tjbaudio:
This board allows me to send some signals (in this case clock and data to an LED display) long distances and to multiple locations. I am also sending 12V power down the wire as well.The IO pins on the Arduino and other logic chips are only made to drive signals a few inches on a circuit board. The max485 chip we are using here can take those signals and convert them to an RS485 hardware layer. RS485 is good for several thousand feet and driving 30+ slave units. You can read more about RS485 on wiki and a few other pages, it has been around for a VERY long time.
I also added a 5V regulator so I can power the max485 chips and some external devices I use that are 5V only. If you have any more questions just ask.
ok but what's the practical use of it? Give me some example on what I can do with it?