http://www.reality.be/elo/labos2/schematics3.htm
http://topprojects.blogspot.com/2009/05/electronics-and-communication-ece.html
http://www.electronics-lab.com
http://www.kolumbus.fi/michael.fletcher/index.html
http://mitglied.multimania.de/suschman/howto/serial-laser/Serial_Laser.htm
http://www.scienceprog.com/page/46/
http://www.satsleuth.com/Misc.htm
http://amatirindonesia.blogspot.com/2010/05/komunikasi-via-jala-jala-listrik.html
