ev3dev-lang-java

EV3Dev-lang-Java is project to learn Java and create software for Mindstorms Robots using hardware supported by EV3Dev & the LeJOS way.

Introduction

In Lego Mindstorms ecosystem, the default solution to develop Java software for Lego Mindstorms was LeJOS but now exists one alternative, EV3Dev-lang-java a Java project running on the top of EV3Dev.

Lego Mindstorms ecosystem is a nice educational way to learn Java programming in general and Robotics in particular. Now, it is possible to install a complete Linux distro in the third generation of the product and others companies like Mindsensors & Dexter Industries has released products which interact with Sensors & Actuators from Lego ecosystem and that boards can use the Power of the popular board Raspberry Pi 3

But, with the help of EV3Dev, it is possible to have the same Linux experience for multiple boards. So... why not develop a Java library for that Linux Distro? The answer is EV3Dev-lang-java. The project, takes the good things of both worlds: EV3Dev with the complete linux experience and LeJOS with the rich local navigation stack and the remote support in the future.

What Debian versions are supported with this library?

The library has support for Debian Jessie & Debian Stretch. In this release, we have finished the support for Debian Stretch for EV3 and you could use OpenJDK 11 or OpenJDK 12 EA and it is amazing!

If you need to use any Raspberry Pi Boards, I recommend to use the stable EV3Dev Debian Jessie release.

What is the hardware platforms supported in this project?

Using the same Java objects, it is possible to deploy the software for Robots on EV3 Brick, Raspberry Pi 3 with BrickPi 3 & PiStorms.

#	Element	EV3 P-Brick	Raspberry Pi 3 Model B+
1	Hardware	EV3 Brick	BrickPi+, BrickPi3, PiStorms
2	SoC	TI Sitara AM1808	Broadcom BCM2837B0
3	CPU	1× ARM926EJ-S @ 300MHz (max 456MHz)	4× ARM Cortex-A53 @ 1400MHz
4	RAM	64 MB LPDDR	1024 MB LPDDR2 (900 MHz)
5	USB Host	1× USB 1.1 (without onboard hub)	4× USB 2.0 (from onboard hub)
6	Year	2010	2018

Project architecture

The project has been designed with the following solution in mind:

#	Layer	Option 1	Option 2
1	Platforms	BrickPi BrickPi3 PiStorms	EV3
2	OS	Debian Jessie	Debian Jessie/Stretch
3	JVM	OpenJDK 11	OpenJDK JRI 11 / 12 ea
4	EV3Dev Kernel	4.4.47-19-ev3dev-rpi2	4.14.71-ev3dev-2.3.0-ev3
5	ev3dev-lang-java	0.7.0	2.4.12

Note: At the moment, we will maintain the whole solution until the next LEGO Mindstorms product estimated for next January of 2020.

Features included in the whole project

Java features

OpenJDK Java 11/12ea support for EV3 Brick, Brickpi+/PiStorms + Raspberry Pi 3
Java profiling tools Support (Oracle mission control & JConsole)
Logging support based on SLF4J
Centralized logs with Kibana

Platform features

Support for EV3 Brick, PiStorms v1/v2, BrickPi+ & BrickPi 3

Lego Mindstorms features

Regulated Motor Support
Unregulated Motor Support
Sensor Support (EV3 sensors)
Sounds Support
EV3 LCD Support

Robotics

Automatic installation of OpenCV
eSpeak TTS (Text to speech) Support
LeJOS Sensor filter Support
LeJOS local navigation stack Support
RPLidar A1/A2 (2D Lidar) Support

Subprojects

Stable projects:

OpenJDK for EV3: A custom OpenJDK JRI/JDK (9,10,11,12) build for EV3
EV3Dev-lang-java: Low level integration with EV3Dev
lejos-commons: LeJOS interfaces & utilities
Installer: A set of Bash scripts to automate some operations with your brick
Template project: A Gradle project ready to test the project
Examples: A repository with several examples about the usage of this project

Incubator projects:

lejos-navigation: LeJOS navigation stack
Usb Devices: A library to use Arduino, Grove Sensors, GPS, IMU, LIDAR, and more devices...
ROS: A library to publish Sensor data to ROS for SLAM purposes