Building OpenCPN for Android

These instructions describe how to build OpenCPN for Android on Ubuntu 24.04.

These build instructions are incomplete and under development. Users are encouraged to improve them by using the "Edit this page" button to submit patches and corrections.*

Build Environment Setup

1. Required Tools

Install basic build tools:

sudo apt update
sudo apt install -y \
  cmake \
  git \
  gettext \
  python3-pip \
  python3-venv \
  libxcb-cursor0 \
  libxcb-cursor-dev \
  libarchive-dev \
  libjpeg-dev \
  zlib1g-dev \
  libbz2-dev \
  libsndfile1-dev \
  libssl-dev \
  libgles1 \
  default-jdk

Get Java installation path:

sudo update-alternatives --config java
export JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64

2. Install and Configure Android Studio

Download Android Studio from Android Developer site
Extract and install according to Google’s instructions for Ubuntu
Launch Android Studio
In the welcome screen, click on "More Actions" > "SDK Manager"
In SDK Manager, under "SDK Tools" tab:
1. Check "NDK (Side by side)"
2. Check "Android SDK Command-line Tools"
3. Check "CMake"
4. Click "Apply" to download and install

Get path to Android NDK:

~/Android/Sdk/cmdline-tools/latest/bin/sdkmanager --list |grep ndk

Set environment variables:

export ANDROID_SDK_ROOT=$HOME/Android/Sdk
export ANDROID_NDK_VERSION=$(ls $ANDROID_SDK_ROOT/ndk | sort -V | tail -1)
export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/${ANDROID_NDK_VERSION}
export PATH=$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64/bin:$PATH

# API 30: Android 11 (2020)
# API 31: Android 12 (2021)
# API 33: Android 13 (2022)
# API 34: Android 14 (2023)

export OCPN_ANDROID_API=33  # Minimum Android API level to target

Create required NDK symlink:

android_x86_64="$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64"
ln -sf $android_x86_64/bin/llvm-ar \
     $android_x86_64/bin/aarch64-linux-android-ar

Building the Core Library

1. Clone the repository

git clone https://github.com/OpenCPN/OpenCPN.git
cd OpenCPN

2. Create build directory and configure

For armhf build - 32bit:

mkdir build-android-armhf
cd build-android-armhf
cmake \
  -DCMAKE_BUILD_TYPE=Release \
  -DOCPN_TARGET_TUPLE="Android-armhf;${OCPN_ANDROID_API};armhf" \
  -Dtool_base="$ANDROID_SDK_ROOT/ndk/${ANDROID_NDK_VERSION}/toolchains/llvm/prebuilt/linux-x86_64" \
  ..

For arm64 build - 64bit:

mkdir build-android-arm64
cd build-android-arm64
cmake \
  -DCMAKE_BUILD_TYPE=Release \
  -DOCPN_TARGET_TUPLE="Android-arm64;${OCPN_ANDROID_API};arm64" \
  -Dtool_base="$ANDROID_SDK_ROOT/ndk/${ANDROID_NDK_VERSION}/toolchains/llvm/prebuilt/linux-x86_64" \
  ..

3. Build the core library

make VERBOSE=1

Building the APK

After building the core library successfully:

1. Setup Qt environment

export QT_ANDROID_ROOT=/path/to/OpenCPN/cache/OCPNAndroidCoreBuildSupport/qt5

Create APK build directory

mkdir apk_build
cd apk_build

2. Generate Makefile with qmake

$QT_ANDROID_ROOT/android_armv7/bin/qmake \
  -makefile ../buildandroid/opencpn.pro \
  -o Makefile.android -r -spec android-g++ CONFIG+=debug

3. Build library and prepare for APK

make -f Makefile.android
make -f Makefile.android install INSTALL_ROOT=./apk_build

4. Create the APK

$QT_ANDROID_ROOT/android_armv7/bin/androiddeployqt \
  --input ./android-libopencpn.so-deployment-settings.json \
  --output ./apk_build \
  --android-platform android-19 \
  --deployment bundled

The final APK will be located at ./apk_build/bin/QtApp-debug.apk