www.keithlantz.net – computer science and mathematics, We had a few Halloween decorations with push button switches that we networked via an Arduino Uno. Three of the relays from the relay shield were used to activate a Grim Reaper and two sets of skulls. The push button from each decoration was cut and discarded. One of the wires coming from a decoration was connected to the common and the other to the normally open contact of a relay.
[caption id=attachment_2755 align=aligncenter width=300] An Arduino Uno, an Ethernet Shield, and a Relay Shi.