Category Archives: General

Visit the primary web site at

This web site – – is no longer the primary web site for our App Inventor tutorials. However, this web site will remain here indefinitely as many people link to it, including search engines and my own e-books 🙂

The new, short and easy to remember URL is as in “Learn 2 Code”

Unfortunately, for reasons I will not get into, it is not possible to integrate the two web sites together. So will remain “as is”, and will become the primary focus point.

I am looking into having Learn2C automatically cross post to the web site but that has not yet implemented. But I’d like to do that for those that already follow the web site.

My apologies for not doing a lot of updates during 2018. I have already written some new code examples (Bluetooth LE anyone?) and am working on more in that area. These tutorials will appear once I have completed the entire series of example programs. There are also other items in the works that I cannot talk about yet.

Web site issues

First, the update to WordPress 5 did not go well with this web site. The web site is running WP 5 now but it has caused many problems, at least one of which I seem unable to work around or fix.

Second, I tried to reconfigure the web site for something I have been working on, but it appears what I wanted is not possible. This temporarily left the web site over night on 10 January 2019 (UTC) unable to handle incoming search links properly. I have backed out that change and search queries (via Google) should resume landing on the correct pages.

Third, around 31 December to 2 January, this web site was mostly inaccessible due to my ISP making a change to their network, which made their SQL database server inaccessible. This impacted multiple web sites, including the ISP’s own web site!

I am continuing to work on these issues with apologies for the inconvenience.

Most popular programming languages?

There are many surveys of programming language popularity. Many of the popular surveys have problems with the survey methodology such that they likely produce erroneous estimates of programming language popularity. For example, one survey looks at how many times each programming language is looked up on Internet search systems.

The chart, below, comes from GitHub and bases popularity on the number of “pull requests” that are made to the GitHub software repository. Using this method, JavaScript is the most popular programming language, followed by Python, Java, Ruby and PHP.

Python has become a standard for use by non-computer science students. Whether your college studies be in mechanical engineering or geology, there is a good chance you will learn Python for data analysis projects.

Java is now an old programming language, but still used especially for Android programming. It’s popularity for desktop applications is starting to diminish.

Ruby become popular about ten years ago. Ruby is based on a concept of “frameworks” that provide pre-made program skeletons which you adapt to make your own application. Ruby is very popular for quickly creating web-based applications.

PHP pre-dates Ruby – PHP is a script language that runs on the server side of a web application. PHP is very easy to learn and couples easily with MySQL databases, making the combination a great solution for web-based, database-backed applications.

Finally we get to the “C” derived languages including C, C++ and Microsoft’s cousin C# (a very powerful language with great development tools.). C dates back to about 1970 or so.

C++ was developed in the 1980s and added object oriented programming to C and has since expanded in many ways. C and C++ are commonly “compiled” into machine instructions for each CPU and are used for high performance applications, including operating systems, video games and media applications.

C# has features resembling Java and C++ – but in a more modern design. In some ways, C# is where some wish C++ had gone

Capture has moved to

In the spring of 2017, this web site – – was moved to (or an alternate address

The move was made for technical and practical reasons. Visit for updates made through out 2017 and into 2018.

However, things have changed since then and as of the spring of 2018, this web site may return to here. If that happens, the plan is for the new address to point here as well.

Why return?

Many of the technical issues that caused to migrate a year ago have gone away or been solved.

The web site is hosted at and it appears Google down ranks WordPress web sites in search results. This old site – even without having been updated in a year, continues to receive many times more visits as a result of searches than does the hosted web site!

Finally, WordPress raised their hosting price last year.


Is your Android battery life too short? Some ideas that might fix it

Periodically, my  Nexus 5 phone’s battery life is terrible. On good days, if I don’t use my phone, the battery discharge rate is slow – many hours later, the battery meter says there’s still over 90% of the battery charge remaining. But when it is bad, my unused phone can have its battery drain in 8 hours.

I have found two things to improve improve the battery life on my Google Android Nexus 5.

  • One is to clear the system cache partition – this cache setting is not accessible from Settings.
  • The other is to replace the Android launcher with Nova Launcher, available for free in the Google Play store.

How to Clear the System Cache Partition

To clear the system cache you need to enter a hidden Android start up menu, usually by starting your phone while pressing the power and volume control keys simultaneously. For specific instructions, see this explanation for the Nexus 5 (it might work on your phone too – this does work on my Nexus 5). Another list from a mobile phone service describes how to do this for other phones (I have not tested any of those).

Every few months, the battery life has gotten really bad. But after clearing the system cache partition, the phone returns to normal performance. I hope this works for you.

I noticed this might be related to my installing lots of apps on the phone, over and over again. Some days I’ll install my test app 10 or 20 or 30 or more times. After a few weeks of doing this every day, battery life problems develop. I clear the system cache partition and the phone is fine again.

You can learn more about the Android system partitions by reading this article.

Security: http versus https and access to the web site

As you may know, http is the old way to access a web site. https is the newer secure method that encrypts data sent to and from the web site.

Last year, Google announced it would rank search results such that web sites accessed via https rank higher than those using http.

This web page has been using http – which is okay since there is nothing secret or controversial about the content here.

However, on 7 March 2017, Firefox will launch an update that will issue a security warning when visiting web sites using http.

Consequently, we need to switch our web sites from http to https which involves paying a fee to buy an SSL security certificate and re-configuring software and servers.

I have successfully converted my web site to https as a test for the conversion. So far everything looks good.

I will eventually convert the web site to use https also. I do not have a date for that – it could be next week or the end of the month.  When I do the conversion, their might be a temporary period where you receive a security warning about accessing the web site, depending on how I do that update.