Useful referencies:
- http://arduino.cc/en/Hacking/BuildProcess
- http://electronics.stackexchange.com/questions/66983/how-to-discover-memory-overflow-errors-in-the-arduino-c-code
- https://www.inkling.com/read/arduino-cookbook-michael-margolis-2nd/chapter-17/recipe-17-1
- http://www.nongnu.org/avr-libc/user-manual/group__avr__pgmspace.html#ga652cbaf54885c73c7ebbefe73524fa22
- https://github.com/lthonway1/arduino/blob/master/WIFI_RAK410.cpp
- http://alexrdelp.com/?page_id=5
- http://arduino-info.wikispaces.com/RelayIsolation
- http://habrahabr.ru/post/189744/