Jeff Viezel

Thanks - the info was very helpful.

Also found the following which explains how to hook it up.

http://www.raspberrypi.org/forum/viewtopic.php?f=44&t=61310

Thanks - this info is very helpful. I am attempting to build a garage door opener using a fingerprint scanner. I finally finished the code to drive the fingerprint scanner using my RPi and it's time to move on to the garage door. When the fingerprint scanner gets a match, I want a relay to close and the garage door to open.

My question is if I need any resistor between my RPi and the relay switch, or can I simply attach the 5v GPIO output to the relay and one of the GPIO pins to the relay switch? I thought I had read somewhere that if you use 5V output of the RPi, you should use a resistor to limit the voltage when connecting other GPIO pins or you may damage your RPi

Any help would be greatly appreciated