My Bluetooth Summer, not so BLE(h)

Hi there,

This last summer I developed Bluetooth Low Energy (BLE) interfaces for a couple of embedded boards and an Android app companion to operate the boards.

BLE Serial Console is currently in Beta and is available in Google Play.

Special thanks to Federico Biagioli who made the app’s Icon!

BLE Serial Console discovered all HM10 Services!

The app can discover all the GATT Services available in a BLE device. It was tested with an HM-10 module (in a breakout board) and Intel Edison’s HM11 integrated BLE module. BLE uses a protocol called Generic Attributes Profile (GATT), that exposes hierarchical data on any BLE device.

Once you enter the right GATT Characteristic, if it has Read/Write permissions you can exchange data with the module from the app to whatever device is connected to the BLE Module. Additionally, if the GATT Characteristic has the Notify permissions, you can subscribe to the device, and receive any updates made to that GATT Characteristic from the other side of the line. Subscribing will enable you to have bidirectional communication with the module.

HM10’s breakout board works with 3.3V with voltage and logic converters and exposes TX/RX pins that you can connect very easily to any Arduino based board having UART protocol. In my case I connected the RX/TX pins to the RS232 RX/TX pins in the CIAA board. HM10’s default GATT Characteristic contains a 20 bytes long registry with Read/Write/Notify permissions.

Service UUID: 0000ffe0-0000-1000-8000-00805f9b34fb
Characteristic UUID: 0000ffe1-0000-1000-8000-00805f9b34fb

EDU-CIAA-NXP & HM-10 BLE Module in Action

I wrote some node.js code for Intel Edison’s board. To enable BLE in this board you have to login and run 3 commands:

rfkill unblock bluetooth
killall bluetoothd
hciconfig hci0 up

After this, you can flash your javascript code to the board, connect & subscribe to the BLE device and operate seamlessly like any other Serial Communication app.

Last but not least, I wrote some plain twenty first century C code to interface with an embedded board called CIAA (Computadora Industrial Abierta Argentina). I connected an HM-10 BLE module to the board and configured the interface between a PC terminal, the board itself and the BLE module in Master Mode.


Bubblr updates for Android 7

Hello true believers!

I recently updated Bubblr’s Free and Full version, so you can enjoy using it with your Android Nougats!

Also, some of the updates include:

  • Auto dismiss buttons when clicking on them
  • Updated all the app-compat packages to 25.2.0
  • Bigger Icons 56 dp when not using FABs

Check them out!

Free Version:

Full Version (only 2 bucks!):

My Kotlin adventures: 5th Generation Language Awesomeness

Kotlin is a new programming language developed by the guys at JetBrains. Since it’s version 0.9 I’ve been testing the syntax and features and I must say that it’s amazing.

I developed a couple of Android apps which are now released in Google Play. Made 100% with Kotlin.

Bubblr is an application meant for the guy that wants a really fast shortcut to his everyday apps. it wants to be a very lightweight app launcher based on FABs (Floating Action Buttons). It is intended to be really simple to use and very lightweight (approximately 8 MB).The launcher adapts to the screen drawing an Arc of buttons that you can add, remove (swiping) and even sort by doing drag & drop with the buttons. Buttons are customizable, having the ability of being bubbles or icons within colored FABs (colors also customizable). The free edition has an Ad Banner at the bottom, safe and not intrusive. The Full edition doesn’t have Ads.

Augmented Fence (AFence) is an augmented reality fence, which uses Google Maps to display points stored in a sorted list, drawing a polygonal figure, and determining whether the user is inside or outside of the figure described by the polygon, and it allows you to activate alarms when the user is near the limits of the fenced area. The full edition doesn’t have any limitations.

To be able to develop these apps I used Android Studio with Kotlin’s plugin. The development was really faster y smooth than with other languages for Android, plus all the advantages that come from Functional Programming Languages, making your development experience more motivating and relaxing.

How many of you enjoy the term “tail recursion”? It’s like going into a traditional cafeteria and ask for a “mochaccino”, even though the tail recursion has been here since the days of Lisp and Haskell.

How about “pattern-matching” and “functional thread-safety”? These are some of the advantages of using a Functional Programming Language.

I think the world is going to make a leap of paradigm eventually, and staying in Java can be tough when that change happens. Java might be able to turn into COBOL… yuk!

It’s definitely the time to start giving 5th Generation Languages a chance, a try, and an APP.


Monkey Business – Xamarin Forms 2.3 Released

A new version of Xamarin Forms has been released, with a Xamarin Studio upgrade as well. These are very exciting news for cross platform developers wanting to have more control over the look and feel of their XF application without compromising quality and freshness.

Recently I tweeted about one of the features in XF 2.3, in context of one of Xamarin’s Contests.

I tested the new Native Embedding for Xamarin Forms Shared Projects. This feature is really interesting, as it lets you add components that aren’t fully cross-platform-ish into a Xamarin Forms specific platform, all this from within the Shared Code Project.

That’s inside a ContentPage, ContentView, or even a BoxView! Yay!

In the end I think it’s great news for developers, but maybe not so much for Project Managers, Product Owners, and any other management position. It’s a risk for them, because UI/UX designers usually operate with standard components and sometimes those components aren’t present in the other platform (iOS checkboxes, radio buttons, hello? hehe), and for the developer it’s sometimes confusing whether to complain about an over complicated flow which is cross-platform or to create 2 (two) separate workflows to have consistency with the platform itself. It’s a risk for managers, because in the end, the developer (the ones that figure there’s an existing 1 platform native component) tends to use these “hashtags” called preprocessor directives, making the compilation process of the application conditional to the specific platform. But, wasn’t this the one case the managers were trying to avoid, in favor of speeding cross-platform-ing?


To continue the fun part of this post, after a couple of weeks I received confirmation that I won the code-monkey plushy and here’s the end result of all this:

It’s clearer as days pass that it’s getting easier to be a good developer. If you are such one, convince your manager that too much cross-platform-ing can kill pandas, make kittens sad, and encourage global warming, and leveraging platform specific design strategies, save lives, and speed up the whole development process, and even may reduce the amount of Giphys sent in a day… LOL!

This is a very good step forward for developers to write awesome apps in C#, but beware the platform specific documentation… LOL

Again, thanks to #xamarin for the code-monkey and I’m looking forward to get into more of their contests.


Xamarin Forms Released

Hi all,

This is great news, Xamarin Forms NuGet package will get another big upgrade with 2.2.0 stable release.

I got notice about it because one of the bugs I reported about CarouselPage is in RESOLVED status. It seems that CarouselPage is going to be deprecated in favor of a new View called CarouselView.

I’m very excited about the amount of bug fixes and new features in 2.2.0 and I’m looking forward to test 2.2.0 stable release. Specifically, as an Android fan I’m looking forward to upgrade the Google Play Services packages to 29.x to have the latest packages and stay updated in the cross-platform world.

For more information on the bug fixes and new features in this pre-release version, check out the official release notes.

What do you think about this pre-release? Have you tried it yet? Let me hear your experiences in the comments section.

Xamarin Adventures of an Android guy

I’ve been doing cross-platform mobile applications for quite a long while now. I’ve done some PhoneGap apps, and Android apps, and now is the time for Xamarin.

Xamarin is a technology that’s growing fast, and as a mobile developer, is an unescapable career experience. With Xamarin I’ve been able to make iPhone apps for some clients and I’ve learned the importance of being a versatile -language agnostic- programmer.

It’s important to know how to achieve the same goals regardless of the platform you are a fan of, and being able to be as productive as you were without your usual tools.

That being said, it’s been also fun and challenging to try to integrate Java and Android technologies to the C# world. I personally used MonoDevelop in the past for doing some Mono projects back in 2008 but I never thought I would be using it this often. It’s fun how the jokes around Free Software and Privative Software start to mix into a "Dude, I know Object Orientation!" statement.

Who knows, maybe in ten years or less I end up coding in OCaml again, like in my college days in Coruña, Spain.

I hope to make a couple of posts in the future, featuring some Android + Xamarin crossovers. Definitely in time for Superman vs Batman crossover this week! Yay!


Academic Android Certification

I finished Coursera’s Mobile Cloud Computing with Android Specialization. It’s been a really wonderful experience to get through all the courses and the final capstone.

The Specialization starts with a first approach to all the basic features in Android’s API and from there, the course gets you through all the advanced features -Location Services, Security mechanisms for Intents, Sensors…- with the use of some optimized algorithms curated by the professors to help us learn the best practices for the these vast platform.

It also covers concurrency and design patterns used in multiple areas, not just Android, like ThreadPools and Queues for managing multiple parallel threads and synchronization, the Half Sync-Half Async pattern -used also in BSD Unix-, or Dependency Injection pattern -widely used in web application development- using Spring Framework. With concurrency, there’s a part in one of the courses that covers Networking, using Netty framework -one of the best frameworks in my opinion- for starting a Java web server without using the standard Servlet specs.

Finally, it covers the BackEnd too, with exercises using Spring 4’s framework. This last one has topics like HTTPS, OAuth2, RESTful Web Services -using RetroFit library- and best practices for using WebViews, helping us understand the whole picture when building Cloud Services for Android Applications.

The Capstone project was truly challenging, covering design documentation for Mobile + Cloud projects and deployments using enterprise PaaS products like OpenShift. It kept the focus on today’s industries needs and trending topics for mobile and cloud applications.

Overall, a great Specialization to do, recommendable to everyone willing to start in the Mobile development world and earn a lot of knowledge, with flexible times, and in the timespan of a year.

Special thanks to the professors from Universities of Maryland and Vanderbilt for this great specialization.