The Arduino Ethernet is a microcontroller board based on the ATmega328, it differs from other boards in that it does not have an onboard USB-to-serial driver chip, but has a Wiznet Ethernet interface (the same interface found on the Ethernet shield).
It has 14 digital input/output pins, 6 analog inputs, a 16 MHz crystal oscillator, a RJ45 connection, a power jack, an ICSP header, and a reset button.
Pins 10, 11, 12 and 13 are reserved for interfacing with the Ethernet module and should not be used otherwise. This reduces the number of available pins to 9, with 4 available as PWM outputs.
An optional Power over Ethernet module can be added to the board as well.
An onboard microSD card reader, which can be used to store files for serving over the network, is accessible through the SD Library. Pin 10 is reserved for the Wiznet interface, SS for the SD card is on Pin 4.
The 6-pin serial programming header is compatible with the USB Serial adapter and also with the FTDI USB cables or with Sparkfun and Adafruit FTDI-style basic USB-to-serial breakout boards. It features support for automatic reset, allowing sketches to be uploaded without pressing the reset button on the board. When plugged into a USB to Serial adapter, the Arduino Ethernet is powered from the adapter.
|Clock Speed||16 MHz|
|Extra features||Power Over Ethernet ready Magnetic Jack|
|Input Voltage (recommended)||7-12V|
|Input Voltage (limits)||6-20V|
|Input Voltage PoE (limits)||36-57V|
|DC Current per I/O Pin||40 mA|
|DC Current for 3.3V Pin||50 mA|
|Flash Memory||32 KB of which 0.5 KB used by bootloader|
|External memory||Micro SD card, with active voltage translators|
|Digital I/O Pins||14 (of which 4 provide PWM output)|
|Analog Input Pins||6|
|Pins reserved||10 to 13 used for SPI, 4 used for SD card, 2 W5100 interrupt (when bridged)|
|Internet connectivity||W5100 TCP/IP Embedded Ethernet Controller|