In my current apartment our outside door to the building is locked. The only way in is with a key or pressing our apartment number from a set of buttons next to the door, it then rings inside the apartment, and someone then hits the door button inside our apartment and it unlocks the door. I would like to take an arduino and have it read the buzzer noise it makes when someone presses the outside button and then when it gets that input unlock the outside door.
I think I have a pretty good understanding of how to do the output. I would essentially hook up a relay to the arduino and when it gets a 5v signal it would switch open to allow the through flow that I can then hook a wire to each terminal to the Open Door button in our apartment. This would pretty much act like its pressing the button.
The part I need help with is the input. I'm not sure if the arduino can read the audio buzz that the speaker inside our apartment makes or if I need to somehow attach a microphone. Taking it one step further, I would maybe like to set it up so you have to press a certain pattern of beeps to make the door open but that can wait till after I get it initially figured out.
So basically I just need some suggestions and guidance on how to go about this and possibly even some help with the coding on the input side of things.
You're negating the security of the system. It'll let anyone into the building who presses your button, even a murderer!
Does your landlord approve of this?
Does his insurance provider approve of this?
Does the local Police's Crime Prevention Officer approve of this?
Once they press the button outside it sends a tone up to the apartment unit.
As far as security concerns, We live in a pretty safe area and a lot of the time people will press just every button on the board until someone lets them without even knowing who they are.
Perhaps you could work out a code, of sorts, where you have to call the appartment, leave it 2 seconds, call again, leave 5 seconds, call again, leave 2 seconds, call one last time and it opens.
Eventually that would be smarter but to start with I just want to be able to press the outside button and the door opens. It shouldn't be too difficult to do.
It isn't. A simple sound detector mounted near the speaker and a relay (with an appropriate resistor and diode) to short out the pins on your button in the room, would do the trick.
Then a bit of a mod to the sketch and you'd have it recognising your signature pattern.
Instead of "reading" the noise, can't you just connect something like a optocoupler or a relais parallel to the speaker? You're already tampering with it by connecting the "open door" relais to the terminal, why not do it with a couple extra wires?
As for security goes: Something like a secret knock would be better.
As for Nerdgasm goes: Hook it up to an arduino Ethernet connected to internet. You can be able to open your door with a touch of your smartphone, Watch_Dogs style!
You need to increase your home security - not reduce it further. Once a criminal gets inside the front door he can do the rest of his stuff (such as sniff your wifi for your bank details) in perfect privacy.
At the very least build a device that requires an obscure SMS from your phone - and, ideally one that changes regularly.
Robin2:
You need to increase your home security - not reduce it further. Once a criminal gets inside the front door he can do the rest of his stuff (such as sniff your wifi for your bank details) in perfect privacy.
At the very least build a device that requires an obscure SMS from your phone - and, ideally one that changes regularly.
Much simpler to carry a key.
...R
For sniffing wifi I don't need to be inside of an apartment, just near where I can receive the wifi.
The SMS is actually a great idea! And when you have a party you can even give a password that only works on that night and such...
Robin2:
You need to increase your home security - not reduce it further. Once a criminal gets inside the front door he can do the rest of his stuff (such as sniff your wifi for your bank details) in perfect privacy.
Or break into a flat [apartment] where there was no reply to the bell (they're out). Maybe HIS flat [apartment]!
At the very least build a device that requires an obscure SMS from your phone - and, ideally one that changes regularly.
But I'd still check with the landlord, as it might invalidate his landlord insurance and make the OP liable for any claims.
hey dstadtlander did you end up finishing this project? How did you go?
I've actually just finished my one, but my intercom was acting strange so i might change my tactics and use a servo to physically pick up the handset (my intercom requires you to pick up a handset before opening the doors) instead of using relays to mimic picking it up.
A bit about my version if you or anyone is interested: i ended up using a microphone to pick up volume levels which would then trigger picking up the handset and pressing the buttons to open the doors. I got it to monitor a long continuous noise so it wouldn't open the door if a single loud noise was made. That said, if there's a way to tap into the intercom speaker, i'd be grateful if someone could point me in the right direction.
I've also got a LAN module which will be used to put the device into a ready state instead of always leaving it on to open any time someone rings my apartment.
Thanks for the suggestion but that looks way over my level of skill. I was hoping that there'd be some way to basically detect voltage/current going to the speaker or something like that. A zero-crossing detector looks like it does something a little more than what i need? I'll probably just stick with the mic.