Embedded Ethernet Boards

All published board designs are currently based on Atmel's ATmega128 8-bit microcontroller. This situation will probably change in the near future when the official release of the software becomes available for other platforms, like the Renesas H8/300, the ARM7TDMI, or the Motorola Coldfire.


Ethernut 1.3

The Ethernut 1.3 board has been developed by egnite Software GmbH and replaced the original ATmega103 design after this chip became obsolete. For Ethernet it uses Realtek's the RTL8019AS controller, which provides 10 Mbps. The ATmega128 provides 4 kByte internal RAM only, which is not sufficient for an Embedded Ethernet System. Thus, the board is equipped with 32 kByte external RAM.

One advantage of the Ethernut is, that all general purpose I/O ports as well as the external address and data bus are available at the expansion connector, which makes the board ideally suited for applications, which require some extra custom hardware to be attached. In addtion a RS232 port is available on a standard DB-9 connector.

Ethernut 1.3


Ethernut 2.x

In 2003 Ethernut 2.0 has been designed by egnite as a compatible replacement for Ethernut 1.3 for two main purposes: First, it offers fast 100 Mbps Ethernet based on SMSC's LAN91C111 Ethernet controller. Second, 480 kBytes banked RAM have been added to support new applications like streaming MP3 encoded audio data from Internet Shoutcast servers. The board also offers an additional RS485 interface.

Since August 2004 it has been replaced by Ethernut 2.1, which offers an additional 512 kBytes of serial flash memory.

The penality for all these enhancements is an increased power consumption and heat dissipation, mainly caused by the fast Ethernet interface.

Ethernut 2.0


Charon Development Board


The Charon Development Board serves as a motherboard for the Charon I and Charon II Module. It comes with the required Ethernet transformer and RJ45 connector for the Charon Modules and additionally provides two RS232 ports, LCD interface, 8 bit dip switch input, 8 bit LED output, JTAG and ISP connector.

Charon DB


Poor Man's Ethernut

Some people argue, that even buying the bare Ethernut PCB, Ethernet controller and transformer etc. from egnite is many times the price of an ISA network card with all this already on board. Too true. So, how about using any cheap ATmega board and add an ISA connector to it.

Jochen Beck contributed all details to build such a real cheap solution.

ISA Adapter


Comparision Table

Feature Ethernut 1.3 G Ethernut 2.1 B Charon II DB Poor Man's
10 Mbit Ethernet Yes, RJ-45 Yes, RJ-45 Yes, RJ-45 Yes, RJ-45 and BNC
100 Mbit Ethernet No Yes, onboard No Depends on ISA board used
Onboard RAM 32 kByte 32 kByte plus 480 kByte banked RAM 32 kByte Depends on ATmega board used
Additional Non-Volatile Memory No 512 kByte serial Flash Optional Depends on ATmega board used
LAN Controller EEPROM No, MAC stored in ATmega EEPROM No, MAC stored in ATmega EEPROM Yes Yes
RS232 One onboard, second with external level shifter and connector One onboard, second with adapter cable Two onboard Depends on ATmega board used
RS485 External level shifter and connector required Yes, onboard No Depends on ATmega board used
General purpose I/O ports 31 31 Up to 27 Depends on ATmega board used
Address-/Databus Yes Yes No Depends on ATmega board used
Power Supply 8-12V 150mA 8-12V 400mA 9-15V 150mA Depends on boards used
Dimension mm 98 x 78 98 x 78 115 x 85 Large




Ethernut Add-On


Programming Adapters

Check this link for more information.



Medianut 1.1

The pdf  Medianut board can be attached to the Ethernut expansion connector and contains a VS1001K MP3 decoder, a Sony compatible infrared remote control receiver, a simple keyboard and a LCD interface.

A step by step guide on how to build a stand-alone Embedded Internet Radio is available here.

Medianut 1.1


Datanut 1.1

The Datanut board is currently under development. It can be attached to the Ethernut expansion connector and provides an IDE and a CompactFlash interface.

Datanut 1.0


Other Hardware


Porting Nut/OS to the GameBoy Advance.

Gameboy Port