This card was my final college project, used to control an industrial irrigation system. accepts Shield aArduino, XBee, optocoupled inputs, relay outputs and RS232 connection.The idea is to allow different forms of connectivity. Ethernet through an Ethernet Shield, wifi, bluetooth or Zigbee through the Xbee socket or high-power RF module through the RS232 connection. It can also be connected to an industrial controller via Ethernet or RS232.It all depends on the programming of the ATMega2560 microcontroller that can be loaded with the Arduino Mega Bootloader.Did I mention that it has a built-in real time clock?The power input has a rectifier bridge, so there is no need to worry about the polarity of the connection.