In my first Instructable I want to show you how to build an cheap and easy Doorbell to Arduino 'Interface' so you can let your Arduinoproject get triggered through it or simply use your Arduino as a bell.
Almost endless possibilities :D
Step 1: What you need...
First of all you need the 'heart' of the interface, the relay.
-My Doorbell has 12V DC so I used a FTR F1CA012V which is a 'Double Pole Single Throw'-relay but you can use 'Normally-open' or 'Change-over'-relays as well.
You also need:
1x 100k Ohm Resistor
1x small 3 port luster terminal
some bell wire
about 20cm control wire cable
shrink tubes to isolate the contacts and protect the 'Interface'