IsixRTOS Open Source Free Realtime operating system

IsixRTOS is a small realtime and opensource operating system written by our team. ISIX is a complete development environment for embedded applications including: tiny kernel, peripheral drivers, integrated TCP/IP stack (LWIP), USB host and device stack, PPP driver etc. It is designed to be small enough to run on a microcontroller, but unlike similar systems it is flexible. The number of tasks and synchronization primitives are limited only by the available memory footprint. The core is written in ANSI C but C++ is fully supported.


IsixRTOS kernel

  • Small memory footprint Flash: 8kB
  • RAM: 256b+128b per task on ARMv7m architecture.
  • unlimited number of tasks / priorities limited only by available memory.
  •  Easily portable for any architecture.
  • Written in C, but C++ is fully supported (including exceptions, vectors)
  • OS objects: tasks / queues / semaphores/ mutexes / events.
  • Dedicated and optimized toolchain based on GCC.

Connectivity and drivers

  • TCP/IP stack (LWIP) integrated.
  •  TLS/SSL connections (mbedTLS).
  • Ethernet and PPP drivers (GSM).
  • USB host stack.
  • USB device stack.
  • SD card storage driver SDIO/SPI mode.
  •  I2S audio drivers.
  • I2C/SPI/Serial drivers.

C++ Middleware

  • MicroGUI – tiny framework for graphics applications development.
  • FsEnv – tiny file system for store configuration data in the flash memory.
  • EmeterLib – 3-phase, full quadrant energy meter library.
  • DSPLib – typical DSP algorithms for embeded systems.

IsixRTOS code

IsixRTOS kernel is provided under the LGPLv3 (with linking exception) open source license.  Source code is available on public repository.