Antony’s Mobile Blog

These free booklets from Symbian are intended for developers. They discuss various development topics in hand and consie format. They are normally less than 100 pages long. The terms “free” here mean you can download it from Symbian web site and get the printed book for free.

Currently there are 9 booklets plus some translations to Chinese and Japanese and the list is growing. Here is the current list:

Essential Symbian OS booklets

• Signing Tips
• Coding Tips
• Performance Tips

Using Symbian OS booklets

• Getting Started
• Java ME on Symbian OS
• P.I.P.S
• Carbide.c++
• Data Sharing Tips

Essential UIQ booklets

• UIQ Essentials Getting Started

Recently I had a strange problem with my Nokia E61 device. The device needs to be charged every day. I was quite sure that the battery was still okay. The device was relatively new, about 1 month old. Before it happened, I could use my device for 3 - 4 days without charging.

I thought it must be from one of the applications that I have installed recently. I suspected one of the applications that I have just installed. Then, I decided to uninstall it (I am not going to disclose the name of the application). What happened after that? The problem with my battery was solved. I can use my device normally.

Why did it happen? Apparently, the application installed a server that runs in the background. I am not sure what the server is doing, but it empties the battery very fast.

As a mobile developer, how can we avoid this? Forum Nokia has a good paper, S60 Platform Effective Power and Resource Management. I won’t repeat everything here; just highlight some of the important points:

• Continuous timers, ticking too frequently (for example, more than once every five seconds), can adversely affect power consumption.
• If an application is moved to the background, it should, where appropriate, be paused and timers should be stopped.
• The backlight shall not be kept on without a good reason. It is turned off after a short period of inactivity is to conserve power; therefore overriding the system defaults should only be done if there is a compelling reason.
• Communication technologies, such as Bluetooth and WiFi, should be used carefully, as there is always some drain on the battery when any network interface is active.
• The camera has to be powered off when it is no longer used. Even if the camera is not being actively used, it is still consuming power if it is not powered off.

Please, always remember that mobile device has limited battery power. It is not the same as desktop world where the power is “unlimited”.

Last night, I took an exam to get a certification as an Accredited S60 Developer. For those who don’t know about Accredited S60 Developer:

The Accredited S60 Developer programme from Forum Nokia is an objectively measurable framework for continuous professional development for S60 C++ developers. It comprises a curriculum and pass criteria defined by Forum Nokia and an on-line assessment that tests knowledge and understanding of that curriculum, provided my Majinate Limited.

The pre-requisite to become an Accredited S60 Developer is that we have passed Accredited Symbian Developer exam, which is another exam to measure the competency of Symbian OS development. The complete curriculum for Accredited S60 exam is available on Majinate’s web site.

The exam basically contains 36 multiple choices questions. Each question can have up to 3 correct answers. We have to select all the correct answers. If we can select all of them, we will get point. If answer a question incorrectly or missing the correct question. Each question has different weight. It means we will get more points when we answer more difficult question.

The exam also uses Computer-Adaptive Testing (CAT) method. The difficulty level of the next question is based on our previous answer. If we answer it correctly, the next question will be more difficult; and vice versa.

How to prepare the exam? If you are interested taking the exam, I would recommend:

• eLearning Curriculum from Forum Nokia, which is available for free.
• A good S60 book would definitely help. I would recommend Developing Series 60 Applications from EMCC Software Ltd. This has been my favorite book about S60. Although it is written for S60 2nd Edition, most of the topics are still applicable for S60 3rd Edition.

• There is also a new S60 book, S60 Programming: A Tutorial Guide, which may be helpful too. Unfortunately, I don’t have this book yet, so I couldn’t comment further.

For those who are interested taking Accredited Symbian Developer exam, please check my previous posting.