Sniff Ethernet With A Throwing Star

[Michael Ossmann] came up with a nifty little device that arranges RJ45 plugs into a plus shape for the intent of sniffing Ethernet packets, and named it the “Throwing Star LAN Tap”. While the original design worked fine it does suffer some limitations such as being limited to 10/100 base networks, and one way only. This new version of the “Throwing Star LAN Tap” fixes those and adds some much needed convenience.

Gone are the male plugs, which requires couplers and are prone to break, and fiddly splices in favor of a throwing star shaped pcb, and female sockets. 1000 base networks are supported, but due to the workings of 1000 base and wanting to keep the device passive, capacitors are added to filter out the signal and force the network to drop down to 100 base. Sure, it may be an ugly hack, but it’s an ugly hack that fits in your pocket.

Ethernet Connection Using Capacitive Coupling

Wanting to save space and weight on his project build [Florin] set out to find a way to add Ethernet connectivity without the magnetics. His ill-advised first try involved directly coupling two switches, frying both in the process. After some research he found that Ethernet hardware manufacturers have considered the need for devices without the magnetics and there are several application notes available on the subject. [Florin] followed the information that Realtek has for their devices and learned that they can be couple capacitively. After depopulating the magnetics from a second pair of switches he wired up some resistor-capacitor networks on a breadboard and got the connecting to work.

Stepping Beyond The Ethernet Shield

We’ve said it time and again, the Arduino is a prototyping platform. In that spirit, [Doug Jackson] shows you how to conserve the expensive Arduino board and Ethernet shield by building your own Arduino Ethernet module. You may remember the ENC28j60 as a NIC for your microcontrollers. [Doug’s] board makes use of that chip and adds an ATmega168 with a crystal, power regulator, breakout pins, and even a few DIP switches which can come in quite handy.

Simple Way To Fix That Broken Ethernet Cable

Chances are you’ve come across an Ethernet cable where the small plastic tab that holds the plug in place has broken off. We have a crimper on hand and usually just throw on a new RJ45 connector but [Laxap] found a simple alternative to fix Ethernet plugs. By using a couple of correctly sized cable ties you can secure the damaged connector without replacement. The boxy locking mechanism on the end of the cable tie is used as the catch, slimmed down with the help of an X-Acto knife or razor blade. Once you’ve got the right fit, use a second cable tie to secure it to the Ethernet cable. Simple is brilliant.

[Thanks Password]

Official Arduino Ethernet Shield

ethernetshield
Arduino has just released an official ethernet shield. It’s based on the same WizNet W5100 chip that was used in the tiny ethernet board we covered earlier. The W5100 handles the full IP stack and can do TCP or UDP with four simultaneous sockets. The board has a power indicator plus six LEDs to debug the connection. It works with the standard ethernet library. The reset button resets the shield and the Arduino. The SD adapter is not currently supported by the Arduino software.

Tiny Arduino Ethernet Board

[sgk] built this tiny ethernet board to be used with the Arduino. It’s based on a WIZnet W5100 chip. The chip handles all of the TCP/IP communication and you talk to it via SPI. It’s compatible with the standard Arduino ethernet library. [sgk] hand soldered these boards including the 80pin LQFP main chip. His next project is to put the AVR and W5100 all on the same board. It sounds like he’ll use components larger than 1005 though.