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Since August 2004 it has been replaced by Ethernut 2.1, which offers an additional 512 kBytes of serial flash memory.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

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.

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.

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 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.

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.

Other Hardware

Porting Nut/OS to the GameBoy Advance.