microblx: hard realtime function blocks

Microblx is a lightweight and hard real-time safe function block framework for use-cases such as embedded control or signal processing. It provides generic and configurable code for typical challenges such as lock-free communication between different criticality domains, real-time safe logging or triggers with configurable POSIX realtime properties.

Main features:

• hard real-time safe: no run-time allocations or non-deterministic system calls
• simple model: everything is a block
• extensible: easy to add a new type, trigger block or connection
• composing applications: applications are described using a simple textual lanugage
• standard blocks and tools included:
  • communication: lock free buffers, POSIX message queues,
  • computations: PID controller, ramps, constants, random ...
  • triggers: periodic, passive incl. built in latency profiling
  • real-time safe logging
• no HAL: no arbitrary abstractions, just "configurable" POSIX
• minimal: tiny memory footprint, few dependencies, embedded-friendly

Documentation

The documentation is here or can be built locally (requires sphinx to be installed):

$ cd docs/
$ make html
Running Sphinx v1.8.5
...

There is also a ChangeLog which summarizes API changes or important features and a high-level roadmap.

Getting help

Please feel free to ask questions or report problems on the microblx mailing list:

https://groups.google.com/forum/#!forum/microblx

It is possible to subscribe by email by sending a mail to [email protected]

Related Projects

The following is a list of projects related to microblx:

• meta-microblx yocto layer
• microblx types for the Kinematics and Dynamics (KDL) library
• microblx connector blocks for ROS1
• microblx motion control blocks and usc models
• hardware
  • Kinova Kortex

Contributing

Contributions are very welcome. Please check that the following requirements are met:

• contributions must conform to the Linux kernel coding style.

• before submitting, please run the the tests (./run_tests.sh after installing) and static checking (make cppcheck, shouldn't output anything).

• the preferred ways of submitting patches is via the mailing list. If you must, a github merge request is OK too.

• please don't forget to add a line Signed-off-by: Random J Developer <[email protected]> to certify conformance with the Developer's Certificate of Origin 1.1 below.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or

(b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or

(c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it.

(d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.

License

See COPYING. The microblx core is licensed under the weak copyleft Mozilla Public License Version 2.0 (MPL-2.0). Standard blocks are mostly licensed under the permissive BSD 3-Clause "New" or "Revised" License or also under the MPLv2.

It boils down to the following. Use microblx as you wish in free and proprietary applications. You can distribute binary function blocks as modules. Only if you make changes to the core files (mostly the files in libubx/) library), and distribute these, then you are required to release these under the conditions of the MPL-2.0.

Acknowledgement

Microblx is considerably inspired by the OROCOS Real-Time Toolkit. Other influences are the IEC standards covering function block IEC-61131 and IEC-61499.

Microblx was supported by the European H2020 project RobMoSys via the COCORF (Component Composition for Real-time Function blocks) Integrated Technical Project.

This work was supported by the European FP7 projects RoboHow (FP7-ICT-288533), BRICS (FP7- ICT-231940), Rosetta (FP7-ICT-230902), Pick-n-Pack (FP7-NMP-311987) and euRobotics (FP7-ICT-248552).