App Inventor programmers routinely store values, such as numbers or text strings (“Hello!”) in variables. For example, stores the numeric value 6 in to the variable TOTALBUTTONS. To illustrate by example, here is a global variable named SpecialButton. We can initialize it to anything we want at this point. Next, inside our app, our blocks … Continue reading Part 1: Storing and accessing user interface components as variables
This web site is now receiving 25,000 unique visitors each month! I am very pleased that these tutorials are helpful to so many people all over the world! Web site access is nearly the same every hour around the clock, implying a global readership (update: 145 countries!) Operating System Used 82% of the visitors use … Continue reading Appinventor.pevest.com usage
As you know, MIT App Inventor is a graphical-based programming system, or a “visual development” system where programs are constructed by dragging and dropping “blocks” onto a Blocks editor. Arduino, which we mentioned in conjunction with our Bluetooth interface code, is a microcontroller system that is normally programmed in a language similar to the C++ … Continue reading “Visual Development” system for Arduino
When I had a Nexus 4 running Android 4.3 and earlier, I used an app called Juice Defender to extend the time between battery charging. I often went 2 days without recharging the battery! But Juice Defender has not been updated since 2012 and due to Android changes, Juice Defender no longer works well. Then, Android … Continue reading Android battery life – and how to extend your battery power
Atmel introduced the new Arduino Zero controller board, which includes new support for Bluetooth, Wi-Fi and sensors, apparently (I do not yet have details). A couple of weeks ago, I showed how to use App Inventor and Bluetooth to communicate with an Arduino board. Here is a video clip about the new Zero controller board. … Continue reading New Arduino Zero controller board
Some times App Inventor 2 apps stop working (well mine sometimes do this, may be your’s don’t!) Besides looking carefully at your blocks code, there are some additional steps that may be helpful in identifying the cause of the problem. 1. Check your blocks code very carefully to see if you can spot an error in … Continue reading Identifying the cause of serious errors in App Inventor apps
