As they point out, the cyclical ups and downs in usage suggest App Inventor is primarily used by students – with drop off in usage during school vacation periods.
That suggests an opportunity to expand usage of MIT App Inventor – by insuring that AI2 appeals to a wide audience of potential app developers and not just educational programs!
I have added a new “Subscribe by email” feature to provide another way to be alerted to new posts on this web site.
Look for “SUBSCRIBE TO POSTS BY EMAIL” in the right column of this page, then enter your name and email address and click on Subscribe.
Check your email for a confirmation message and click on the link in the email to confirm your subscription. If you do not receive a confirmation email within a few minutes, check your Spam mail folder – and then check to make sure you entered your email address correctly!
I have only tested this feature with my own email address but hopefully it will work well for anyone who wishes to receive post alerts via email!
Facebook is a simple way to be alerted to updates, but you may also wish to use Twitter, our RSS newsfeed, or the new email subscription – or all of them! My intent is to make it simple for you to receive new posts in what ever way works best for you.
A question from a reader: Can we make a video player in App Inventor?
The short answer is, unfortunately, not really.
In the App Inventor Designer, in the Palette’s Media section, you can drag a Video Player into the viewer. But this Video Player only plays video files (WMV, MP4) that are stored inside your app (not on the web) and these files are limited to just 1 megabyte in size. Therefore, the Video Player feature in App Inventor is so limited as to not be very useful for most applications.
Click through for the full post at Viking Code School – as they say, the early part can be easy, then things get tougher, followed by a challenging learning period – until confidence and skills flourish.
What every beginner absolutely needs to know about the journey ahead
Source: Why Learning to Code is So Damn Hard
MIT App Inventor makes many things easier – but eventually one must learn to think like a software developer and become familiar with concepts like data structures, algorithms, design patterns, and software engineering design and project management.
Bluetooth is a low power, short range wireless technology built in to many phones, tablets and other devices.
MIT App Inventor 2 supports a set of Bluetooth communication functions that may be used to send data between smart phones and tablets (see previous tutorials: Part 1, Part 2)
This capability may be extended so that App Inventor apps can communicate with Arduino-based devices and other embedded systems.
This tutorial describes how to interface App Inventor apps running on Android to Arduino devices, via the Bluetooth wireless link.
Bluetooth is an industry standard for low power, short range wireless communications between devices such as personal computers, printers, smart phones, tablets, wireless headphones, wireless stereo speakers, sensor systems (like in security alarms) and other applications.
To learn more about Bluetooth technology (and why it has a funny name!), please read our first tutorial on Bluetooth.
Arduino is an open hardware, open software platform for building small electronic devices. The Arduino board is a “microcontroller” – that is, a complete – albeit small, inexpensive and with limited function – computer. Arduino is a popular choice for do-it-yourself projects and is well established in the “Maker” community of DIY project builders. (Side note: I will be at the San Francisco Maker Faire on Saturday, May 16th, 2015).
This is not a tutorial about Arduino boards, software or electronics and presumes the reader is familiar with Arduino development. To learn more about Arduino (and you should learn more about it!) start at the Arduino web site.
This tutorial assumes you have the Arduino software development environment installed on your computer and are familiar with Arduino development.
There are several versions of the Arduino board; I used the Uno version but others should work just fine.
The Arduino board does not contain Bluetooth hardware – to implement Bluetooth requires using a third-party Bluetooth module. I use the JY-MCU Bluetooth module . IMPORTANT – not all Bluetooth modules will work with App Inventor! While new versions of Android support all versions of Bluetooth, App Inventor (at the time of this writing) supports “classic” Bluetooth only. In particular, App Inventor does not support the newer Bluetooth LE (Low Energy) version, at least it does not support the Bluetooth LE module that I have.
I can confirm that the JY-MCU Bluetooth module works but the Bluetooth LE modules I have do not work with App Inventor. My phone can see the Bluetooth LE device but the App Inventor source code cannot communicate with the LE devices.
Where to buy the JY-MCU Module online: Amazon (Prime), Amazon (non-Prime)
The module is also available from other vendors.
Photo shows my Arduino UNO board, at left, a prototyping breadboard with a status LED set up, and the JY-MCU Bluetooth module, just above the breadboard.
Click through to see how the Arduino and Bluetooth module are setup, and get the Arduino source code and the App Inventor source code!
Continue reading How to connect App Inventor apps to Arduino using Bluetooth wireless
I have an App Inventor app running on my Nexus 5 and talking to an Arduino board via Bluetooth. I finally had a chance to work on this!
UPDATE: Here is the link to the final code and tutorial information!
What I have now is some experimental code not suitable for posting online. I will be revising this code to turn it into a simple example that will provide basic functionality, and then present a tutorial on putting it to use in your own applications.
Update Tuesday Cinco de Mayo (in the U.S.): I have the demo code up and running. Next up is to test and write up the tutorial! It’s coming! The first tutorial will be simple – intended to get you up and running. I will eventually create some more advanced features.
Longer term, I may create a more general solution for passing data packets back and forth between an Android App Inventor app and an Arduino board, so that many types of applications may be supported using my basic code library.
Arduino is a small microcontroller board used by hobbyists and others to add computing to small devices, art projects, robots, Internet connected devices and much more. Arduino is not part of App Inventor. Arduino is, for an “embedded system” easy to use in terms of building electronics hardware and writing control software. By writing App Inventor code to talk to an Arduino board, we open an entire world of new possibilities using simplified development (App Inventor on Android, and Arduino on the hardware side).
As you may know, you can save your App Inventor project to your local computer using the Projects | Export selected project (.aia) to my computer menu option:
Use this feature to save a backup copy on your local computer or to share your code with others (email or transfer the file using DropBox – or similar – or merely copy to a USB thumb drive).
Surprisingly, the .aia file is just a regular .zip file. You can verify by saving a copy to your local disk drive, and then rename the file to have a .zip file extension instead of .aia. Then use Windows Explorer, StuffIt Expander or other utility to open and decompress the .zip file.
PLEASE NOTE – DO NOT MODIFY THE CONTENT OF THESE FILES. THIS INFORMATION IS NOT SOMETHING YOU NEED TO KNOW TO WRITE APP INVENTOR APPS AND IS PROVIDED “AS IS” “FOR YOUR INFORMATION” ONLY.
The TimePicker and DatePicker User Interface Controls
Entering the date and time are common features of business applications. We could use a text edit box and let the user type in times (like 10:30) or dates (12 January 2015) but both methods require the user to enter the time or date in the proper format – and the app needs to test the entered data to ensure it was entered correctly.
A better solution is to use App Inventors TimePicker and DatePicker controls. Both provide a graphical method of selecting input values. For example, the TimePicker displays the following:
The time is set by pressing the + or – buttons above and below the hours and minutes. The AM/PM indicator is a toggle – when it shows PM, a press changes it to AM, and when it shows AM, a press changes it to PM. With this input system, the user can never entered an invalid time (the user could, of course, enter the wrong time, but that is a different problem!)
Continue reading Using TimePicker and DatePicker for entering time and date information
Last year, I presented a short tutorial on displaying web pages from inside your App Inventor apps. Now, here is a some what improved version that prompts for a web address URL, checks to see if http:// has been entered, and if not, prepends http:// to the front of the address. Then the web page is displayed.
There is not much to the user interface – a text box to enter the web URL and a button to display the web page. The page then appears below the button, and the content may be scrolled on the screen.
To create this user interface, drag a horizontal layout onto the screen and then add a label for the “Web page URL” prompt, followed by a text box for the data entry. Then add the Display web page button.
From the User Interface section of the Palette, at the left of the Designer screen, drag and drop a WebViewer component on to the design area.
The WebViewer is not a full Internet browser – it is a component that displays the specified web page only. The WebViewer does not support standard browser features, such as saving web page content nor does it provide a history of the web pages visited.
Part 1 of this tutorial introduced Bluetooth communications and implemented a simple method of sending text data back and forth between two Android devices over the Bluetooth wireless link. If you are not familiar with using App Inventor’s Bluetooth component, start with Part 1.
In Part 2, a data packet concept is introduced to guide the communications between devices, and is used to send a combination of text and numeric data. This section introduces the concept of binary numbers so that you can understand why we would handle text and numbers in different ways.
This tutorial modifies the user interface of both the client and server programs introduced in Part 1. Then, blocks code is added to send text and numeric data. Numeric data is sent as binary data using special methods of the Bluetooth components.
Related:
Related:
Continue reading Part 2: Sending numeric data using App Inventor Bluetooth communications
App Inventor 2 - Learn to Code (Learn2c.org) 