Las ponencias fueron de los más variado, tuvimos a:

NEW IN HTML

As usual, this session presented by Paul Kinlan showed us the future of HTML5. I . . . → Read More: Google DevFest 2011 BCN]]> This week I assisted to the Google DevFest 2011 Barcelona. This year it was celebrated on a great “garage” located on an industrial area of Barcelona. I will tell the more interesting things that I found on the different sessions:

NEW IN HTML

As usual, this session presented by Paul Kinlan showed us the future of HTML5. I love the x-webkit-speech Chrome feature to make voice inputs that we already could see on the Madrid DevFest 2010. Paul made also some demos of WebIntents  a great idea to make something similar to Android intents on the web. Finally we could see that HTML5 is advancing very fast trying to implement many APIS that will make Flash obsolete, like window.navigator.getUserMedia() ot the Web Audio API.

GLSL

This session was presented by Mr. doob aka. Ricardo Cabello, a guy from the demoscene. He made a introduction of how 3D works in the browser and showed us how to use the GLSL language to make great effects on web pages. He has those GLSL demos on his blog.

GOOGLE+ SESSIONS

There were two Google+ sessions driven by Ade Oshineye, one presenting the new social network (also announcing the Google+ Pages) and other with more technical details for developers. One thing that you can do easily is adding the +1 button to your site. Other very interesting tools that we could see were the Google APIs Console and the Google APIs Explorer.

ANDROID SESSIONS

Bruno Oliveira is replacing Reto Meier as our “Android Developer Relations”.  On the first session he made a great review of the Android platform evolution since 2.1 to 4.0. On the second session he gave us great tips to improve UX experience on Android. This guy is a showman!

MAKING A BUSSINESS OUT OF APPS

This session was presented by Paul Kinlan and Bruno Oliveira, showing us that monetization tips are valid for both web and Android apps: Lazy registration, try before you buy, easy payment, in-app payments… Bruno also presented the new multilingual ”Guide to the App Galaxy” http://www.guidetotheappgalaxy.com/.

GOOGLE SHOPPING API

Daniel Hermes showed us the Google Shopping API and many integration samples.

CHROME DEV TOOLS

Finally Sam Dutton made a review of the Google Chrome development tools. This tools replaced my FireBug many years ago! He also made his slides available.

APP COMPETITION

This year Google also organized and Appcircus-style app competition. Those were the apps and sites presented:

• Ignacio Zafra - http://nubbius.com
• Pablo González Alonso - http://11870.com
• Joan Puyol - UK Weather
• Iñaki Villar -  Mallorca Beach
• Quim Garrigós - Striker Soccer
• FonYou
• TwoNav
• CityBikes
• And me with Mobialia Chess

I won the app competition, but all were great apps. Our presentation and some photos of the app competition are available at our Mobialia Blog.

So I will propose you a solution based on Android-X86. This is a project that . . . → Read More: Developing with Android-X86 2.3 and VirtualBox]]> One of the most tedious thing developing for Android is the lack of an efficient emulator. The bundled Android emulator with the SDK is very, very slow due to that it is emulating an ARM architecture over X86 processors.

So I will propose you a solution based on Android-X86. This is a project that ports Android to the X86 architecture and they recently released the 2.3 RC1 version. With VirtualBox you can create a X86 virtual machine and install Android-X86 on it.

First, install VirtualBox and create a virtual machine with the following specs:

• Operating System: Other
• 512 MB RAM and 5 GB HD (enough)
• Bridged Network (easier for the adb connect step)
• Emulating a Sound Blaster 16 sound card (trying it as recommendation from Android-X86, but at the moment it doesn’t work for me)

When you start VirtualBox by first time it will ask you for a boot CD, select the downloaded image. On start it will let you choose between running Android from the CD or install it on hard disk. Select install to hard disk, create a partition on the virtual disk, and install Android on the partition selecting  the “System read write” option.  During the installation process, you can create a virtual SD card (of 2GB maximum), the SD card is necessary for many apps to word.

Then you can now start your Android-X86 system (don’t forget to remove the ISO image). By default it will have the ethernet networking configured, you can check it at Settings->Ethernet configuration.

To start developing with this virtual machine, you need to connect it to your computer via adb. Android-X86 includes by default an adb server listening on port 5555. On the virtual machine get your IP address pressing “ALT-<F1>” and typing netcfg (press “ALT-<F7>” to go back to the graphic screen). Then, on your computer type

adb connect <IP>:5555

Replacing <IP> with your virtual machine IP. Now the emulator is connected with adb to your machine and you can run apps on the emulator pressing play on Eclipse or start a shell in the emulator with adb shell…

The Android X86 virtual machine is much faster than the emulator. Take into account that native apps will not work on Android-X86, but Google-TV is also X86 based, so it seems that the X86 platform will be longer supported on the future.

• Download android-x86-2.3-RC1-eeepc.iso
• Android-X86 2.3 RC1 release
• Virtualbox-Howto on Android-X86

Last week I was invited by Miguel Silva Constenla to the Blusens HQ at Santiago de Compostela. Blusens is a Galician consumer electronics manufacturer with worldwide presence.

I had a great expectation because Miguel said that was going to show us their upcoming Android devices. He received us at . . . → Read More: Upcoming Android Gadgets at Blusens]]>

LED TV Assembly Line

Last week I was invited by Miguel Silva Constenla to the Blusens HQ at Santiago de Compostela. Blusens is a Galician consumer electronics manufacturer with worldwide presence.

I had a great expectation because Miguel said that was going to show us their upcoming Android devices. He received us at their administrative office, but soon we went to their I+D facilities.

There I was impressed with a production line where their LED TVs are assembled, he also show us their logistic office (with their famous “Orgy of the Senses” poster), call center, repair center, and engineering offices. Finally we went to their showroom where their upcoming android devices were waiting.

First one is an 7″ Android tablet. This is a cheap low-end Android device with something different: a cover with an integrated keyboard. This keyboard is plugged by USB to the tablet. It will be available in about two months by about 160€.

CONS:

• Resistive Touchscreen: Miguel said us that a capacitive touchscreen will increase the price about 50€, but the experience with the touchscreen was quite bad.
• Android 2.x: (in the release date is going to be Android 2.3). This low-end devices do not support Honeycomb.

7" Blusens Android Tablet

• Lack of Android Market: This device is not certified by Google so it cannot include the Android Market app. The ROM installed on  the prototype had the SlideMe market, but I don’t consider it an alternative. The solution is to install manually the Android Market (copying GoogleServicesFramework.apk and Vending.apk from other device to the /system/apps dir), but needs some Android knowledge…

PROS:

• 160€ is a very low price, I think that this kind of devices are very appropriate for children or for people in countries where people cannot pay 400€ for a computer.
• Elegant cover with embedded keyboard: great for fast text input, answering emails on the go, etc… Transforms the tablet in a kind-of-netbook and compensates the bad experience with the touchscreen.
• Local repair center and customer support: you can buy a chinese tablet by this price, but you will not have the customer support and repair center in europe.

Blusens Android STB Prototype

The other device is an Android Set-top-box. Blusens has a great experience with their web:tv device and they are investigating to release a similar Android based device. They showed us a prototype running Android 2.2.

CONSIDERACIONES SOBRE GOOGLE CHECKOUT

En el Android Market los pagos se hacen a través de la plataforma Google . . . → Read More: Vender en el Android Market desde España]]> Por aclamación popular os cuento los requisitos legales para vender aplicaciones en el Android Market desde España. Me centraré en el caso de vender como trabajador autónomo, que de momento es como estoy facturando en Mobialia.

CONSIDERACIONES SOBRE GOOGLE CHECKOUT

En el Android Market los pagos se hacen a través de la plataforma Google Checkout. Hay que tener en cuenta que a través de Google Checkout tú le vendes directamente a los usuarios, es decir que si te lo pidieran tendrías que emitirle una factura (aunque nunca me pidieron una). En Google Checkout no tenemos facturas, sólo tenemos las órdenes de venta, que son como albaranes.

La entidad gestora de Google Checkout, Google Payment Limited (GPL) es una entidad intermediadora en el pago que no cuenta para nada (bueno sí, para enviarte el dinero).

ALTA EN HACIENDA

Para poder facturar hay que darse de alta en hacienda (modelo 036). Yo me puse en el epígrafe IAE 213 Ingenieros de Telecomunicación, cada caso personal tendréis que estudiarlo. En este formulario también escogí la modalidad de estimación directa simplificada.

ALTA EN SEGURIDAD SOCIAL

También es necesario darse da alta en la Segurida Social como autónomo (modelo TA.0521) escogiendo una base de cotización según la que pagarás una cuota mensual.  Yo estoy pagando a la seguridad social 223,92 euros mensuales con la base de cotización mínima. Aunque tengas otro trabajo en el que ya estés cotizando a la seguridad social, este trámite es impepinable.

Teóricamente si tu actividad no se considera “habitual” no tendrías que pagar esta cuota, y según la jurisprudencia vigente la actividad es habitual si generas más que el salario mínimo interprofesional. De todas formas podrías meterte en un lío si no la pagas…

TRÁMITES PERIÓDICOS

Al estar dado de alta con el 036, tenéis la obligación de presentar trimestralmente el formulario 303 de autoliquidación de IVA (pones facturas de compra, facturas de venta y pagas la diferencia de IVA entre las ventas y las compras. Anualmente también hay que presentar el formulario 380 (que es un resumen recapitulativo del IVA).

En la declaración de la renta, en la sección de ingresos por estimación directa, pones los ingresos, gastos, pagos a la seguridad social como autónomo y pagas por los beneficios dependiendo del tramo de renta en el que estés.

IVA DE LAS VENTAS EN ANDROID MARKET

Hay que pagar el 18% por ciento de IVA sobre las ventas que realices en el Android Market dentro de la comunidad económica europea. Llegar a esta conclusión no es sencillo, ya que hay que releerse el artículo 69 de la ley de IVA; estamos en el caso 2 (vendemos a particulares), excepción m. Los servicios prestados por vía electrónica. El párrafo que hay que releerse (el que está entre los números y las letras) es digno de una prueba de comprensión lectora.

Se puede configurar Google Checkout para que les añada el 18% a las ventas de Europa o descontárselo tú luego. Yo se lo tengo añadido a mayores porque así también le aparece desglosado el IVA en la orden de Google Checkout al comprador (en hacienda me dijeron que era mejor así) y también es más fácil sacar los impuestos a pagar desde los CSVs de Google Checkout.

Ojo que si un comprador europeo de vuestra aplicación fuera operador de IVA intracomunitario y os pidiera una factura no podrías cobrarle el IVA y además tendrías que darte de alta el el registro de operadores intracomunitarios de IVA, pero esto es improbable.

FACTURA DE COMPRA A GOOGLE POR LAS COMISIONES DEL 30%

Google no te manda ninguna factura, sólo tienes las órdenes de Google Checkout. Yo trimestralmente introduzco una factura de compra a Google Inc USA pagándole las comisiones que me descuenta de las ventas (30%). Esta factura es exenta de IVA, y Google debería mandármela, pero como no me la manda, me la “invento”, ya que me la está cobrando implícitamente.

FACTURAS DE VENTA A ADMOB

Las facturas de venta a AdMob (de los ingresos que generamos por publicidad) también están exentas de IVA, ya que es USA, no tienen mayor complicación.

FINALMENTE

Cuando facturéis más de 50.000 euros anuales considerad el montar una S.L., que compensa tributariamente hablando ya que pagaríais por impuesto de sociedades en lugar de por tramo de renta.

Recordad que yo no soy un experto fiscal, simplemente os estoy contando mi experiencia, por lo que agradeceré comentarios y correcciones.

This year I was invited to organize a workshop at the Mobile 2.0 Open Ideas event at Barcelona, on 16-17 June. With my experience developing Android apps at Mobialia and the social media integration on Martin Varsavsky’s RadioMe, I proposed the workshop:

Bulding Social Media Enabled Android Apps

This will be a 1-hour . . . → Read More: Mobile 2.0 Open Ideas]]>

This year I was invited to organize a workshop at the Mobile 2.0 Open Ideas event at Barcelona, on 16-17 June. With my experience developing Android apps at Mobialia and the social media integration on Martin Varsavsky’s RadioMe, I proposed the workshop:

Bulding Social Media Enabled Android Apps

This will be a 1-hour workshop In which I’ll provide some examples on how to integrate social media on Android apps, from the simple “Share” button to more complex integrations like using Twitter, LinkedIn or Facebook APIs, including logging-in with social media, etc.

I will try to do it interesting for developers and also for app designers who want to add cool social features to their apps. Slides and code samples will be available from the day of the event.

• Mobile 2.0 Open Ideas
• Building Social Media Enabled Android Apps at Mobile 2.0

AIRPORT

I arrived to Stansted Airport. Try to get a fligth to Heatrow or Gatwick. Stansted is 1 hour away by bus from London city center.

There are many bus companies from . . . → Read More: My London travel tips]]> This easter we were on London, it was a great experience and I want to share with you some travel tips:

AIRPORT

I arrived to Stansted Airport. Try to get a fligth to Heatrow or Gatwick. Stansted is 1 hour away by bus from London city center.

There are many bus companies from Stansted to London, the cheapest and fastest is Terravision (15£ with return, 14£ if you book online) but National Express (9£ single) has free WiFi.

CURRENCY

There are many currency exchange offices, but the best is to get cash on an ATM with you credit card. If your bank charges a small comission (ING Direct charges only 2.5%), is cheaper than the exchange offices.

BUS & UNDERGROUND

The city is divided into zones, all the city center is zone 1-2. You can get a “Day Travelcard” for zones 1-2 by 6.60£ (cheap compared to the 4£ of a single travel). You can buy it on the automatic machines at the entries of the tube (allows payment with credit card).

This travelcard also allows you to use the city bus on this zones (only showing the card to the driver). A great tip is to get the bus line 11, you will get a sightseeing arround the touristic zones by the price of a Day Travelcard.

CYCLE HIRE

One funny thing that you can do is to hire a bicycle on one of the many points along the city. You can do it with your credit card. First you must pay 1£ for the access to the cycle hire for 24 hours. Then, you get a cycle by obtaining a printed release code from the machine. This code is composed of “1″, “2″ and “3″ digits that you must type on the cycle dock to release it.

When you dock the cycle again the system charges you card with an amount depending of the time that you used the cycle. One hour costs 1£ and the prices lower as you use it more hours. By only 2£ you can get a cycle by one hour.

MUSEUMS

The British Museum and other public museums are free so don’t miss them. Quite curious that you can’t take photos with flash on the underground but the British Museum is full of unconscious tourists taking photos with flash and touching pieces from the ancient Egypt.

WIFI

It’s quite hard to find free WiFis on London, but there are lot of BT-FON spots, my advice is to became a FON member before traveling to London, buy “La Fonera” by only 39€ at http://www.fon.com and share your home ADSL. As a FON member you can use this WiFis for free.

ANDROID

As I cound’t find free WiFis (and at the moment I’m not a FON member), I dindn’t used a lot my phone. As now Google Maps has local cache, try to view maps of London City Center when online, they willl remain cached when offline. I also used the app London Underground Free but is wasn’t much more useful than a printed map.

HOTELS

We were on a Easyhotel room but I can only say that it was cheap. Easyhotel thinks that a “room with window” is an underground room with a window to a corridor without natural light. It’s also quite surprising to make fit a bed and a bathroom on 6m2.

First, let’s see an example of a XML layout . . . → Read More: Using styles on Android layouts]]> A very cool feature of Android that many developers do not know (at least me 6 months ago) is the possibility of using “styles” on Android XML layouts. This thing is similar to CCS on HTML and provides a method to simplify the XML design.

First, let’s see an example of a XML layout without styles, you can notice the need to repeat attributes and the difficulty of reading the XML:

<LinearLayout
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:orientation="vertical">
 <TextView
  android:text="@string/text1"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textStyle="bold"
  android:textColor="@color/white"
 />
 <TextView
  android:text="@string/text2"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textStyle="bold"
  android:textColor="@color/red"
 />
</LinearLayout>

But we can define styles grouping this attributes on the file res/values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
 <style name="VerticalLinearLayout">
  <item name="android:layout_width">wrap_content</item>
  <item name="android:layout_height">wrap_content</item>
  <item name="android:orientation">vertical</item>
 </style>
 <style name="WhiteText">
  <item name="android:layout_width">wrap_content</item>
  <item name="android:layout_height">wrap_content</item>
  <item name="android:orientation">vertical</item>
  <item name="android:textStyle">bold</item>
  <item name="android:textColor">@color/white</item>
 </style>
 <style name="RedText" parent="@style/WhiteText">
  <item name="android:textColor">@color/red</item>
 </style>
</resources>

Note te possibility of  inheriting styles, in this example “RedText” is inherited from the “WhiteText” style changing only the text color.

Our XML layout, with styles, gets reduced to:

<LinearLayout style="@style/VerticalLinearLayout"/>
 <TextView style="@style/WhiteText"
  android:text="@string/text1"
 />
 <TextView style="@style/RedText"
  android:text="@string/text2"
 />
</LinearLayout>

Finally,  you can see that I’m using colors (@color/white and @color/red) which must be defined on the file res/values/colors.xml (in a similar way to strings):

<?xml version="1.0" encoding="utf-8"?>
<resources>
 <color name="white">#ffffffff</color>
 <color name="red">#ffff0000</color>
</resources>

For me it was easier to implement Twitter API access using only the signpost library, for facebook they recommend to download their Android SDK, and I did so. First we . . . → Read More: A small problem with the facebook Android SDK]]> At Mobialia the lasts weeks I was involved on the development of a social app using, among other social networks APIs, the facebook API.

For me it was easier to implement Twitter API access using only the signpost library, for facebook they recommend to download their Android SDK, and I did so. First we need a class attribute with the Facebook object:

Facebook fb = new Facebook(appId);

The problem is during the autentication process: we must call the fb.authorize method…

fb.authorize(this, PERMISSIONS, ACTIVITY_CODE, this);

And wait for the result of this called activity on our onActivityResult method


protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    fb.authorizeCallback(requestCode, resultCode, data);
}

But, here is the problem, under heavy memory requierements (like testing on a old HTC Magic) the caller activity may be killed, and the status of the Facebook object is not maintained so the call to authorizeCallback is going to fail.

Then I need a method to mantain the Facebook object status, and here comes the hack. I added this method to the Facebook object:

public void setStatus(int mAuthActivityCode, DialogListener mAuthDialogListener){
    this.mAuthActivityCode = mAuthActivityCode;
    this.mAuthDialogListener = mAuthDialogListener;
}

And I call this method on my onActivityResult:

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    fb.setStatus(ACTIVITY_CODE, this);
    fb.authorizeCallback(requestCode, resultCode, data);
}

Note that the DialogListener is the same Activity. Other solution may be to avoid killing of the caller activity, but I don’t figure how…

This location methods can be enabled or disabled by the user on the preferences or with some widgets.

Initially on our apps we used . . . → Read More: Using two location providers on Android]]>
Android has two kinds of accuracy on location:

• Fine: provided by the GPS, needs some time to be obtained
• Coarse: location determined with the cell of the mobile network

This location methods can be enabled or disabled by the user on the preferences or with some widgets.

Initially on our apps we used only one LocationProvider with “Fine” accuracy:

• If the GPS was disabled it used automatically network-based location
• But if GPS was enabled, the location used it needing some time to be determined

As the data couldn’t be obtained until the location is determined, the app didn’t showed data, receiving this kind of error reports from some users.

The best solution that I found is to mantain two separated providers, with different precisions and receive location updates using both.

LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(false);
criteria.setPowerRequirement(Criteria.POWER_LOW);       

criteria.setAccuracy(Criteria.ACCURACY_FINE);
String providerFine = manager.getBestProvider(criteria, true);

criteria.setAccuracy(Criteria.ACCURACY_COARSE);
String providerCoarse = manager.getBestProvider(criteria, true);

if (providerCoarse != null) {
    manager.requestLocationUpdates(providerCoarse, 5*60000, 100, this);
}
if (providerFine != null) {
    manager.requestLocationUpdates(providerFine, 5*60000, 100, this);
}

You can also check if providerFine and providerCoarse are the same provider. When receiving location, the one received from providerFine must take precedence over the one from providerCoarse. Location’s provider can be obtained with location.getProvider():

public void onLocationChanged(Location location) {
     if (location.getProvider().equals(providerFine)) {
     ...

This is a trick that we are using on our Gas Stations Spain app and also on Wikiplaces (open sourced).

I developed a special app for this event called “Wikiplaces” and I made the code avaiable as open source on Google Code.

This app shows on a map or on a list places from Wikipedia near your location. . . . → Read More: Mobialia at LabAndroid]]> This week I was speaking at LabAndroid, a spanish initiative about Android devices, apps and development.

I developed a special app for this event called “Wikiplaces” and I made the code avaiable as open source on Google Code.

This app shows on a map or on a list places from Wikipedia near your location. I tried to include on it small code snippets for common things like styles on layouts, obtaining location, launching Google Maps Navigation, etc.

• Source on Google Code
• Page and Slideshow
• Article on and.roid.es

This is due to one of the biggest problems of . . . → Read More: Find Android apps with AppBrain]]> One of the first things that you can notice after buying an Android phone is the great amount of mobile applications (apps) that you can download from the Android Market, but searching for a specific app can be very frustrating, and a time-consuming task.

This is due to one of the biggest problems of the Android Market: the lack of a complete web interface to query the applications avaiable, and AppBrain is an independent web (not affiliated with Google) where you can list, search, etc. those apps.

There are many similar webs: Cyrket, Bubiloop, but Appbrain has some features which make the difference:

• You can sign-in on the web with your Google account
• Apps can be queried by country, genre (of the user), age range, etc.
• You can create list of apps and share it with your friends
• There is an android app (search for AppBrain on the Android Market) to synchronize your mobile with appbrain, and once installed:
• You can query the installed apps on your mobile
• You can install apps from the web

And everything with a very simple and pretty interface, so don’t wait to try it:

http://www.appbrain.com

HARDWARE

The event started with Dave Burke presenting Google Technologies in general. Many jokes about the iPhone (to show the Chrome2Phone . . . → Read More: Google DevFest 2010]]> As many of you know, this year I’m involved on Android with my project Mobialia. On February I was on the Android Developer Lab at Madrid and today I returned for the Google DevFest.

The event started with Dave Burke presenting Google Technologies in general. Many jokes about the iPhone (to show the Chrome2Phone extension he send a page about iPhone unlocking from Chrome to a Nexus One). He made the typical Sunspider Javascript Test comparation between a Nexus One with Froyo and an iPad. It also was quite impressive so see GWT Quake2 Port running on Chrome at 50 FPS and the new voice/camera input fields on HTML5.

Then the sessions where split on two lines, I assisted to the Android, Chrome&HTML5 and Maps related.

Our beloved Reto Meier was speaking at the Android Sessions, much more technical than on February’s Android Developer Lab (good!). On his first session he made a great presentation about good and bad practices developing Android Apps (I suggest every android developer to see it!), on the second he speaked in detail about Cloud to Device Messaging and vice-versa. He gave me lots of app ideas using this feature. Finally he swowed us proudly his new Samsung Galaxy Tab and encouraged us to adapt our applications to the new tablet devices.

There were also very short presentations of spanish app developers (eAdventure, LibreGeoSocial, Inmobilia, Sicad and great the one of AnderWeb!).

Next, Paul Kinlan speaked about Chrome Apps and Extensions, the App Store and HTML5 on detail. I’m also very happy to see the progression of HTML5 and how Chrome is leaveraging the innovation towards a better web. Quite funny to see a modified Pacman Doodle controlled with the acceleromers of the iBook. There was also a presentation of Fiabee showing their HTML5 app and Chrome extension.

On the last sessions with Josh Livni talking about maps and presenting the Google Maps API v3, I was very impressed with maps customization, Fusion Tables and the new Google Street view API possibiliting the creation of 360º photos and adding them on specific locations (as inside a bar!).

All the sessions where recorded on video and will be avaiable at the Google DevFest Madrid web site.

First of all I decided to leave Negamax and go with Principal Variation Search (PVS). Also decided to implement separate methods for root . . . → Read More: Tales of a chess engine developer]]> Chess engine development is one of the most brain-crushing activities I’ve been involved on the last years. Last nigths I was working again on my Carballo Chess Engine with some advances.

First of all I decided to leave Negamax and go with Principal Variation Search (PVS). Also decided to implement separate methods for root nodes, PV nodes and null window searches. On previous experiments PVS was performing worse than Negamax, but I discovered the reason: the aspiration window has some implementation issues with PVS: when the search for a move fails low at the root node the move must be researched enlarging the window.

I was very stranged of why Futiliy Pruning was not working for me, but finally discovered the reason: a simple sign change after evaluation was the reason! Also implemented to store the evaluation values on the Transposition Table (TT).

The next step: why Carballo searched much less depths than other engines, it was due to quiescence search. I was generating checks for the first 4 PLY’s of quiescence, but some other engines not, so this was the reason. I decide to generate only checks on the first PLY of quiescence and only for PV nodes. Also modified a bit the move generation to optimize for quiescence.

During this time also found many interesting bugs, I was storing on the TT the bound and not the score when failing high/low, also on PV nodes is better to use only the TT for ordering and not to return scores from it, this helps avoiding draws. Also found a serious bugs involving time management (was taking as reference opponent’s time) and with contempt factor on IID searches corrupting TT entries. Finally added a Pawn Push Extension and removed the Recapture Extension and now some extensions now depend of the node type.

Running some test tournaments, I hope to get some good results soon and add the improved engine to my Mobialia Chess.

Jim Ablett has published a packaged executable for my Carballo chess engine. He also made a pretty logo for it, shown here. Check his page to download executables for Carballo and a lot of other chess engines: Jim Ablett’s Winboard Chess Page. Thanks Jim for your great . . . → Read More: Jim Ablett’s Carballo packaging]]>

Jim Ablett has published a packaged executable for my Carballo chess engine. He also made a pretty logo for it, shown here. Check his page to download executables for Carballo and a lot of other chess engines: Jim Ablett’s Winboard Chess Page. Thanks Jim for your great work!

Also has many improvements on the interface and gameplay, which makes Mobialia Chess 2.0 the best chess app . . . → Read More: Mobialia Chess for Android]]> The new version 2.0 adds the support to play online on freechess.org (FICS). You can play against people all around the world and compare your chess knowledge. Thousands of hours of entertainment with this new version.

Also has many improvements on the interface and gameplay, which makes Mobialia Chess 2.0 the best chess app for Android.

Try it! The LITE version is free, and the complete version is avaiable for only 1.99 EUR at the Android Market.

Check all the Mobialia Chess for Android features at http://www.mobialia.com/chess

GWT is provided from Google to develop applications in Javascript programming in Java. It conterts the Java code to Javascript, and the application is run on . . . → Read More: Great GWT UI for Carballo Chess Engine]]> Lukas Laag has written me about his new  GUI for the Carballo Chess Engine  using the Google Web Toolkit (GWT) and his SVG Graphics Library for GWT, libgwtsvg.

GWT is provided from Google to develop applications in Javascript programming in Java. It conterts the Java code to Javascript, and the application is run on the browser, without any additional plugin.

This interface is quite better than the sample Applet from Carballo, it has move history, legal move hightlighting, and SVN graphics. It can be used from:

http://www.vectomatic.org/gwt/libgwtsvg-chess/libgwtsvg-chess.html

He also wrote an article explaining the difficulties of his project. Thanks Lukas for your work.