Argon is a small embedded RTOS with clean C and C++ APIs for Arm Cortex-M-based microcontrollers.

It is designed to be a clean preemptive RTOS kernel with a C++ API. A plain C API upon which the C++ API is built is also available. It is primarily targeted at microcontrollers with Arm Cortex-M processors. One of the key goals is for the source code to be highly readable, maintainable, and well commented.

The kernel objects provided by Argon are:

  • Thread
  • Semaphore
  • Mutex
  • Queue
  • Channel
  • Timer
  • Run Loop

Runloops enable very efficient use of threads, including waiting on multiple queues. Timers always (and only) run on runloops instead of a dedicated timer thread. This lets you control the thread and priority of timers.

Argon is open source software released with a BSD three-clause license.

The GitHub project is located at