GitHub Actions:
This project contains a minimal example application which uses the Pi4J (V2) library and uses a digital output (LED) and digital input (push button). Full description is available on the Pi4J website
The goal of the example project is to show how to set up a Pi4J Maven / Gradle project for the Raspberry Pi.
The application needs a LED connected on BCM 22 and button on BCM 24.
This project uses Pi4J V.2 which has the following runtime dependency requirements:
- SLF4J (API)
- SLF4J-SIMPLE
- PIGPIO Library (for the Raspberry Pi) - This dependency comes pre-installed on recent Raspbian images. However, you can also download and install it yourself using the instructions found here.
This project can be built with Apache Maven 3.6 (or later) and Java 11 OpenJDK (or later). These prerequisites must be installed prior to building this project. The following command can be used to download all project dependencies and compile the Java module. You can build this project directly on a Raspberry Pi with Java 11+.
mvn clean package
You can also use the Gradle Build Tool from these same sources. Use version 6.6 (or later) and Java 11 OpenJDK (or later). The Gradle wrapper is used as described on docs.gradle.org".
On Linux:
./gradlew build
On Windows:
gradlew.bat build
Once the build is complete and was successful, you can find the compiled
artifacts in the target (Maven) or build (Gradle) folder. Specifically
all dependency modules (JARs) and a simple run.sh bash script will be located in the
target/distribution (Maven) or build/distribution (Gradle) folder.
These are all the required files needed to distribute (copy) to your
Raspberry Pi to run this project. If you are using the native bindings running
locally on the Raspberry Pi, then you make have to run the program using sudo
to gain the necessary access permissions to the hardware I/O.
This is the list of files created by the build process of this example application:
- pi4j-core
- pi4j-example-minimal
- pi4j-library-pigpio
- pi4j-plugin-pigpio
- pi4j-plugin-raspberrypi
- slf4j-api
- slf4j-simple
- run.sh --> this is the actual start file which will run pi4j-example-minimal
Make the run script executable and start it like this:
chmod +x run.sh
sudo ./run.sh
Pi4J Version 2.0 and later is licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.