voice activated door opener

[mnhassan]

hello floks, am doing a project about voice activated door opener, without using any voice recognition, i really need help about how to start, any ideas? ;)

[Theatronics]

Voice activated without recognizing a voice?
Ok, why not.

I am going to assume you mean that if you say (OPEN)
The door will open for a while and then close again.

You might also want to add ‘CLOSE’ later but that is
More complex.

What you are looking for, I think, is a sound activated circuit.
The sound of a voice would be the trigger.

The key of course is to select some attribute of the voice that is unique
Enough that the door will not trigger to just any word or sound.

In English ‘OPEN’ is a long vowel sound with a hard percussion ‘P’  in the middle, and then a soft ‘nnnnn’ sound.

Looking at a scope and a frequency range there are 3 distinct events.

You could do something like this.

Set up a series of notch pass filters, similar to a graphic EQ.
Then say the word ‘OPEN” several times and tune the notches so that they switch on and off as you say the word and different frequencies are accented and muted.

Have the outputs light LEDs for testing.

Then feed the outputs into series of logic gates (And gates)

Lets say you end up with 5 notch filters.  Named (a,b,c,d and e)

O triggers a,b,c, and e
Ph triggers all of them
En triggers c,d and e

Then set up your logic thus:
Key 1 = A and B and C and E and not D
Key 2 = A and B and C and D and E
Key 3 = C and D and E and not A and Not B

Then a sequential circuit can be set up where the Keys need to be triggered
In the proper sequence in order to get the system to output a signal.  (A series of flipflops would work)

Personally I would use something like this:
http://www.sensoryinc.com/

This device has VR built into it and is easy to set up.  You can have it Open, Close, Lock , Unlock and ring the door bell and still have space left over.

Good Luck

-Mike