| <Martani/> Blog

Saturday, October 8, 2011 View Comments

Rolling Back a Project to Windows Phone OS 7.0 After an Upgrade to 7.1 (Mango)

If you had a project that was developed before the Mango SDK was available, or a project that was created with the Windows Phone 7.0 as the target platform and wanted to upgrade to 7.1, then there is no way to roll back to 7.0 again, which means that your app will be available only for those who have Mango updated devices.

On creating a new Windows Phone project with the Mango 7.1 SDK tools installed, Visual Studio prompts you for the target platform:

If for any reason, you want to upgrade the app to take advantage of the 7.1 SDK (use background agents, live tiles' animations etc..), you go to Project -> Project properties and set the target to OS7.1:

Once the Windows Phone OS7.1 version is selected, Visual Studio shows the following warning stating that once upgraded, the application cannot roll back to Windows Phone OS 7.0 anymore :

Because the referenced projects are not upgraded with the app, there is actually a way to roll back anyways, even if Visual Studio warns it is not possible.

First in the WPAppManifest.xml you need to change the AppPlatformVersion back to "7.0". Then unload the project from Visual Studio and open your *.csproj with a text editor. Locate <TargetFrameworkProfile>WindowsPhone71</TargetFrameworkProfile> and change it to <TargetFrameworkProfile>WindowsPhone</TargetFrameworkProfile>.

Reload the project in Visual Studio, and voila, it's back to version 7.0.

Hope this helps.

Friday, September 23, 2011 View Comments

Bloginto 2.1 Now Available

Bloginto 2.1 is available for download from the Google Chrome Web Store, the 2.1 version is a patch to the 2.0 version after the (abrupt) changes of Bloginy Algeria.

Bloginto is a Chrome extension that brings Bloginy Algeria and Morocco feeds to the browser. With Bloginto you can:

Read the live feeds of Bloginy Algeria and Morocco
Keep track of the new feeds and get notified whenever newer news are available
Keep track of the read and unread feed entries
Vote for the feed entries directly from the browser with 1 mouse click
Tweet directly through the extension

Bloginto is an open source extension, you can grab the source code from here https://github.com/martani/BlogInto-Chrome, you can suggest amelioration and patches too.

Tuesday, July 26, 2011 View Comments

nanosleep(), usleep() and sleep() Precision Tests

Working on some Amazon EC2 benchmarks I run through few problems of having my processes to run with a high time precision where a more than 1ms shift between operations is not acceptable.

My program accumulates work time and sleep time, ideally, it would work for time t, sleeps for T - t microseconds and loop again. The problem is that in the sleep routine, a shift of few microseconds can be accumulated to become a shift of milliseconds after few loops.

After investigating the problem a little, I did some tests on how precise are the sleep functions in C, here is the code I used to test nanosleep(), usleep() and sleep().

Running these tests on my machine with Fedora 15 gives me these results :

As you can see, there is always an overhead of 100µs to 180µs, a call to printf inside the function will take about 70 µs more to execute. The call to the function itself (the nsleep function) takes at worst 1µs. With this accumulation of microseconds, a program would get to a state where it is late by some milliseconds after a dozen of iterations and calls to these sleep functions.

On the other side gettimeofday() behaves pretty well considering precision, the benchmark below (found here) gives the following results:

$ ./gettimeofday_benchmark

50000000 cycles in 2315879542 ns = 46.317591 ns/cycle

Which is satisfying for its precision.

A solution (that is not applicable in all cases) is to have a global program independent clock regarding to which the sleep period is adapted. For example instead of waiting T - t microseconds, one will use every second tick on the system as a landmark, and thus any microseconds lost in the last loop iteration are discarded in the next one since the wait time is not dependent on the time the loop has started.

Monday, June 27, 2011 View Comments

NYTimes Newsreader and LeParisien Journal for #WP7

I've developped lately two new Windows Phone apps which are newsreaders based on RSS for the New York Times newspaper and LeParisien.fr Journal.

The two apps come in two versions,a free version which is ad-powered and a paid version which is ad-free. Following is a brief description and download links for the two apps.

NY Times Newsreader :

Read the NY Times newspaper directly on your Windows Phone device.

The NYTimes Newsreader gives you access to all the major sections of the NY Times newspaper organized in categories for easy and fast navigation with full articles view using the NYTimes' RSS feature.

Features:
- Browse news by categories (7 categories and more than 40 sections)
- Front page news
- Articles thumbnails
- Share articles by email and SMS
- Favorite your articles to read them later
- Read full articles directly from NYTimes Newsreader

Categories:
- World
- Op-Extra (Opinion, Columnists, Editorials, Magazine ...)
- Technology
- Science
- Sports
- Arts
- Business

Download (FREE version)

LeParisien :
Suivez toute l'actualité française et internationale avec LeParisien.fr Journal sur votre Windows Phone

Accédez à l’intégralité des articles de leParisien.fr classés par rubrique (5 rubriques et plus de 30 catégories)

> Sauvegardez vos articles favoris pour une consultation ultérieure
> Partagez l’information avec vos amis via Email ou SMS

Accédez en un clic aux dernières news :
- L'info du Parisien
* Politique
* International
* Faits divers
* Economie
* Société
* Loisirs et spectacles
* Médias et people
* Automobile

Download (FREE version)

Sunday, May 8, 2011 View Comments

Beta SMS 2.0 Now Available On Windows Phone 7

Beta SMS 2.0 is now available on the Windows Phone 7 Market place with a lot of enhancements and new features.

Beta SMS lets you send very cheap and even free^ short text messages internationally by using your favorite web SMS or VoIP provider. It offers a very intuitive way to send SMS directly from your Windows Phone, without having to log into your provider's website each time you want to send an SMS.

Features

- SMS History
- Contacts support
- Balance check on all the supported services
- Managing and sending SMS from multiple providers at the same time
- Switch between multiple account in one tap
- A beautiful user interface that looks and feels like the native WP7 SMS app.

Supported services

In order to user Beta SMS, you need an account with one of the following providers:

- SMS Global
- Cherry-SMS
- Sloono
- 12voip.com
- Actionvoip.com
- Calleasy.com
- Cheapvoip.com
- Dialnow.com
- Freecall.com
- Internetcalls.com
- Intervoip.com
- Justvoip.com
- Lowratevoip.com
- Netappel.fr
- Nonoh.net
- Poivy.com
- Powervoip.com
- Rynga.com
- Sipdiscount.com
- Smartvoip.com
- Smsdiscount.com
- Smslisto.com
- Sparvoip.de
- Voipbuster.com
- Voipbusterpro.com
- Voipcheap.co.uk
- Voipcheap.com
- Voipdiscount.com
- Voipgain.com
- Voipraider.com
- Voipstunt.com
- Voipwise.com
- Voipzoom.com
- Webcalldirect.com