repository·master·Indexed 23 days ago
https://github.com/pi4j/pi4j-v1A Java I/O library providing Java programs with access, control, and communication capabilities for the core I/O features of the Raspberry Pi platform. Note that Pi4J Version 1.x is deprecated and archived; users are encouraged to migrate to Pi4J V2.0 for new projects. This documentation covers installation requirements, including OpenJDK 11 and unofficial WiringPi, as well as build instructions using Maven and Docker for Java and native libraries.
Pi4J Version 1.x is DEPRECATED and the repository is archived. For newer JDKs and Raspberry Pi models, you should use Pi4J V2.0.
If you are starting a new project, it is highly recommended to migrate to the Pi4J Version 2.x codebase instead of using 1.x, which is only maintained for major bug fixes.
libpi4j-armhf.so and libpi4j-aarch64.so) without building the Java JARs, use the --projects pi4j-native flag.If you want to build the entire Pi4J project without manually installing the JDK, Maven, or ARM cross-compilers, you can use the Pi4J builder Docker container. This container provides a consistent environment for all build steps. Ensure Docker is installed and running locally, then execute the commands from the root of the project directory.
docker pull pi4j/pi4j-builder:1.4
docker run --user "$(id -u):$(id -g)" --rm --volume $(pwd):/build pi4j/pi4j-builder:1.4To build both the Pi4J Java libraries (JARs) and the native libraries (libpi4j.so), use the native profile along with either the docker or cross-compile profile.
Building native libraries requires a cross-compiler environment. It is recommended to use the docker profile, which uses Docker containers to handle the native builds for 32-bit (libpi4j-armhf.so) and 64-bit (libpi4j-aarch64.so) ARM architectures, simplifying the process.
The original WiringPi library is deprecated. To support Raspberry Pi 4B and newer systems, you must install the latest unofficial version maintained at https://github.com/WiringPi/WiringPi. As of 2021-01-12, this is version 2.60.
sudo apt-get remove wiringpi -y
sudo apt-get --yes install git-core gcc make
cd ~
git clone https://github.com/WiringPi/WiringPi --branch master --single-branch wiringpi
cd ~/wiringpi
sudo ./buildYou can compile Pi4J locally using Apache Maven.
docker profile to build native libraries (ARMHF & AARCH64).Pi4J v1.x requires Java 11 (JDK) to build. Note that it may fail to compile with certain Oracle JDK distributions (e.g., 11.0.06, 11.0.07, 11.0.09, 11.0.10). It is recommended to use OpenJDK, Liberica, Zulu, or AdoptOpenJDK distributions.
sudo apt-get install openjdk-11-jdkTo build only the Pi4J Java libraries (JARs), run a standard Maven install. This command will not build native libraries; instead, it will use locally cached native libraries or download pre-compiled copies from the Maven repository.
mvn clean installYou can obtain Pi4J release builds through the following methods:
com.pi4j.Snapshot builds are available via Sonatype OSS or the official downloads page.
When building native libraries, you must specify which environment to use via Maven profiles:
| Profile | Description |
|---|---|
native | Instructs Maven to build the native libraries |
docker | Instructs Maven to use a Docker container to build native libraries |
cross-compile | Instructs Maven to use local cross-compiler toolchains to build native libraries |