Platform-independent serial port access for Java
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README.md

jSerialComm

A platform-independent serial port access library for Java.

Usage

For usage examples, please refer to the Usage wiki.

In order to use the jSerialComm library in your own project, you must simply include the JAR file in your build path and import it like any other Java package using import com.fazecast.jSerialComm.*;.

Alternatively, you can automatically add jSerialComm to your project as a dependency from the Maven Central Repository. Use the following dependency declaration depending on your build system:

  • Maven:
<dependency>
  <groupId>com.fazecast</groupId>
  <artifactId>jSerialComm</artifactId>
  <version>[2.0.0,3.0.0)</version>
</dependency>
  • Ivy:
<dependency org="com.fazecast" name="jSerialComm" rev="[2.0.0,3.0.0)"/>
  • Groovy:
@Grab(group='com.fazecast', module='jSerialComm', version='[2.0.0,3.0.0)')
  • Gradle:
compile 'com.fazecast:jSerialComm:[2.0.0,3.0.0)'
  • Buildr:
compile.with 'com.fazecast:jSerialComm:jar:[2.0.0,3.0.0)'
  • Scala/SBT:
libraryDependencies += "com.fazecast" % "jSerialComm" % "[2.0.0,3.0.0)"
  • Leiningen:
[com.fazecast/jSerialComm "[2.0.0,3.0.0)"]

Troubleshooting

If you are using Linux and this library does not appear to be working, ensure that you have the correct permissions set to access the serial port on your system. One way to test this is to run your application as root or by using the sudo command. If everything works, you will need to either run your application as root in the future or fix the permissions on your system. For further instructions, refer to the Troubleshooting wiki.

On some very few systems which use custom ARM-based CPUs and/or have extremely restrictive permissions, the library may be unable to determine that the underlying system architecture is ARM. In this case, you can force the library to disable its auto-detect functionality and instead directly specify the architecture using the Java os.arch_full system property. Acceptable values for this property are currently one of: armv5, armv6, armv6-hf, armv7, armv7-hf, armv8_32, armv8_64, x86, or x86_64.

An additional note for Linux users: If you are operating this library in event-based mode, the LISTENING_EVENT_DATA_WRITTEN event will never occur. This is not a bug, but rather a limitation of the Linux operating system.

For other troubleshooting issues, please see if you can find an answer in either the Usage-Examples wiki or the Troubleshooting Wiki.

If your question is still not answered, feel free to open an issue report on this project's GitHub page, and we will be glad to look into it.

Building

Building this library yourself is not advised (at least not for distribution) since it requires native compilation across multiple platforms. It is recommended to simply use the pre-built jSerialComm library in your application. For installation/usage instructions, please skip to the usage section.

If you do choose to build this library for your specific system, the recommended methodology is to use Gradle coupled with the Java SDK, version 1.6 (for backward compatibility).

Once the Java SDK 1.6 has been installed, ensure that you have an environment variable called JDK_HOME set to the base directory of your JDK installation. Once this has been done, refer to the section corresponding to your specific Operating System for further instructions.

Please note, if you would like to edit any of the source code or view it in an IDE (such as Eclipse), you can automatically build the Eclipse project files by entering the following on a command line or terminal from the base directory of this project:

gradle eclipse

You can then Import the project using the "Existing Project into Workspace" import tool in Eclipse. (Note that if you use Eclipse as an IDE, you will probably want to install the Eclipse CDT plugin for proper handling of the C source code).

Linux/UNIX

Ensure that the following tools are installed on your Linux distribution:

# On some distros, these may be called multilib tools for gcc and binutils
gcc make glibc-devel.x86_64 glibc-devel.i686

Ensure that the JDK_HOME environment variable has been set for the 1.6 version of your Java SDK. The correct directory can usually be found by entering the following command:

readlink -f /usr/bin/java

Export the result of this command up to but not including the /jre/... portion using the export command. For example, if readlink produced /usr/lib/jvm/java-6-jdk/jre/bin/java as an output, the export command would look like: export JDK_HOME=/usr/lib/jvm/java-6-jdk

Run the following commands:

cd src/main/c/Linux
make
cd ../../../..
gradle build

The resulting jSerialComm library can be found in the project directory build/libs under the name jSerialComm-{VERSION}.jar.

ARM-Based Mobile Linux (non-Android)

Ensure that you have a cross-compiler installed on your Linux distribution capable of compiling for ARM-based architectures. I prefer crosstool-ng for this purpose.

Ensure that the JDK_HOME environment variable has been set for the 1.6 version of your Java SDK. The correct directory can usually be found by entering the following command:

readlink -f /usr/bin/java

Export the result of this command up to but not including the /jre/... portion using the export command. For example, if readlink produced /usr/lib/jvm/java-6-jdk/jre/bin/java as an output, the export command would look like: export JDK_HOME=/usr/lib/jvm/java-6-jdk

Run the following commands:

cd src/main/c/Linux
make arm
cd ../../../..
gradle build

The resulting jSerialComm library can be found in the project directory build/libs under the name jSerialComm-{VERSION}.jar.

Android

Ensure that the Android NDK is installed on your system. For purposes of these instructions, assume that it is installed at {NDK_HOME}.

Run the following commands in order:

cd src/main/c/Android
{NDK_HOME}/ndk-build
cd ../../../..
gradle build

The resulting jSerialComm library can be found in the project directory build/libs under the name jSerialComm-{VERSION}.jar

macOS X

Ensure that Xcode is installed on your system. If it is not, it can be downloaded via the App Store. You must also make sure that the Xcode Command Line Tools are installed. This can be done by entering the following command in a terminal: xcode-select --install

Run the following commands in order:

cd src/main/c/OSX
make
cd ../../../..
gradle build

The resulting jSerialComm library can be found in the project directory build/libs under the name jSerialComm-{VERSION}.jar

Windows

Ensure that the Visual Studio C++ Compiler is installed on your system.

On Windows, the Visual Studio Compiler must be configured to build either 32- or 64-bit binaries but never both at the same time. Therefore, you will have to build binaries for the two architectures separately.

Open a command prompt and run the following command:

SET VC_DIRECTORY="C:\Program Files (x86)\Microsoft Visual Studio [version]\VC"

where [version] matches the version of the Visual Studio C++ Compiler that is installed.

Then run:

PUSHD src\main\c\Windows
%VC_DIRECTORY%\vcvarsall.bat x64
nmake win64
%VC_DIRECTORY%\vcvarsall.bat x86
nmake win32
POPD
gradle build

The resulting jSerialComm library can be found in the project directory build/libs under the name jSerialComm-{VERSION}.jar