Easy Recipes for Building Android Apps using MIT App Inventor

Posted on by

MIT App Inventor

To help make Android App building more accessible to EVERYONE, researchers at MIT have released a wonderful tool to empower makers and students to quickly build apps using a puzzle metaphor of programming.  Everyone can play with puzzles.   Right!?   MIT App Inventor, originally developed by Google, enables beginners to create applications in hours.  (not days)   The MIT App Inventor enables you to test your apps in real-time using your Android device.   Additionally, you do not need to install special tools on your system since the development environment is browser based.  To learn more about this tool,  visit http://appinventor.mit.edu or AppInventor.org .   If you love Scratch and the work of MIT’s life long kindergarten, you’re going to love this!

The following videos by David Wolber of AppInventor.org, help you quickly learn how to design a small drawing application for your Android device.   David also offers a pretty nice book on App Inventor on his website.

Building the user interface:

Programming using Puzzle Pieces:

To help inspire you to build your own Android Apps with MIT App Inventor, we’ll introduce a few short recipes that you can include in your own designs.   These recipes will show you how to use the following device features:

  • Speech To Text
  • QR Code Scanning
  • Simple Canvas Drawing
  • Device Geo-location
  • Web browser

Let’s get cooking!    

 

Speech To Text App
“Speech To Text” app converts the voice the user into text by simply pressing a button and speaking.

Ingredients for App:

  • 1 Button
  • 1 Text Box
  • 1 Speech Recognizer

Here’s the program:

When the user clicks the “recognize_button”, then the speech recognizer tool gets called.   After the speech recognizer receives a result, we append the text to “TextBox1.”

QR Code Scanner App

This app enables the user to scan QR codes.   If the QR code represents a valid website link, the site will be loaded in the browser.

Ingredients for App:

  • 1 Button
  • 1 Bar Code Scanner
  • 1 Web Browser Control

Here’s the program:

The program is started when the user selects “scanButton.”   After the scanner has recognized the QR code, then the system commands the web browser to load the web site link.

Drawing App

This recipe enables you to create a drawing application for your Android device.

Ingredients for App:

  • 1 Button
  • 1 Canvas

When the user drags their finger over the canvas, a small green circle is drawn.  While dragging your finger on the canvas, the system will set the color of the paint to green.   The program draws a small circle at the (X,Y) coordinates of the dragging event.   When the user clicks the “clear_button” button, the device clears the drawing canvas.

Here’s the code:

Location Finder

This recipe shows you how to discover your current address using your location and place it on a Google Map.

Ingredients for App:

  • 1 Button
  • 1 Text Box
  • 1 Web Browser

Here’s the code:

When the user clicks “getAddress”, the system fetches your current location and finds your address.   Your address is placed in the “address” text field.   After that, we combine the Google maps search tool URL with your address.   This recipe isn’t perfect since it’s hard for Google to infer your street address perfectly.    It, however, shows you how to build mini-programs that use your current address or your current latitude and longitude. 

This post only scratches the surface.   App Inventor also includes puzzle pieces for Lego mindstorm, recording sound, taking pictures, and interfacing with Twitter.

We enjoy hearing from our readers.   If you build something cool with App Inventor, please let us know what you built!    

Featured Posts on InspiredToEducate.NET