This is a fork of the FreeModbus protocol stack, extended with ports for:
- ADuc702x processors
- STM32 processors using CMake build system
FreeModbus is a Modbus ASCII/RTU and Modbus TCP implementation for embedded systems. It provides an implementation of the Modbus Application Protocol v1.1a and supports both the RTU and ASCII transmission modes as defined in the Modbus over serial line specification 1.0.
The STM32 CMake port is located in the demo/STM32_CMAKE directory and provides:
- A generic implementation that can target multiple STM32 families
- HAL-based peripheral access for portability
- Integration with CMake build systems
- Simple demo application
- Support for the STM32G4 family (tested on Nucleo-G431RB)
Complete documentation of the original FreeModbus implementation can be found in the doc/html directory.
For information specific to the STM32 CMake port, refer to the demo/STM32_CMAKE/README.md file.
FreeModbus uses a multi-license approach:
- Core Protocol Stack (in
modbus/directory): BSD License - Port Implementations (in
demo/*/port/directories): Generally LGPL License - Demo Applications (in
demo/*/directories): Generally GPL License
This licensing structure allows:
- Using the core protocol stack in both open-source and proprietary applications (BSD)
- Using the port implementations in proprietary applications with some restrictions (LGPL)
- Using the demo applications only in GPL-compatible projects (GPL)
Always check the license header in individual source files for specific licensing terms.