Tag Archives: appinventor

App Inventor News, Components, Uncategorized

New App Inventor 2 “Companion” app released today; new features

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Changes between nb143i and nb144 (June 30, 2015)

  • When a component is renamed in the designer, any related collapsed blocks will be properly renamed now.
  • Screen1 now has properties that permit you to hide both the top “Status” and “Title” Bars
  • The selected item in a ListView is now highlighted
  • Activity Starter component now has a “Activity Canceled” event
  • Fix to the Player Component so it doesn’t spontaneously start playing after a phone call or other interruption
  • Bugfix to Image Sprite rotation which had left screen artifacts on some devices
  • Add Math blocks to convert between decimal, Hexidecimal and Binary representation
  • Clock Component now permits you to format a date or time arbitrarily. You provide a “format string”
  • You can now have both a Background Image and a Background Color and the “right thing” happens
  • TextToSpeech: The designer now uses dropdown menus to select Country and Language. Added blocks to fetch the supports countries and languages on a given device

Source: Release Notes for MIT App Inventor 2 (Beta)

Documentation, General, Products, STEM Education, Uncategorized

App Inventor 2 Tutorial Volume 2 is now available at Amazon

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Volume 2 of the App Inventor 2 Tutorial is now available at Amazon as an e-book via this link: App Inventor 2 Tutorial Volume 2: Step-by-step: Advanced features including TinyDB.  The e-book will also be available from Google Play shortly.

Description

MIT App Inventor 2 is a fast and simple way to create custom Android apps for smart phones or tablets. Volume 2 in the series introduces debugging methods, explains additional controls not covered in Volume 1, introduces “agile” methods for developing a real world app, and provides sample code for using the TinyDB database.

The App Inventor 2 Tutorial series is targeted at adult learners (high school and up). App Inventor 2 provides a simplified “drag and drop” interface to layout your app’s screen design. Then implement the app’s behavior with “drag and drop” programming blocks to quickly assemble a program in a graphical interface.

Volume 1 of this series covered the basics of the App Inventor user interface Designer and the Blocks programming editor, plus basic “blocks” programming concepts and tools for arithmetic, text processing, event handling, lists and other features. Volume 2 builds upon Volume 1 to provide tips on debugging programs when the apps work incorrectly, how to use hidden editing features, and how to install your own apps on to your phone or tablet for general use. Code samples are provided for using the Notifier component for general use or for debugging, for user interface control tricks such as buttons that change color continuously or implementing the missing “radio buttons” component, using ListPicker and Spinner for list selections, and using the WebViewer to display web pages in your app. The book includes a large section on designing and building a sample real world application and finishes with a chapter on using the TinyDB database.

For readers of the blog, Chapters 4–8 are based on the tutorial already presented here. Chapter 2 and Chapter 9 on TinyDB are all new material.

Chapters

  • Introduction
  • Chapter 1 – App Inventor Tips
  • Chapter 2 – Debugging App Inventor Programs
  • Chapter 3 – User Interface Control Tricks
  • Chapter 4 – Designing and Building a Real World Application
  • Chapter 5 – Tip Calculator Version 2
  • Chapter 6 – Tip Calculator Version 3
  • Chapter 7 – Tip Calculator Version 4
  • Chapter 8 – Tip Calculator Version 5
  • Chapter 9 – Using the TinyDB database

(Volume 3 is now available – App Inventor 2 Databases and Files adds substantially more information on TinyDB, plus TinyWebDB and Fusion Tables and includes the full introduction to TinyDB).

AppInventor_Volume2Cover

General, Products, Uncategorized

App Inventor 2 Tutorial volume 2 will be available in a few days

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Volume 2 of the App Inventor 2 Tutorial will be available at Amazon and Google Play/Google books within a few days. Just waiting for the new title to clear through their review process.

AppInventor_Volume2Cover

Products, Programming Method, Software, STEM Education, Uncategorized

“Visual Development” system for Arduino

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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++ programming language – which is text-based.

Mitov Softwware has introduced a new visual programming system for Arduino. I have not yet had a chance to try this out – the software is in “Beta” test phase and is not yet generally available.

The simplicity of an App Inventor type programming environment might then be available for Arduino applications. This is very exciting. It may be helpful for enabling more kinds of people, with different types of backgrounds than software developers(!) to write code for Arduino boards.

Program Arduino boards visually, fast and easy with Visuino #Visuino #Arduino

Source: Visuino – Visual Development for Arduino by Mitov Software

I have used this screen shot from their web site to illustrate the general idea – really looking forward to trying this out!

screenshot-03

General, Uncategorized

Subscribe to AppInventor.Pevest.com by email

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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.

Components, Programming Method, Tips, Uncategorized

Can you make a video player in App Inventor? Not really, unfortunately.

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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.

 

Software, STEM Education, Uncategorized

“Why Learning to Code is So Damn Hard”

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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.

Programming Method, Uncategorized

How to connect App Inventor apps to Arduino using Bluetooth wireless

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How to Connect App Inventor apps to Arduino Using Bluetooth

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.

What is Bluetooth?

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.

What is Arduino?

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.

HARDWARE: Setting Up Arduino for Bluetooth Wireless Communications

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.

DSC_1266Click 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 →

Programming Method, Uncategorized

Coming soon: Bluetooth to connect Android App Inventor code to Arduino

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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).

  • Use your phone or tablet to remote control an Arduino device over a Bluetooth link
  • Use an Arduino device to monitor remote sensors, and then link sensor inputs to an Android phone over Bluetooth
  • Conceptually, an Arduino device could monitor local sensors (temperature, humidity, security alarms), and transmit sensor data to an Android phone, which, in turn, could forward the data onto an Internet location.
Components, Uncategorized

Using TimePicker and DatePicker for entering time and date information

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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:

TimeDate_TimePickerUIThe 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 →