, but am interested in learning a new language with hopes to create software for both Windows PC and Windows Mobile. What choices do we as end-users have here? .NET is an obvious one [I own a copy of Visual Studio 2008 Pro], but are there any other languages of note?
...
Click to expand...
Click to collapse
Since you have VS2008Pro, C++/win32 if you want fast and lightweight applications
"P.S. Do you know where I could find some resources on choosing between Visual C++ or .NET? I.e. pros and cons of each?"
.net pros
easy to get something running fast even if one is a n00b
got a lot of components meaning less time to develop
can be programmed with c# and c++ and even eeeeewww basic
.net con
slow as in sloooooowww
require one to install the framework if the app
require a newer version then what ones phone came with and the framework is pretty big
and people don't seem to have success with installing it on sd cards
compact framework is also limited in features vs. .net on pc so apps don't just port always
limited in features unless one do unmanaged code
c++ pro
fast
require no extre stuff
small in size and again fast
have access to every feature in the phone
c++ con
one have to do everything and that mean msg loop
and a lot of leg work just to get a dialog with a button
steaper learning curve
more risks of mem leaking
harder to debug as stacktrace is not just there
like on .net
Very nice, thanks for the replies guys
So from what I can gather, a basic .NET application would be ideal for RAD (quick and dirty), particularly GUI-centric applications, but tend to be bulky; whereas C(++) is a more native / low-level language and is thus faster, but very hardcore as most functions need to be done from scratch.
I should have assumed it's pretty much the same as a Windows PC
What about C++ versus C#? And does VS2008 have a decent API/IDE set for mobile development i.e. does it have many libraries for C(++/#) already included or are more easily available?
Thanks again for the answers guys... it's obvious i'm keen to learn about it, but i'm a little worried that someone like me going from stuff like PHP and VB to C might be biting off more than I could chew....? Ah well if .NET is gonna cause problems down the line, then I guess I have no choice
Don't bother with the C++ version of .NET, the casts that you have to make, to get it to work makes the code very hard to read, and besides it only compiles to the IL level anyway, it's just not worth the effort.
So, under .NET use C#, or VB if you prefer, there is not much difference between them, but in my opinion, C# is a bit more elegant.
Under C++ you have the choices of WIN32, ATL (Active Template Library), or MFC (Microsoft Foundation Classes), programming models.
WIN32 is the simplist but the hardest to code, the other two add progressively more objects to make things easier, but you need to distribute the run time libraries with them. A simple WIN32 app can be distributed as a single .EXE if the DLLs it already uses are part of the CE/PPC operating system.
PS When it comes to running code compiled for a specific ARM class on your device, just give it a go. If the CPU hits an instruction it can't run, it will throw an exception and stop anyway.
stephj said:
Don't bother with the C++ version of .NET, the casts that you have to make, to get it to work makes the code very hard to read, and besides it only compiles to the IL level anyway, it's just not worth the effort.
Click to expand...
Click to collapse
Fair enough. So C++ in VS2008 is a bad idea
stephj said:
So, under .NET use C#, or VB if you prefer, there is not much difference between them, but in my opinion, C# is a bit more elegant.
Click to expand...
Click to collapse
I thought VB was dead? Wasn't VB6 the last one they made? Or is VB just what they call generic/common .NET Framework apps? Anyway, yeah i've read good things about C#, especially compared to .NET in general. EDIT: Oh, .NET is not the program language but VB is *facepalm* I get it, nevermind
stephj said:
Under C++ you have the choices of WIN32, ATL (Active Template Library), or MFC (Microsoft Foundation Classes), programming models.
WIN32 is the simplist but the hardest to code, the other two add progressively more objects to make things easier, but you need to distribute the run time libraries with them. A simple WIN32 app can be distributed as a single .EXE if the DLLs it already uses are part of the CE/PPC operating system.
Click to expand...
Click to collapse
Ah, same as a Windows PC. That makes sense.
Thanks for the answers I think I might take a look at C sharp.
C++ in VS2008 is fine, use the smart device WIN32 ,ATL, or MFC models take your pick.
Sorry my mistake, the C++ .NET version is not available for smart devices. Its the three models above only.
After additional research, I don't really want to be tied down with the proprietary C# system. So is VS2008 a decent IDE for WIN32 C++ development on Windows Mobile? Or are there better alternatives?
VS 2005/2008 Pro takes some beating. After you have installed about 3 CD's worth of MSDN libraries all the help is on tap. The IDE also looks at MSDN online if you have an internet connection to see if there are any forums on the same topic you are inquiring about.
The code is generated as ARMv4I and can be tested/debugged on the images provided by the WinMo 5 or 6 SDK. The emulators are that good you only put it on your phone when you have tested it to death on the emulator.
EVC 3 and 4 use a previous method where the emulators run a x86 version of the code. I still use EVC 4 for code that has to run on anything, Windows Mobile 2003 for example.
It's all pretty proprietory, when it comes down to it, but I guess we're stuck with it.

Upcoming developer: which platform to concentrate on?

Hi there,
it seems to me most people here develop for WinMo devices, but maybe you can help me out nonetheless.
Currently, I'm a web developer in PHP (+ usual stuff). I studied computer science, so I'm not a newbie when it comes to coding I learned a lot of C and (unfortunately only) basics in Java and C++. I never got my hands on C# or VB and stuff - the only experience in developing applications for Windows Mobile was a small Texas Hold'em Clock (basically a simple countdown and some additional stuff) I did a few months back. I pretty much google'd everything I needed and copy'n pasted the code into Visual Studio - not really developing, but those where my first steps
I consider getting started in development for mobile devices like BlackBerry, Windows Mobile devices, iPhone, Symbian and/or Android. The problem is: I don't know which one of these might turn out useful on when I might be applying for a job later (which is basically my whole point doing this, I don't want to do web development for the rest of my life). Any thoughts?
What type of job do you want to do? first find out what the sort of jobs you want to do require, many software houses use c# so you could develop for windows mobile, if they require java then try android. Iphone uses objective c which isn't used outside of the mac world so unless you want to work for a company which creates mac programs maybe you should try something else.
Then again if you just want to make some cool apps and actually make money from them I would say iphone is the easiest to get you product to market then android with wm coming last.
also if you learn java then you can quickly pick up c# and vice versa so I don't think it really matters either way.
there are of course many other options, if you happen to want a job that requires python you could get the excellent upcoming n900 from nokia
Cant offer advise on that, but what you can do is write a better app for Facebook, the MS one SUCKS compared to the iphones (eeek i said the dirty word............)
ms's also sucks compared to the x1 panel facebook which again is not as good as iphones :S

running application in C on mobile phone with Android

Hello !
SUMMARY: How to run pocketsphinx_continuous on mobile phone with Android, and how to do it with simulator of mobile phone with Android. PocketSphinx can be downloaded for free here, for both Linux and Windows: http://cmusphinx.sourceforge.net/html/download.php .
Click to expand...
Click to collapse
------------------------------------------------------------------------------------------------------------
SHORT EXPLANATION
I'd like to create application for mobile phone and server such that:
1. User runs application on mobile phone with Android, this application uses PocketSphinx. It is Automatic Speech Recognition software for devices like mobile phones, written in C. Somebody told me that "Pocketsphinx is used successfully on Symbian with minimal effort". (However I think Android may be better choice). My knowledge about Android is limited but I know something about CMU Sphinx. Can you help me, please, to run this PocketSphinx on Android? I also need to find simulator of mobile phone with Android. I have already found Wireless Toolkit and I tried to use this emulator, however I think it doesn't allow to run simulation of mobile phones with Android. (By the way I am limited in my project to mobile phone of the price up to about 160 euro; which Android version would be best for my application?).
2. This application communicates with the user. The users speaks digits and some other words (dictionary is about fifteen words, I can create language and acoustic models, as well as formal grammar in CMU Sphinx, with the use of SphinxTrain). The application recognizes those digits.
3. Based on this talk, mobile phone sends information about results of recognition to the server. I can do it in Java for CLDC/MIDP with httpconnection, POST method on the mobile phone side and with Tomcat on server. I think this httpconnection must be possible not only in Java ME, but also in Android C. But this is thing which will bother me later, now I'd like to run pocketsphinx_continuous on Android and try to modify it according to my needs.
Summing up, what I'd like to know is how to run demo pocketsphinx_continuous on mobile phone with Android, and how to do it with simulator of mobile phone with Android. (I've got Wireless Toolkit but I think it is not capable of running Android). PocketSphinx can be downloaded for free here, for both Linux and Windows: http://cmusphinx.sourceforge.net/html/download.php . There are two ways of installing it in Ubuntu. First is to unpack it (it is tar.gz), enter its directory and type "./configure", "make", "sudo make install". The other, different, is written in README file, i.e. run autogen.sh, "./configure", "make clean all", "make test", "make install". The result should be, among many other files, javadoc in doc directory.
------------------------------------------------------------------------------------------------------------
LONG EXPLANATION
What is required to give me some advices is written above. So if you don't want / don't have time to read the whole text, just above explanation is enough. But let me say about other possible approaches which I try to do. Those are worse than what I explained above, but I also tried them.
CMU Sphinx contains SphinxTrain to create acoustic model. It has got some different recognizers (also called decoders), those are PocketSphinx, Sphinx4 and some other. PocketSphinx is written in C and is for devices like mobile phones. Sphinx4 is Java application for PCs because it requires better hardware. There is good tutorial about using SphinxTrain with Sphinx4. It is here: http://www.speech.cs.cmu.edu/sphinx/tutorial.html . There is no similar tutorial for PocketSphinx. However with some knowledge about Android and C it is possible to run it on Android. The other approach than PocketSphinx, is using this Sphinx4. However it requires connection between mobile phone and server, sending audio data from cellular phone to server. It can be done with Skype, but there is still problem on server side with redirecting sound from Skype to Sphinx4. So you see there are two different approaches. One is to run speech recognition on mobile phone with PocketSphinx and Android. The other is speech recognition on server with Sphinx4. There are some ways to follow this second option. One is Skype on both server and mobile phone. (But there is problem with redirecting speech from Skype to Sphinx4). The other is too expensive Digium card. The third one is IVR, but I still look for good open-source IVR software. All of those three ways of second option involve Sphinx4. It was much easier to create application with Sphinx4. It is for PCs, not embedded devices, because it requires better device, extensive floating point math and some other things. But it has much better documentation than PocketSphinx. But I want to use PocketSphinx because I don't need to pay to anybody for access to mobile internet in order to send data through internet for application like Skype. The access to internet is required only for short time to send little text data with httpconnection, POST method. This is why I'd like you to help me, please, with running pocketsphinx_continuous on simulator of PocketSphinx on mobile phone with Android. (By the way, I see I've got installed S60 Developer Tools -> 3rd Edition FP1 SDK -> MIDP -> Emulator).
Summing up in a list, those are in CMU Sphinx:
I. SphinxTrain, which I can use to create files needed for speech recognition
II. decoders which use speech input and some files which I create with SphinxTrain, to follow speech recognition (input speech + files from SphinxTrain = are used by decoder)
II-1. PocketSphinx, written in C, for devices like mobile phones
II-2. Sphinx3, written in C, for PCs, actually the best developed
II-3. Sphinx4, written in Java, for PCs, with the best documentation
II-4. Some other, older versions
Those are possible approaches of solving my task:
I. Speech recognition on mobile phone with PocketSphinx. This is much better way than [II].
Problems: 1. running PocketSphinx on mobile phone with Android. 2. simulating mobile phone with Android on PC. I also thought that maybe I should consider Meamo, what do you think about it? Or use things different than CMU Sphinx, e.g. Simon, HTK, Julius. I looked at those other ASR engines and I think PocketSphinx may be best choice.
II. Speech recognition on server with Sphinx4. There are some different ways of establishing voice connection between mobile phone and server.
II-1. ordinary call from mobile phone to server; server has got Digium card. Disadvantage: Digium card is expensive.
II-2. to use Skype on both mobile phone and server. Problem: redirecting of sound from Skype to Sphinx4 and vice versa.
II-3. can you think about any other ways? I found that Asterisk may be useful.
Greetings !
Summing up, what I'd like to know is how to run demo pocketsphinx_continuous on mobile phone with Android
Click to expand...
Click to collapse
First step would be to setup a toolchain and compile the prog for android
or statically linked with uClibc.
Then push it onto your device and test if it works as expected.
You can also push it onto the android emulator that comes with the sdk.
Just my 2 cents...
Thank you very much!
Can you give me any links to tutorials which can be useful for me?
By the way I know how to create my own application in Sphinx4 and I know how to run demo in PocketSphinx, but I've got some difficulties with creating my own application for PocketSphinx. So if you can have a look at PocketSphinx http://cmusphinx.sourceforge.net/html/download.php and tell me which files I need to have to create new project for PocketSphinx, I would be greatful. I mean that for Sphinx4 the only what I need to do is to enter S:\tutorial\sphinx4-1.0beta3-src\src\apps\edu\cmu\sphinx\demo\helloworld and create my own ...\demo\my_application, and inside it analogically to what is here ...\demo\helloworld. In the case of PocketSphinx, to run the application, I need to enter S:\tutorial\pocketsphinx\doc and run pocketsphinx_continuous. So I check what I've got in this file and I cannot see what files and where I need to have in order to create new project. I uploaded directory doc with pocketsphinx_continuous here: http://www.speedyshare.com/files/19429494/doc.7z
Greetings and thanks once more !
Rough outline: You'll need the Android SDK and NDK, both of which are available from http://developer.android.com/. The NDK will allow you to compile C code. You'll need to wrap the C core in a Java layer to make it accessible to the rest of the Android system. The SDK also includes an emulator, which I believe you've asked for if I understand you right.
I haven't actually attempted this, so that's about all the help I can be, but there is sample code included with the NDK that should get you started.
Thanks for your answer !
I check the google and see that NDK is term of Android, because I knew only SDK abbreviation. I assume NDK is especially for porting (like porting PocketSphinx for Android). So am I right that with this NDK I don't need to change code of PocketSphinx? I think it would be too easy .
There also other question which I've got. It is not strictly connected with Symbian but there wouldn't be any need for porting if I won't solve this problem. I've got my application in Sphinx4. There are also examplary appications for Sphinx4 and PocketSphinx. I can run demos from PocketSphinx (as explained in first post), as well as demos from Sphinx4. I can change source code of demos from Sphinx4 to perform my task. I'd like to do similar thing with PocketSphinx, but even if it should be easy task, I cannot do it. In Sphinx4 it is much simpler because all source files are in one directory. In PocketSphinx it is done in somehow different way. (http://cmusphinx.sourceforge.net/html/download.php). Without ability to move my application from Sphinx4 there is no need for me to port this PocketSphinx to Symbian.
Greetings !
johnyjj2 said:
I assume NDK is especially for porting (like porting PocketSphinx for Android). So am I right that with this NDK I don't need to change code of PocketSphinx? I think it would be too easy .
Click to expand...
Click to collapse
NDK is used to write software for Android devices that are compiled natively to the platform -- for now, this usually means ARM. Java as you probably realize is a bytecode intermediate language that the java virtual machine converts to native calls at runtime. This means that Java is generally platform independent whereas your C code is not.
JNI as used with the NDK is the Java Native Interface (or something to that effect). It allows you to call code that has been compiled for a specific processor from Java. This means that you could put heavily optimized super fast calculations in a native library and call them from your Java app.
It could also mean, that you've more or less written your entire application in some native code, and then you have written a java shim that has enough code to initiate and start your native software. Beware, there be dragons here.
The fact that you CAN do this, doesn't mean you SHOULD. There are a lot of benefits to using the android platform and specifically using the android way of writing applications. Concepts like views, activities, intents, etc., greatly simplify how an Android device interacts with other Android devices and provides a consistent and powerful framework.
For something like SCUMMVM, it is a game (platform) that is very linear in design; you are either actively playing it, or it is on pause. How other applications are running while using SCUMMVM is inconsequential. It sounds like you have very different requirements.
Thanks for answer!
Isn't that link (http://cmusphinx.svn.sourceforge.net/viewvc/cmusphinx?view=rev&revision=9470) simply trying to copy engine library to Symbian, without effect? Only enginge won't help, there is also need to write from zero code which will use this library. So it looks like there is still long way to have it working. Do I understand it properly?
Greetings!

How to develop an App for multiple mobile-OSys?

Hey there folks,
after reading these forums for quite a while and having several smartphones during the last years, I reached the point where I want to start creating my own apps. I tried to google around a bit and found some interesting tutorials on how to start creating apps. I also found several SDKs for different operating systems. But exactly that is the point leading to my question.
Before starting to code: is it possible to choose a platform from where my app can be delivered to each winmo, iphone, blackberry or android?
Or is that just plain impossible? I mean, those are all touch based devices Should'nt be that much of a difference? Originally I wanted to start developing an iphone app, but that would leave out all the android users and so on. I don't want to rewirte everything from scratch for an android device after having finished the iphone variant. And that did not even consider the advent of windows 7.
So, is there any way of coding for all the operating systems, keeping the effort of switching between operating systems low?
greetings and thanks in advance for your help,
your unexperienced coder-in-spe,
joker
While all four of the devices mentioned all use ARM processors of various flavours to do the work, they are four completely different operating systems, each with their own IDE and programming models.
Even considering Windows Mobile, you have to decide whether you are programming for a SmartPhone/Classic or a Pocket PC/Professional device. In this case it is possible to write code that will run on both WM platforms, but you will have to make that decision at design time, before you even think of writing a single line of code. Your application will then have to act accordingly, depending on the machine on which it runs.
java apps for symbian often works ok on wm using a midlet manager
not sure about android and blackbarry but being java not too much code would be required to port it I suppose
mind you java on wm work pretty poorly
and iphone got rules that you can only make apps using objective-C/c/c++ and their SDK
which is only available if you own a mac computer
Thank you for your answers. Looks like starting to code is not that simple as expected. So I will try developing for iPhone only :/

Categories

Resources