Trisha Gee (Coder, blogger, speaker, Developer Advocate at JetBrains, @trisha_gee), which I interviewed for “Chapter 4: Choosing an IDE”, and Josh Long (Spring Developer Advocate at Pivotal, @starbuxman) worked together on a blog series in which they showed the power of reactive data produced by a Spring application. Instead of repeating a REST call each time you want to get data from the server, you do one call which returns a continuous stream in which new data is pushed based on an interval.

In my book I explain the use of bits and bytes by using a shift register SN74HC595 IC and 5101AS LED number display.

To create some timeline images for my book, I created this little JavaFX application to be able to easily update the content and recreate the image. Of course you can do the same in an image editor, but hey I’m a programmer and lazy, so I want a program to do the job for me ;-)

Using the Java library I created (see previous post), it was a piece of cake to create a JavaFX UI on top of it!

Next step in my book progress, is getting more into the details of hardware components. And as always starting with the smallest most-used ones: resistors!
To be able to fully document this for the book and create a demo application, I started again with creating and sharing a Java library.

The best way to understand and learn something new, is to document it yourself. That’s what I’m doing in every step for my book-in-progress. And to fully get the pinnings and headers of the different Pi-boards, I decided to gather all info into a Java library with different enums to be able to auto-generate some content for the book and use in a few different example applications.

I first learned about the “WAF” at work during a lunch discussion between engineers, on self-made domotica projects. Apparently the major reason such a project fails or succeeds is the “Wife Acceptance Factor”. According to some, the same WAF is the most critical point in every decision when buying a new television, radio or any electronic device with a complex remote control.

One of the example applications in my book “Getting started with Java on the Raspberry Pi” combines a JavaFX application with Mosquitto on the Raspberry Pi to control a LED strip with an Arduino. All wireless and independent of each other as the Mosquitto-queue is dealing with exchange commands between all applications.

A story of bits, bytes, signed and unsigned

Some time ago there was a question on the Pi4J-forum caused by some confusion about a numeric value handled as a byte which was logged as a negative number -86 instead of the expected value 170. So this is my attempt to try to solve this mystery… ;-)

My very first open source JavaFX library is now available in the Maven repository! A small step for mankind, one giant leap for myself ;-)