Hi all, This is my first post. I am a newbie with Arduino.

Question: Is it possible to decode DTMF in software running on the Arduino? I plan to have a 3.5mm Jack connected somehow to the Arduino and decode the incoming signal. I intend to use the Arduino Nano. The tones will be coming in relatively slow so time to process is not a major factor. The incoming DTMF tones will act as a password to activate each of the relays/outputs.

Any advice, code example would be great. Thanks in advance.

I was just over there. Google is working.

There are lots of solutions based on a MT8870 tone decoder -- google will find this stuff

I have seen of discussion of direct tone detection using a Goertzel algorithm -- the wikipedia article has lots of useful links.

There is thread regarding audio spectrum analysis with Arduino here http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1289765675

Like Paul said -- google is your friend. Read what others have done first.

Thanks PaulS, Yes indeed.... Google appears to be working! Well played ;-)

Thanks Gardner, Ill be sure to check it out.