rtlsdr433-native-gpl

GPL-2.0 Native Layer — RTL-SDR 433 Android App

This repository contains the native C/C++ signal-processing layer for the RTL-SDR 433 Android application.

It is published here to satisfy the GPL-2.0 written offer requirement. The RTL-SDR 433 app binary incorporates GPL-2.0 licensed code from rtl_433 and rtl-sdr. As required by GPL §3, the corresponding source code is made available here.

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What's in this repository

Path	Description	License
rtl433/	rtl_433 v25.12 (patched for Android, __EBCANDROID__)	GPL-2.0
rtl-sdr/	rtl-sdr library (patched for Android)	GPL-2.0
libusb-andro/	libusb 1.0.23 Android port	LGPL-2.1
android_bridge.c	EBC custom data_output_t → JSON → JNI callback	GPL-2.0
rtlsdr433.cpp	JNI entry points and C→Kotlin callbacks	GPL-2.0
librtlsdr_andro.c	Android USB open via libusb_wrap_sys_device(fd)	GPL-2.0
CMakeLists.txt	Android NDK build configuration	GPL-2.0

The proprietary Kotlin application layer (UI, billing, service logic) is not included here and is not covered by GPL-2.0.

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Android Patches (__EBCANDROID__)

All Android-specific patches in upstream rtl_433/rtl-sdr source files are guarded by #ifdef __EBCANDROID__. Key patches:

• rtl433/src/rtl_433.c — rtl433_start() / rtl433_android_close() entry block; acquire_callback bypass of mongoose (sdr_callback() called directly)
• rtl433/src/sdr.c (sdr.c in root) — sdr_open_rtl() opens via USB fd using rtlsdr_open2()
• rtl433/include/rtl_433.h — extern declarations + Android API prototypes
• rtl433/src/output_rtltcp.c — pthread_cancel guarded for Bionic

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Building

This directory is consumed by the Android NDK build system. It is not intended to build standalone. To build just the native library for inspection purposes, you need:

• Android NDK ≥ 29.0.14206865
• CMake ≥ 4.1.2
• Include this directory as the externalNativeBuild.cmake.path in an Android module's build.gradle

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Version History

Tag	App Version	Date
v1.0.10	1.0.10	2026-04-18
v1.0.9	1.0.9	2026-04-18

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License

The files in this repository are derived from or link with GPL-2.0 licensed software and are distributed under the GNU General Public License version 2.0.

Copyright (C) 2025 Christian Ebner <info@ebctech.eu>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

Full GPL-2.0 text: rtl433/COPYING · Full LGPL-2.1 text: libusb-andro/COPYING

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Contact

ebctech.eu · info@ebctech.eu · https://www.ebctech.eu

For the RTL-SDR 433 app: Google Play Store