Learning About Arduino Ethernet

(The following notes refer to the ENC28J60, see more recent progress with the WIZ810MJ on Learning About Arduino WIZ810MJ.)

My notes about Arduino and Ethernet.

Interfacing with the ENC28J60 -- Useful Arduino forum post started by xSmurf. (Initial code) (Up-to-date Trac instance)

An AVR microcontroller based Ethernet device -- Comprehensive generic AVR ethernet design.

Parts sources

Parts suppliers (who sample) from xSmurf: @@ TODO: Tidy this up with links

the ENC28J60 at microchip

the crystal (you need a 25Mhz xtal for the enc) can be obtained at foxonline.com (or needasample.com) with SKU FOXSLF/250F-20.

the MagJack comes from erni.com and is sku 203322 (Note: this maybe an outdated part number)

luxtronic.com (might be luxtronics.com) have magjacks too

"with that, all you need is a few resistors and caps and a 3.3v supply (which you have if you have a Diecimila)" -- "in the passive stuff, you'll want 2x~20pF caps for the xtal, a 10µF polarized caps, 2x 10µF, 2x 150ohm, 4x 50ohm, 2x 10k ohm, 1x 2.7K ohm, if possible a 0.5cm ferrite bead with about 6 turns of thin wire"

IP/ICMP Checksum-related resources

A valid reply packet (with correct checksum 0x4b9c—created using Python Impacket library) :

45 00 00 54 3c 88 00 00 ff 01 39 ce c0 a8 00 7e c0 a8 00 0c 00 00 4b 9c 90 66 00 00 50 52 ea 46 f0 60 0e 00 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37

The code:

#!/usr/bin/python

import sys
sys.path.insert(0, 'Impacket-0.9.6.0')

from impacket import ImpactPacket

icmp = ImpactPacket.ICMP()
ip = ImpactPacket.IP()
ip.set_ip_src("192.168.0.126")
ip.set_ip_dst("192.168.0.12")
icmp.set_icmp_type(icmp.ICMP_ECHOREPLY)
icmp.contains(ImpactPacket.Data('PR\xeaF\xf0`\x0e\x00\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./01234567'))
ip.set_ip_id(0x3c88)
ip.set_ip_ttl(64)
ip.contains(icmp)
icmp.set_icmp_id(0x9066)
icmp.set_icmp_cksum(0)
icmp.auto_checksum = 1
#print repr(ip.get_packet())

print " ".join(["%02x" % ord(c) for c in ip.get_packet()])

Output:

45 00 00 54 3c 88 00 00 40 01 bc 46 c0 a8 00 7e c0 a8 00 0c 00 00 4b 9c 90 66 00 00 50 52 ea 46 f0 60 0e 00 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37

Learning About Arduino Ethernet

Parts sources

IP/ICMP Checksum-related resources

Links