The 28J60 is the chip used in Nuelectronics EtherShield and JeeLabs EtherCard. I started using it for the same reason that everyone else does. It’s cheap. I’m not going to blow your mind in this post with technical details on the chip or the libraries associated with it. My goal is simply to save you a little time if you have a board with this device parked on top of it. I really like the $25 version from JeeLabs. Here is a link to it via Modern Device: http://shop.moderndevice.com/products/jeelabs-ether-card
The first place I would recommend stopping is the Nulectroniccs site for the basic library:
Next stop should be Simon Monk’s site for a library that simplifies the first library. I know that seems weird but trust me, the difference this makes for simple tasks is ridiculous: http://srmonk.blogspot.com/2010/03/simplified-ethernet-library-for-28j60.html
The final stop in this tour to save a buck should probably be here for some inspiration: https://github.com/thiseldo/EtherShield_RESTduino
If you survived all of that clicking and downloading and reading you should now have the ability to monitor an control digital and analog pins via the web.
** An important note is that if you are on a case sensitive Linux machine like me you’re going to have to clean up some of the references to the word “ethershield” in these libraries and sketches. “EtherShield”, “etherShield” and a few other versions of the word are mixed in there. Change a few file names, do a little find and replace and voila! You are in the club of people willing to spend 2 hours of labor to save $20. There’s nothing wrong with that, by the way. I’ve spent days disassembling things worth less than $5 just to see what’s inside. Later, Rob