Ethernut 1 - Embedded Ethernet Board


Atmel's AVR microcontrollers guarantee fast code execution combined with the lowest possible power consumption. Ethernut 1.3 is a cost efficient single board computer, which integrates the 8-bit AVR ATmega128 into an Ethernet network.

The minimalist design of Ethernut 1.3 is reduced to four essential components: Flash microcontroller, 32 kByte RAM, Ethernet controller and power supply.

Like all other Ethernut boards, it provides an extension connector for attaching additional hardware. Hence it is suitable for both the prototyping of your own hardware as well as for direct integration into your finished product.

Ethernut boards come in use where robustness, reliabilty and long-term availability play a vital role. Our in-house quality control procedures guarantee a consistently high level of reliability

The main characteristics of Ethernut 1.3 boards are:

  • Low power, high performance RISC CPU
  • 128 kByte Flash memory and 32 kByte RAM
  • Memory mapped Ethernet controller with 10BASE-T connector
  • RS-232 connector to control and monitor external devices
  • Expansion port with 21 digital I/O ports, including counter I/O, USART, SPI, I2C or PWM
  • 8 inputs to monitor analog values
  • Memory expansion bus
  • SPI and JTAG programming and debugging connectors
  • Single 9-12 V power supply


Application development is carried out in the high level programming language C, using either free GNU tools or the commercially supported ImageCraft compiler.

An active Open Source community developed and managed Nut/OS, a cooperative multithreading operating system with TCP/IP stack, which was specially designed with tiny embedded systems in mind. The well documented source code provides a convenient user interface, which is very similar to the C programming of desktop PC’s. Programmers will therefore quickly feel at ease operating this.

Although pre-configured for Ethernut 1.3, all important settings can be customized with just a few mouse clicks with an easy to use graphical interface available on Linux, Windows and Mac OS X PCs incorporating any special requirements. A complete Internet enabled web server needs less than 60 kByte Flash and 12 kByte RAM. This leaves enough space for ambitious product ideas, including a boot loader for the update of firmware via the network. Many useful example applications are included in the distribution.


The entire source code for the target system, as well as the hardware design, have a permissive BSD Licence. This is available for commercial products without any licence fees.

In contrast to some other Open Source licence models, there is no obligation to publish your own source code enhancements.


Ethernut 1.3H flyer
21.04.2011 | 0.51 MB | English

Ethernut 1.3H Hardware Manual
0.56 MB | English

Software und Tools

Nut/OS for Windows
Executable installation for Windows PCs.

Nut/OS for Linux and Mac OS X
Source code package for manual installation on Linux and Mac OS X.