Microcontroller: ATMEGA2560 with 16 MHz crystal with On-Board USBASP Programmer. Power: 7 to 15 VDC with Reverse Polarity Protection. 2.4GHz ZigBee (XBee) wireless module adaptor 2×16 Character Alphanumeric LCD. SD card Holder. CH340G USB to Serial converter. ESP8255 Adaptor interface with USB to Serial Converter.