July 11, 2010

Easy Ethernet Crossover Adapter

Ordered an Ethernet Shield for Arduino... So I need an Ethernet cross cable... but I don't feel like making my own (I have plenty of straight cables around). That's why I moved to make an Ethernet Crossover Adapter, to be able to use any straight cable as cross-cable when needed.

Plenty of info on the Web on Ethernet Cables. From here the pinout of an Ethernet Plug:


And here is the different pin mapping of a straight through cable and a crossover cable:


So I've started sacrifying one cable to get this one (the paper strips for easy pin reference):


Using a normal ethernet patch-panel socket it's very easy to make connections...


...just passing the cables in the proper places following the Crossover pinout connection schema...


...pressing them well and cutting the extra cables...


...then using some insulating tape to finish it up:


To test it I've used a cheap LAN Cable Tester got from the bay. First, here is a straight cable:


and here is how it is connected (straight through pinout):


Then, after adding the Cross Adapter to the cable:


here is the new connections (crossover pinout):


Done!