220V AC detection

Forum 2005-2010 (read only) General Frequently-Asked Questions
10

Cheap and easy: http://cgi.ebay.com/USB-AC-Power-Supply-Wall-Adapter-MP3-Charger-US-2P-Plug-/300422883221?pt=Other_MP3_Player_Accessories&hash=item45f2996795

:smiley:

And wire the +5 to a digital input in arduino and gnd to gnd of course