Java on the Raspberry Pi: Previous knowledge on electronics

Hi Frank DelPorte,

I already know Java but I'm novice on electronics. It this book right for me or should I have previous knowledge on electronics/Raspberry Pi to be able to get everything from the book?
How do you recommend to start for a newbie in electronics?

Thanks.

Hi Jorge, that was exactly my starting point when I started working on the book! I had an electronics kit, but only very minimal experience with it, and wanted to learn how to control those components with Java. So the book takes you through various examples to learn how different types of components need to be controlled (on/off, SPI, I2C, Serial,...)

This is the list of components used in the book:
https://webtechie.be/post/2022-11-17-javaonraspberrypi-shopping-list/

Frank

Thank you Frank.

It is amazing having the shopping list you share. Sometimes book writers take for granted this sort of things.

Impressive. NeoPixels! Looks like there are some serious projects there.

A quick intro to anyone thinking about interfacing hardware to the Pi:

A lot of the IoT (Internet of Things) gadgets you can get use one or more of 3 primary communications standards:

Serial (yes, just like COM ports)

I2C, also known as IIC.

SPI.

The PI OS has both built-in and standard add-on driver and library support for a lot of the thing you'd want to do with the Pi. You may have to first enable the interfaces themselves using the Pi config application, though.

The absolutely essential thing to bear in mind is that you'll be using the Pi's GPI pins to connect those devices and they absolutely MUST run on 3,3V signal levels. Many IoT gadgets run on 5V signal lines, though this is becoming less common. RS-232 serial can actually send as much as +/- 15 volts. So if you want to avoid fried Pi, make sure that you either have 3.3V logic devices or use a level shifter. IIC also allows multiple devices using the same signal lines, and may need termination resistors.

you might have to consider this:
https://pi4j.com/pi4j-os/

it could help a lot to start.

Igor De Souza wrote:you might have to consider this:
https://pi4j.com/pi4j-os/

it could help a lot to start.

It's worth noting that as a general rule, talking to non-traditional I/O devices in Java fails because Java's "write once/run anywhere" policy doesn't allow Java code to talk directly to memory-mapped I/O, I/O ports, or interrup service routines. The Pi4J distro, however, includes a set of JNI classes specifically aimed at getting around that.

It would be interesting to know if Pi4J-OS is capable of being ported to the "Pi clone" SBCs such as Orange Pi or BeagleBone. I had to port a project from Pi to BeagleBone during the Great Pi Shortage because at the time there was no shortage of BeagleBone Black units and they were adequate to the task. And it wasn't difficult. But that was C code, not Java.

Current version of Pi4J (V2+) only has implementations for Raspberry Pi to reduce complexity of building and testing...
But from architecture point of view, everything is available to add a module for other boards.

https://github.com/Pi4J/pi4j-v2/blob/develop/plugins/pi4j-plugin-raspberrypi/src/main/java/com/pi4j/plugin/raspberrypi/platform/RaspberryPiPlatform.java