BeRTOS

BeRTOS is a completely free, open source, real time operating system (RTOS) suitable for embedded platforms. It runs on many microprocessors and microcontrollers, ranging from 8 bits to 32 bits CPUs and even PCs.

BeRTOS was born as a collection of useful, highly optimized and fine-tuned
libraries for embedded systems. Each library had its own scope and could be
used singularly in a project, though they were also meant to cooperate to
build the whole underlying software layer commonly called "operating system".

We have grown it following our guidelines: simplicity and beauty. These guidelines made it possible to evolve it in a full-featured real time operating system, with more modularity than many other embedded OSes, without giving up reliability and performance.

To achieve the highest possible reusability, most BeRTOS components are
designed for fine-grained modularity and minimal external dependencies.
Most non-essential features can be configured out for application with small
memory footprint requirements.

Features:

• multitasking kernel with IPC, semaphores, priority levels;
• a comprehensive set of generic drivers for a wide range of devices, which can be easily customized to the actual hardware: timer, serial, adc, ntc, pwm, stepper motors, dc motors, lcd, keyboards, buzzer, eeprom;
• full graphic subsystem for simple displays, with font support, bitmaps, clipping, text formatting, interactive menus;
• simple console with command parser;
• readline-like support for command history;
• entropy generator and random numbers generator optimized for embedded systems;
• checksumming and hashing functions (CRC, MD2);
• full hash-table implementation with double-hashing collision resolution;
• XMODEM protocol implementation;
• RLE compression algorithm.

What is new in this release:

• New supported compiler: experimental support for IAR on Cortex-M3 CPU
• New CPU family: support for AVR XMega CPUs.
• New CPU: Atmel SAM3X
• New CPU: STM32F100RB
• New feature: LWIP network stack.
• New feature: priority inheritance protocol for semaphores.
• New driver: SAM7X EMAC driver.
• New driver: seven segment display. You can now drive many seven segment items with one driver.
• New driver: NAND KBlock driver.
• New driver: Himax HX8347 LCD controller.
• New module: TFTP server. You can use it to implement a bootloader that updates the firmware using network transfers
• New interface for PWM driver
• Many bugfixes in drivers and wizard

What is new in version 2.6.1:

• New supported CPU: Atmel SAM3N Cortex-M3
• New supported CPU: ATmega1280 (Contributed by Fabio Bizzi)
• New supported board: Arduino Mega (Contributed by Fabio Bizzi)
• New module: USB support for STM32.
• New driver: usb-serial driver
• New driver: usb keyboard device. You can use BeRTOS to create a usb keyboard.
• New driver: usb mouse device. You can use BeRTOS to create a usb mouse.
• New interface for block devices: KBlock
• New module: generic event completion infrastructure
• New and more flexible I2C API.
• New module: BitArray. Easily manipulate unlimited length arrays of bits.
• Fixed serial driver in ATmega32
• New supported programmers in BeRTOS SDK: Segger JLink, Atmel SAM-ICE, IAR J-Link

What is new in version 2.5.1:

• This release fixes a build bug in empty and kernel presets for lm3s-based projects. All users are encouraged to upgrade their existing installations.

What is new in version 2.4.0:

• Synchronous Timer Scheduler: convenient API to perform periodic tasks on very tiny embedded systems.
• Preemptive Scheduler: a long awaited feature is now in BeRTOS!
• New driver: Texas Instruments TLV5618 DAC module
• Add heap module to the Wizard: now you can use and configure the BeRTOS dynamic memory allocator directly from the wizard.
• Dynamic memory allocation for processes: you don't need to provide a memory area for your processes, the stack will be automatically created by the kernel.

What is new in version 2.3.0:

• This release adds the CRC-CCITT algorithm (a standard CRC algorithm), the AX25 protocol (a communication protocol used extensively on amateur packet radio networks), the AFSK1200 modem driver (a modem built on top of AFSK modulation), NMEA-0183 (a data parser for GPS packets based on the nmeap library), National LM75 and Texas Instruments TMP123 temperature sensor drivers, a Freescale MPxx6115A pressure sensor driver and the KFileMem module (a KFile interface on a memory buffer).
• The Website is now available in English.

What is new in version 2.0.0:

• This is a major refactoring version.
• There are huge changes in interfaces and many new features.
• This includes major kernel refactoring, new peripheral drivers, a new I2C driver and interface, a PCF8574 I2C port expander, an FT245 USB to parallel interface, a new PID controller algorithm, a new configuration infrastructure, a new testing harness, a new logging infrastructure, and an initial experimental embedded filesystem (BattFs).