Nut/OS

Features

Nut/OS is based on an intentionally simple RTOS kernel, which provides a minimum of services to run Nut/Net, the TCP/IP stack. It's features include:

Coperative multithreading
Deterministic interrupt response times
Priority based event handling
Periodic and one-shot timers
Dynamic memory management

Main features of the TCP/IP stack are:

Base protocols Ethernet, ARP, IP, ICMP, UDP, TCP and PPP
User protocols DHCP, DNS, SNTP, SMTP, FTP, SYSLOG, HTTP and others
Socket API
Host, net and default routing

Nut/OS is a modular operating system. Instead of providing a fixed kernel block, all code is packed in libraries. Only those parts are linked to the final binary image, which are directly or indirectly referenced by the application. This guarantees the lowest possible footprint. Ernst Stippl regularly publishes related figures on his web site at www.es-business.com/ethernut/.

Standard C libraries like newlib or avr-libc are supported and allow to write highly portable applications. While direct hardware access and native interrupts are possible in application code, the system offers ready-to-use drivers for a large number of devices, including:

Ethernet controllers
UART devices with RS-232 handshake and RS-485 mode
SPI, I2C and CAN busses
MultiMedia and SD cards
Hardware and software audio codecs
Analog-to-digital converters
Serial flash memory
Realtime clocks
Infrared remote controls
Watchdogs and reset controllers
Character displays
GPIO and interrupt control
Modem control

Note, that not all drivers may be available on all platforms. The following microcontrollers are actively supported:

ATmega103, ATmega128, ATmega2561, AT90CAN128
AT91SAM7S, AT91SAM7SE, AT91SAM7X
AT91SAM9260, AT91SAM9XE
Gameboy Advance

The system is highly configurable and may work on other hardware too. Support for AVR32 is currently under development and a version for the Freescale Coldfire may become available as well. In addition it is possible to run Nut/OS applications on Linux.

In order to hide hardware specific details from application code, an almost complete C stdio API is available, which provides:

C99 integer types and optional floating point I/O
File system support, including FAT
Low level functions and streams on devices, TCP sockets and files

Nut/OS is perrmanently enhanced by an active community. The following features are currently not available, but planned for future releases or currently under development:

Graphical user interface
USB stack
IPv6
Encryption
Wireless LAN

Additional Documents

New or recently updated

Nut/OS Software Manual
How to install and use Nut/OS.

SPI Bus Support
Technical details about SPI drivers.

ARM Exception Handling
Nut/OS doesn't provide any exception handling by default. This document shows how to implement an exception handler within your application.

ARM GCC Inline Assembler Cookbook
The GNU C compiler for ARM RISC processors offers to embed assembly language code into C programs. This cool feature may be used for manually optimizing time critical parts of the software or to use specific processor instruction, which are not available in the C language.

Partly outdated

Nut Programmable Logic
This tutorial teaches you to modify the CPLD on Ethernut 3.

MP3 Streaming
A step by step guide on how to build a stand-alone Embedded Internet Radio.

Setting up PPP
This paper provides helpful information about how to get started with Ethernut's PPP.

SAM Internet Radio
Implementing an Internet Radio on the AT91SAM9260 and AT91SAM7X Evaluation Kits.

Nut/OS Events
This paper explains Nut/OS event handling internals.

CPU and Memory Requirements

Nut/OS Threads, Events and Timers
Recommended reading for application programmers.

Nut/OS Memory Considerations
Includes a design proposal for bank switched RAM.

Nut/OS

Features

Additional Documents

New or recently updated

More documents

Partly outdated